from:"R C"



On 11/6/20 8:08 PM, andy pugh wrote:

On Sat, 7 Nov 2020 at 02:48, R C  wrote:


You will need a cable that has ALL 25 pins connected (one to one),

that's called a straight through

It's a bit more than that, as some parallel cables only have enough
wires to work a printer, and leave some out.


that would not be a parallel straight through, you would need a db25 
straight through





You need an IEEE 1284 cable. (then buzz it through with a multimeter
when it arrives, and if it _isn't_ IEEE 1284 you have grounds for
return/refund.

Nah,  you just need a  db25 straight through...  or a   db25 extension 
cable,  which is the same thing.



Ron



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Re: [Emc-users] limit switch configuration on lathe in linxcnc (2.7)


ok...


but,  if I  turn the  lathe an computer off..   then restart them   and 
want to home the lathe..  it wouldn't know how to do that unless it hit 
a limit switch?





On 11/6/20 8:03 PM, Jon Elson wrote:

On 11/06/2020 07:33 PM, R C wrote:

I noticed I can (in stepconf,  which I shouldn't use of course...)


That I can use the limit switches as 'home'  for an axis only.


Unless I am understanding this wrong,  I figured  an axis would 
travel there  and when it hits it thinks "I am home"  ?



There are a couple things you have to do to the .INI file tomake a 
shared home/limit work.  First, you have to set
HOME_IGNORE_LIMITS = YES in each axis section.  Then, you have to set 
the HOME_OFFSET to a value that makes the axis back away from the 
switch enough so that it is not tripped when it gets to the offset 
position.  This allows the axis to ignore the limit switch DURING the 
home sequence, and leave the axis such that the switch is not tripped 
when it arrives at the home position.


Once the axis is homed, you can then jog around manually and observe 
the machine coordinates when at the extent you want to set as the soft 
limit range, and enter these values into the .INI file for

MIN_LIMIT and MAX_LIMIT to set your desired soft limits.

Jon


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Re: [Emc-users] quick question on parallel port cables

you can also look for a "db25 extension cable" those are straight 
through.   they typically come  F-M,  but you can use a gender changer 
at either end if needed


(but I have seen them FF MM FM) and are inexpensive.



On 11/6/20 7:10 PM, andrew beck wrote:

hey everyone

I found that I am missing a parallel port cable for between one of my mesa
5i25 and 7i77 cards

I am in new zealand and don't really want to buy a cable from america as
shipping is heaps just for a cable.  if I buy one locally what am I looking
for?

here are some options

pbtech parallel port cable




I have heard that you can't use just any parallel port cable as some have
the wires crossed inside

regards

Andrew

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Re: [Emc-users] quick question on parallel port cables



On 11/6/20 7:37 PM, Robert Murphy wrote:

A null modem cable wont be any good as they will have RX & TX crossed,
and is primarily a cable for serial use.

You will need a cable that has ALL 25 pins connected (one to one),



that's called a straight through



some
dodgy parallel cables may have the GND lines all connected together.

Here's one from element14:

https://nz.element14.com/multicomp/spc20023/computer-cable-parallel-10ft-gray/dp/1189912?ost=1189912 



http://www.farnell.com/datasheets/1657741.pdf

On 7/11/20 1:10 pm, andrew beck wrote:

hey everyone

I found that I am missing a parallel port cable for between one of my 
mesa

5i25 and 7i77 cards

I am in new zealand and don't really want to buy a cable from america as
shipping is heaps just for a cable.  if I buy one locally what am I 
looking

for?

here are some options

pbtech parallel port cable
 





I have heard that you can't use just any parallel port cable as some 
have

the wires crossed inside

regards

Andrew

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Re: [Emc-users] quick question on parallel port cables


looks like you'd need a db25 straight through.


A null modem cable has certain wires hard wired (typical to ground), you 
probably don't want that.


On 11/6/20 7:10 PM, andrew beck wrote:

hey everyone

I found that I am missing a parallel port cable for between one of my mesa
5i25 and 7i77 cards

I am in new zealand and don't really want to buy a cable from america as
shipping is heaps just for a cable.  if I buy one locally what am I looking
for?

here are some options

pbtech parallel port cable




I have heard that you can't use just any parallel port cable as some have
the wires crossed inside



correct..   because of the handshake protocol used.


Most likely you want a straight through




regards

Andrew

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Re: [Emc-users] limit switch configuration on lathe in linxcnc (2.7)


I noticed I can (in stepconf,  which I shouldn't use of course...)


That I can use the limit switches as 'home'  for an axis only.


Unless I am understanding this wrong,  I figured  an axis would travel 
there  and when it hits it thinks "I am home"  ?



I see one axis move in the beginning of "homing"  very slow (VERY 
slow)..  and the wrong direction



Is that the route I want to g?   I would  like the functionality of..   
"click home button"   and it moves to the home location.



thanks,


Ron



On 11/6/20 3:48 PM, Phill Carter wrote:

ah,  yes,  I have not set any soft limits in the new configuration yet. Also 
wonder how to do that.


For example, I have a mill, also a sherline, without limit switches which I "return 
home" every time I am done, and then home the axes when I start.

I thought I could use the limit switches also as homing switches.

There is a good diagram of of a shared home/limit switch setup here: 
>
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Re: [Emc-users] limit switch configuration on lathe in linxcnc (2.7)

well, the X and Z axis only have one limit switch, which pretty much
seems like it is a home/limit-switch because of where they are

On 11/6/20 5:23 PM, Leonardo Marsaglia wrote:

ah, yes, I have not set any soft limits in the new configuration yet.
Also wonder how to do that.

In the case of the lathe it's pretty easy if you have the following config
wich is the one I'm using:

HARD LIMITS = Negative limit switch |---Z axis real
travel - Home switch ---|Positive limit switch
SOFT LIMITS = |-
Z axis limited travel--|

I don't know if the diagram makes any sense, but I tried to illustrate the
loss on the full travel of the machine when setting the soft limits. Soft
limits are pretty simple in this configuration, basically you set them in
the INI file in the AXIS section. I guess this could be a little tricker if
the machine has home offset different than zero but not that painful
either.

For example, I have a mill, also a sherline, without limit switches
which I "return home" every time I am done, and then home the axes when
I start.

I have a grinder that's working in the same manner. Since the machine
cannot be moved when it's turned off and also because it's a pretty slow
machine compared to a mill or a lathe I really didn't bother about
installing home and limit switches (It was a pretty basic retrofitting I
must say). But it's working pretty well.

I thought I could use the limit switches also as homing switches.

I'll try that, set them as close to the hard limit as possible.
(However, it seems that the "hard limit" doesn't seem that useful then.)

Surely you can, but you will need to define your soft limits properly
anyways because that's the end of the travel for LinuxCNC in normal
conditions. The hard limits are just a safety measure when the machine is
not homed or I guess in case of a bad configuration of the soft limits.

(tha is why I thought those switches could be used to actually home the
machine, use them as a reference, sort of a "go to" feature...
thinking when the switches get triggered, linuxcnc would "think", ok I
am home now.

As far as I know, it's a normal practice to have them as a safety feature
only. Before the retrofitting the Mazak used them in the same manner. The
only difference was that in some modes of operation the soft limits were
bypassed (I don't know why) and once you triggered any of the limits an
emergency stop was called and the machine had to be homed again to be used.

El vie., 6 nov. 2020 a las 19:50, Phill Carter ()
escribió:

ah, yes, I have not set any soft limits in the new configuration yet.

Also wonder how to do that.

For example, I have a mill, also a sherline, without limit switches

which I "return home" every time I am done, and then home the axes when I
start.

I thought I could use the limit switches also as homing switches.

There is a good diagram of of a shared home/limit switch setup here: <
http://linuxcnc.org/docs/2.8/html/config/ini-homing.html#_shared_limit_home_switch_example_layout
<
http://linuxcnc.org/docs/2.8/html/config/ini-homing.html#_shared_limit_home_switch_example_layout
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Re: [Emc-users] limit switch configuration on lathe in linxcnc (2.7)

Hi Matt,

yes, pretty much. since if I use it as a "homing device", it won't go
past there anyway.

So yes, I think that is what I'd want it to do, use it as home input

On 11/6/20 1:48 PM, Matthew Herd wrote:

I think the question you’re asking is how to use the limit switch as a home
input. On my bridgeport mill, a single limit switch trips on the min and max
limits. I also use this for home. I do this by assigning the same hardware
pin to axis.0.home-sw-in (or axis.1, axis.2, etc) axis.0.neg-lim-sw-in, and
axis.0.pos-lim-sw-in. So you just need to assign the same hardware pin as your
limit switch to home as well as the limit switch input for axis.

Hope this helps!

Matt

On Nov 6, 2020, at 3:23 PM, R C wrote:

Hello Leonardo,

On 11/6/20 1:01 PM, Leonardo Marsaglia wrote:

Hello Ron,

If I understand correctly you are using your limit switches only without
any soft limit (hardware limit). Whenever a limit switch is triggered the
motion will stop immediately and the only way to recover from that is to
turn on the override limits option.

ah, yes, I have not set any soft limits in the new configuration yet. Also
wonder how to do that.

For example, I have a mill, also a sherline, without limit switches which I "return
home" every time I am done, and then home the axes when I start.

I thought I could use the limit switches also as homing switches.

I'll try that, set them as close to the hard limit as possible. (However, it seems that
the "hard limit" doesn't seem that useful then.)

(tha is why I thought those switches could be used to actually home the machine, use them as a
reference, sort of a "go to" feature... thinking when the switches get triggered,
linuxcnc would "think", ok I am home now.

thanks,

Ron

I don't know if understand you right, but you would never want the machine
to trigger a hard limit in normal conditions, you need to set up your soft
limits as close as possible (given your machine's necessities) of the hard
limit.

Leonardo Marsaglia

El vie., 6 nov. 2020 16:03, R C escribió:

Hello,

I am trying to configure the limit switches in linuxcnc, I think I can
use them as home switches too.

The switches get tripped, when teh cross slide is as close to the chuck
as it can be and as close to the user/operator as possible.

I have it setup so that for example the x-axis limit switch will stop
the stepper, but I'd expect to be able to jog in the opposite direction,
which

it doesn't seem to do.

How do I set up the limit switches so that theydo stop the movement of
the axis but still will allow to move an axis in the opposite direction
as the one that triggered the switch?

thanks,

Ron

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Re: [Emc-users] limit switch configuration on lathe in linxcnc (2.7)


Hello Leonardo,

On 11/6/20 1:01 PM, Leonardo Marsaglia wrote:

Hello Ron,

If I understand correctly you are using your limit switches only without
any soft limit (hardware limit). Whenever a limit switch is triggered the
motion will stop immediately and the only way to recover from that is to
turn on the override limits option.


ah,  yes,  I have not set any soft limits in the new configuration yet. 
Also wonder how to do that.



For example, I have a mill, also a sherline, without limit switches 
which I "return home" every time I am done, and then home the axes when 
I start.


I thought I could use the limit switches also as homing switches.


I'll try that, set them as close to the hard limit as possible. 
(However, it seems that the "hard limit" doesn't seem that useful then.)


(tha is why I thought those switches could be used to actually home the 
machine, use them as a reference, sort of a  "go to" feature...  
thinking when the switches get triggered, linuxcnc would "think", ok I 
am home now.


thanks,


Ron



I don't know if understand you right, but you would never want the machine
to trigger a hard limit in normal conditions, you need to set up your soft
limits as close as possible (given your machine's necessities) of the hard
limit.

Leonardo Marsaglia

El vie., 6 nov. 2020 16:03, R C  escribió:


Hello,


I am trying to configure the limit switches in linuxcnc, I think I can
use them as home switches too.


The switches get tripped, when teh cross slide is as close to the  chuck
as it can be and as close to the user/operator as possible.


I have it setup so that for example the x-axis limit switch will stop
the stepper, but I'd expect to be able to jog in the opposite direction,
which

it doesn't seem to do.


How do I set up the limit switches so that theydo stop the movement of
the axis but still will allow to move an axis in the opposite direction
as the one that triggered the switch?


thanks,


Ron





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[Emc-users] limit switch configuration on lathe in linxcnc (2.7)


Hello,


I am trying to configure the limit switches in linuxcnc, I think I can 
use them as home switches too.



The switches get tripped, when teh cross slide is as close to the  chuck 
as it can be and as close to the user/operator as possible.



I have it setup so that for example the x-axis limit switch will stop 
the stepper, but I'd expect to be able to jog in the opposite direction, 
which


it doesn't seem to do.


How do I set up the limit switches so that theydo stop the movement of 
the axis but still will allow to move an axis in the opposite direction 
as the one that triggered the switch?



thanks,


Ron





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Re: [Emc-users] learning how to write a simple canned cycle.

2020-11-05 Thread R C


Hello Andy,


On 11/5/20 4:52 AM, andy pugh wrote:

On Thu, 5 Nov 2020 at 01:05, R C  wrote:


Where could I get it from, and how do I install it in 2.7 ?

Download the ZIP file attached to the first forum post:
https://forum.linuxcnc.org/41-guis/26550-lathe-macros?start=0#34357

(And note that the screenshot shows it running on LinuxCNC 2.6)

You need to drop the Python and NGC files into the config folder, then
integrate the HAL and INI stuff in to your own config.

I downloaded the zip file and followed the instruction in the README.  I 
created a test config and  stuck all that was mentioned in the README in 
the ini directory.


That all seems to work when I start  axis/linuxcnc.


So that was easy to do, oh and looks great btw!   Now I need to learn 
how to use it  :)



thanks!


Ron





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Re: [Emc-users] learning how to write a simple canned cycle.



On 11/4/20 5:53 PM, andy pugh wrote:

On Thu, 5 Nov 2020 at 00:46, R C  wrote:


Currently I am using axis 2.7.15, I would like to try that.  I am
planning on building another machine for this later (with the newest
linuxCNC)
Is it a lot of work to still try the "pretty old" stuff?

The graphical version runs on 2.7 (and probably 2.6)  just look at
that forum thread and decide if you want the touchscreen version or
not.


well,  I don't have a touch screen on the computer that runs linuxcnc, 
so I'd probably want the "non touch screen" version.



When I say "pretty old" the stuff on my web site was LinuxCNC 2.5 and
written in 2011...
In fact I had forgotten it was still there on my website.


Ah, ok,  well..   I am using 2.7.15 right now, as I mentioned,

Where could I get it from, and how do I install it in 2.7 ?


thanks!


Ron




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Re: [Emc-users] learning how to write a simple canned cycle.


Hi Andy,

On 11/4/20 5:31 PM, andy pugh wrote:

On Wed, 4 Nov 2020 at 22:11, Mark Johnsen  wrote:

Andy Pugh (and others) can answer this better than I can, but here's a link
to Andy's website on using the lathe:
http://www.bodgesoc.org/lathe/lathe.html

That's pretty old now. If you have the latest LinuxCNC (2.8) then take
a look in the sample configs, particularly
sim/gmoccapy/lathe_configs/lathe_macros for a ready-to-run config
using these macros:
https://forum.linuxcnc.org/41-guis/26550-lathe-macros?start=150#82743

Currently I am using axis 2.7.15, I would like to try that.  I am 
planning on building another machine for this later (with the newest 
linuxCNC)



Is it a lot of work to still try the "pretty old" stuff?


thanks,


Ron




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Re: [Emc-users] learning how to write a simple canned cycle.

I definitely would like to set up a configuration with Andy's  stuff and 
ply with it.



Andy, if you see this:   What goes where, if I'd set up a new lathe 
configuration as in this page;


http://www.bodgesoc.org/lathe/lathe.html


Ron


On 11/4/20 3:08 PM, Mark Johnsen wrote:

Andy Pugh (and others) can answer this better than I can, but here's a link
to Andy's website on using the lathe:
http://www.bodgesoc.org/lathe/lathe.html

On the above page, he has links to the actual programs, here's one for
turning:
http://www.bodgesoc.org/lathe/turning.ngc

There are more on that first page.  I don't have a linuxCNC lathe, but I'd
use the above examples and then look at the LinuxCNC programming

Here's content about a sherline lathe from the sherline website:
https://sherline.com/wp-content/uploads/2017/08/linuxcnc_help.pdf

Here's a linuxcnc forum discussion that might be useful as well
https://forum.linuxcnc.org/31-cad-cam/487-lathe-programming?lang=fr&start=10

No program, but lathe setup info:
http://linuxcnc.org/docs/html/lathe/lathe-user.html

Good luck,
Mark

On Wed, Nov 4, 2020 at 1:52 PM R C  wrote:


Hello,


I don't know if this is a topic for this list, but trying to learn how
to write a 'simple' canned cycle g-code program

basically to learn how to  get started.


let's say I want to make a simple shaft, stock is a little over 0.25",
and want one half of it to be  0.25" and the other half 3/16"

(Earlier I was looking for an online script or so  that can do that).


Is there a beginners guide/course that walks you through this with
simple examples?  (maybe I should say trivial examples, let's just
assume I know next to nothing about machining.) Are there some examples
to look at, play with?  I have  a small sherline lathe I want to work with.


thanks,


Ron



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[Emc-users] learning how to write a simple canned cycle.


Hello,


I don't know if this is a topic for this list, but trying to learn how 
to write a 'simple' canned cycle g-code program


basically to learn how to  get started.


let's say I want to make a simple shaft, stock is a little over 0.25",  
and want one half of it to be  0.25" and the other half 3/16"


(Earlier I was looking for an online script or so  that can do that).


Is there a beginners guide/course that walks you through this with 
simple examples?  (maybe I should say trivial examples, let's just 
assume I know next to nothing about machining.) Are there some examples 
to look at, play with?  I have  a small sherline lathe I want to work with.



thanks,


Ron



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Re: [Emc-users] PC Wont Boot Debian 10

2020-10-26 Thread R C


Hi John,


I ran into issues like that. different cards might give you different 
issues, some linux-es can be picky like that (especially when you'd have 
to mess with nouveau)


The firmware it is talking about is the linux firmware I think, not the 
firmware on the board.



Did you do the install with the  cli/text interface?  or the graphical 
interface?  It might simply not have seen the integrated graphics card 
when you were installing it.


(there might also be a bios setting, on how the onboard graphics is 
used, it can be disabled too. Also, it might be it isn't a true radeon 
chipset, and didn't get recognized.)




what I did is get a cheap/simple/used graphics card that will work, and 
got rid of the one that didn't play well. In your case that'd mean 
disabling the onboard graphics.



hope that helps


Ron


On 10/26/20 7:15 PM, John Figie wrote:

I forgot to add a subject
John Figie


On Mon, Oct 26, 2020 at 8:18 PM John Figie  wrote:


Dear LinuxCNC users

I started a project about 6 years ago that was delayed because of several
personal issues. I am now ready to begin putting together a computer that I
want to use to control a lathe. I want to install Debian 10 (buster) on my
PC.

I have 2 identical older MBs Asus M5A 78L-M LX. Each has an AMC Sempron 145
processor. I have been running one of these for the last 5 years with
Debian 8 and it seems to work fine. I selected these MBs because they
seemed to have reasonable performance with latency test. I recently
assembled the second MB and decided to install Debian 10 using a USB drive.
The installation completes, installs GRUB and then prompts to reboot.

The GRUB graphical menu screen looks fine.

When the new system boots the last message on the screen is:
[ OK ] Started GNOME Display Manager.
Nothing further happens on the screen.

If i boot with Linux 4.19.0-12 amd64 (recovery mode) then I am able to boot
successfully
At the prompt I can enter the command # journalctl -xb
Looking at the output there is one error displayed:

drm: radeon_pci_probe ERROR radeon kernel modesetting for R600 or later
requires firmware installed.

1) Is this error significant?
2) Do I really need this firmware? I am not using any graphics card -just
the built in graphics.  Gallium 0.4 on AMD RS780 I really don't want to
mess around with trying to flash new firmware on the MB. - but if that is
what it takes I might try to figure out how to do that.

If i swap hard drives with my working Debian 8 system then the new computer
boots normally to the debian 8 GNOME desktop.

If anyone can give me some hints or ideas to try I will appreciate your
help and kindness.

John Figie

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Re: [Emc-users] CAD for parts to make on a lathe

2020-09-23 Thread R C



On 9/23/20 2:05 AM, andy pugh wrote:

On Wed, 23 Sep 2020 at 04:44, R C  wrote:


Wonder if there is something like that for simple things on a lathe.

I already mentioned my lathe macros.

With that and G72 you don't really need CAM. Or even CAD.



What I meant, with the rest of my email, is more  gui style utilities 
like: https://www.intuwiz.com/



for example,  there's this one: https://www.intuwiz.com/round-rectangle.html


but I'll check out the macros



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Re: [Emc-users] CAD for parts to make on a lathe

2020-09-22 Thread R C

well, I got a lot of good information from this list,  also where I was 
"rebuilding" the mill and lathe.


(Phill Carter helped my out A LOT)


There are a bunch of utilities out on the web, that let's you drill 
holes in patterns, make pockets in certain sizes/shapes etc.



Wonder if there is something like that for simple things on a lathe.


Ron


On 9/22/20 9:32 PM, Gene Heskett wrote:

On Tuesday 22 September 2020 15:17:21 R C wrote:


Hi Chris,


well, basically I just want to learn how to use them, by making some
things I actually have a use for. For now on the lathe, I am trying to
make a little shaft for a project.

Why use CNC?  well, because I want to learnhow to use, do lathe work,
using CNC.

Well, I do/did build robots/rovers and such.  and dozens, no, but
maybe 3 shafts that are the same, and if one breaks or so, make
another (the same) one


So really it's about me wanting to learn how to do it, preferably with
something like freecad or so.


I don't make a living CNC machining, I wouldn't be a starving one, but
be dead one by now. I just want to learn how to do it, because I can.


thanks,


Ron

On 9/22/20 11:21 AM, Chris Albertson wrote:

What are you doing with the Lathe that you need CNC?   The answer to
this will determine what software you need.

As soon as you get into operations that are synchronized to the
spindle rotation, like threading you are in need of specialized
lathe-specif CAM software.On the other hand, if you are making a
one-off bushing why use CNC?

One good reason to use CNC on the lathe is for repeatability.  Hand
made parts are only as good as the skill of the operator.  If I
needed to make a few of dozen parts (for maybe an MIT "mini cheetah"
robot) I'd go for CNC so I could be certain the parts would
interchange.

On Mon, Sep 21, 2020 at 5:53 PM R C  wrote:

Hello,


I was away for a while, I saw a lot of replies/suggestions on the
"subject".   I am going to try and see if I can make the part (a
shaft) in freecad, and see what I can do with it.


As for the other software,  well I won't be making money of it,
It's just a hobby,  BUT  I don't really want to set up another
machine or so just for  running something else.


I was thinking,  that since  a lathe (well my lathe)  has a X and Z
axis, if I'd make a part in 'that plane" in freecad,  that it might
be possible to use that?  I saw a suggestion that there might a a
part/plugin in the path workbench.


thanks,

And this list is probably the best on the planet to learn from.


Ron


Cheers, Gene Heskett



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Re: [Emc-users] CAD for parts to make on a lathe

2020-09-22 Thread R C


Hi Chris,


well, basically I just want to learn how to use them, by making some 
things I actually have a use for. For now on the lathe, I am trying to 
make a little shaft for a project.


Why use CNC?  well, because I want to learnhow to use, do lathe work, 
using CNC.


Well, I do/did build robots/rovers and such.  and dozens, no, but maybe 
3 shafts that are the same, and if one breaks or so, make another (the 
same) one



So really it's about me wanting to learn how to do it, preferably with 
something like freecad or so.



I don't make a living CNC machining, I wouldn't be a starving one, but 
be dead one by now. I just want to learn how to do it, because I can.



thanks,


Ron


On 9/22/20 11:21 AM, Chris Albertson wrote:

What are you doing with the Lathe that you need CNC?   The answer to this
will determine what software you need.

As soon as you get into operations that are synchronized to the spindle
rotation, like threading you are in need of specialized lathe-specif CAM
software.On the other hand, if you are making a one-off bushing why use
CNC?

One good reason to use CNC on the lathe is for repeatability.  Hand made
parts are only as good as the skill of the operator.  If I needed to make a
few of dozen parts (for maybe an MIT "mini cheetah" robot) I'd go for CNC
so I could be certain the parts would interchange.

On Mon, Sep 21, 2020 at 5:53 PM R C  wrote:


Hello,


I was away for a while, I saw a lot of replies/suggestions on the
"subject".   I am going to try and see if I can make the part (a shaft)
in freecad, and see what I can do with it.


As for the other software,  well I won't be making money of it, It's
just a hobby,  BUT  I don't really want to set up another machine or so
just for  running something else.


I was thinking,  that since  a lathe (well my lathe)  has a X and Z
axis, if I'd make a part in 'that plane" in freecad,  that it might be
possible to use that?  I saw a suggestion that there might a a
part/plugin in the path workbench.


thanks,


Ron



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Re: [Emc-users] CAD for parts to make on a lathe

2020-09-21 Thread R C


Hello,


I was away for a while, I saw a lot of replies/suggestions on the 
"subject".   I am going to try and see if I can make the part (a shaft) 
in freecad, and see what I can do with it.



As for the other software,  well I won't be making money of it, It's 
just a hobby,  BUT  I don't really want to set up another machine or so 
just for  running something else.



I was thinking,  that since  a lathe (well my lathe)  has a X and Z 
axis, if I'd make a part in 'that plane" in freecad,  that it might be 
possible to use that?  I saw a suggestion that there might a a 
part/plugin in the path workbench.



thanks,


Ron



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Re: [Emc-users] CAD for parts to make on a lathe



On 9/16/20 1:15 PM, Chris Albertson wrote:

No.  I don't know of any CAM software for generating toolpaths for
lathes that runs on Linux.

The best 3D CAD that runs on Linux is  https://www.onshape.com/. But unlike
Fusion360, Onshape does not have the ability to generate toolpaths unless
you get some 3rd party add-in software.

I have two computers here.  An iMac for most things and a Linux based
16-core Xeon PC with nVidia GPU for robotics software development.  Onshape
on the Xeon is 10X faster than Fusion on my older iMac   But I've not
figured out a good way to translate the Onshape models to g-code.

Gene suggests wring g-code by hand but that simply can't be done for
complex parts and even if one could do this there is no "proof" that
g-code I write is the same as what I designed in the CAD system.


I have a few dual cpu xeon machines, with 384Gb ram, but  not ideal to 
run VMs. I use disk trays, so I could just  use one of them to install 
windows on it,  but I hate windows, especially win10




One solution is running a virtual machine on the Linux PC, installing
Windows 10  on that and then Fusion360.   But this requires a rarely
powerful Linux PC.
(At least as a minimum, a 4-core i7 with 16GB RAM and SSD.)

I've been a Linux user (both professional and at home) for a long time and
before Linux existed,  BSD UNIX and Solaris but then one day I wanted to
edit video and process images shot with an SLR.   Adobe is the only game in
town for professional-level media editing unless you consider Apple's Final
Cut Pro X.None of this runs on Linux.


I have been doing *Nix for 30 some odd years, and work in HPC since a 
while..   we do A LOT of image processing, make movies etc


on Linux clusters but that's not a home solution, not even for B. Gates.


On my linux boxes at home I use Gimp, but I am not relly into graphics 
editing though.






On Tue, Sep 15, 2020 at 11:38 PM R C  wrote:


On 9/16/20 12:09 AM, Chris Albertson wrote:

Fusion 360 can generate g-code for mills and lathes.  It's free even for
commercial use until you make $50K using it.

Fusion is a little bit like Freecad but is more complete and better
supported as you would expect of a product from Autodesk.


I have heard about that one.   does it run on Linux too?




On Tue, Sep 15, 2020 at 9:39 PM R C  wrote:


Hello,


I have been using freecad for designing parts, and then milling them on
a sherline mill, getting the hang of that a little bit.


I have a lathe too, that works with CNC linux, but noticed heard, that
you can't really  make parts, or g-codes, with it for a lathe.


What wold be a good choice for designing, simple, parts for a lathe,
that will create g-code for it?


thanks,


Ron



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Re: [Emc-users] CAD for parts to make on a lathe

well, I was thinking, this morning  that if you can make a part by 
rotating it, in freecad, you can also extrude it a bit and then create 
code for a mill.


If the steps/overlap would be small, then  one would end up with 
something that can be used on a mill, with some adaptations/translations?



Of course ..  that idea probably  is asking for trouble.



On 9/16/20 1:15 PM, Chris Albertson wrote:

No.  I don't know of any CAM software for generating toolpaths for
lathes that runs on Linux.

The best 3D CAD that runs on Linux is  https://www.onshape.com/. But unlike
Fusion360, Onshape does not have the ability to generate toolpaths unless
you get some 3rd party add-in software.

I have two computers here.  An iMac for most things and a Linux based
16-core Xeon PC with nVidia GPU for robotics software development.  Onshape
on the Xeon is 10X faster than Fusion on my older iMac   But I've not
figured out a good way to translate the Onshape models to g-code.

Gene suggests wring g-code by hand but that simply can't be done for
complex parts and even if one could do this there is no "proof" that
g-code I write is the same as what I designed in the CAD system.

One solution is running a virtual machine on the Linux PC, installing
Windows 10  on that and then Fusion360.   But this requires a rarely
powerful Linux PC.
(At least as a minimum, a 4-core i7 with 16GB RAM and SSD.)

I've been a Linux user (both professional and at home) for a long time and
before Linux existed,  BSD UNIX and Solaris but then one day I wanted to
edit video and process images shot with an SLR.   Adobe is the only game in
town for professional-level media editing unless you consider Apple's Final
Cut Pro X.None of this runs on Linux.


On Tue, Sep 15, 2020 at 11:38 PM R C  wrote:


On 9/16/20 12:09 AM, Chris Albertson wrote:

Fusion 360 can generate g-code for mills and lathes.  It's free even for
commercial use until you make $50K using it.

Fusion is a little bit like Freecad but is more complete and better
supported as you would expect of a product from Autodesk.


I have heard about that one.   does it run on Linux too?




On Tue, Sep 15, 2020 at 9:39 PM R C  wrote:


Hello,


I have been using freecad for designing parts, and then milling them on
a sherline mill, getting the hang of that a little bit.


I have a lathe too, that works with CNC linux, but noticed heard, that
you can't really  make parts, or g-codes, with it for a lathe.


What wold be a good choice for designing, simple, parts for a lathe,
that will create g-code for it?


thanks,


Ron



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Re: [Emc-users] CAD for parts to make on a lathe



On 9/16/20 12:26 PM, Gene Heskett wrote:

On Wednesday 16 September 2020 10:02:25 R C wrote:


yesterday, I noticed some electronics in my little lathe fried/died,
after I fix that I'll try to use it.


Everybody knows this stuff runs on smoke & mirrors, so what did you do to
break the mirror & let the smoke out?

btw:  I think that the high summer temperatures, it either being humid, 
or with AC dry and static didn't help much either, that


and some  thunderstorms in the mix .

up here where I live, we constantly have cooling issues with computing 
equipment etc, (there's 30% less air than at sea level), there


were several 'cooling incidents' around that time, where I work




On 9/16/20 7:45 AM, andy pugh wrote:

On Wed, 16 Sep 2020 at 14:45, R C  wrote:

that sounds like something I had in mind, well, either that or just
design a part with "something"

You can try it out, there is a gmoccapy simulator sample package
using it. (Which, thinking about it, means that the base files must
be in LinuxCNC now)

Which further means that I ought to fix the bug that one of the
feed-per-rev boxes doesn't work.

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Cheers, Gene Heskett



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Re: [Emc-users] CAD for parts to make on a lathe



On 9/16/20 12:26 PM, Gene Heskett wrote:

On Wednesday 16 September 2020 10:02:25 R C wrote:


yesterday, I noticed some electronics in my little lathe fried/died,
after I fix that I'll try to use it.


Everybody knows this stuff runs on smoke & mirrors, so what did you do to
break the mirror & let the smoke out?


Hahaha ...

well,  they are sherline machines, in Paxton/Patterson enclosures, and I 
took out that optistep stuff, well, pretty much took


everything out except the motor controller.

Then I  build everything over, experimentally, with some cheap chinese 
components, like voltage regulators etc, and it seemed to be working


and decided I redo it the right way later.


And apparently yesterday it was later  ...   *lol*




On 9/16/20 7:45 AM, andy pugh wrote:

On Wed, 16 Sep 2020 at 14:45, R C  wrote:

that sounds like something I had in mind, well, either that or just
design a part with "something"

You can try it out, there is a gmoccapy simulator sample package
using it. (Which, thinking about it, means that the base files must
be in LinuxCNC now)

Which further means that I ought to fix the bug that one of the
feed-per-rev boxes doesn't work.

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Cheers, Gene Heskett



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Re: [Emc-users] CAD for parts to make on a lathe

yesterday, I noticed some electronics in my little lathe fried/died, 
after I fix that I'll try to use it.




On 9/16/20 7:45 AM, andy pugh wrote:

On Wed, 16 Sep 2020 at 14:45, R C  wrote:


that sounds like something I had in mind, well, either that or just
design a part with "something"

You can try it out, there is a gmoccapy simulator sample package using it.
(Which, thinking about it, means that the base files must be in LinuxCNC now)

Which further means that I ought to fix the bug that one of the
feed-per-rev boxes doesn't work.




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Re: [Emc-users] CAD for parts to make on a lathe

I actually read something about how to do that, but one would need a 
plugin for the path workbench, and read is was not that reliable?


I did play with rotating parts etc in freecad


On 9/16/20 4:42 AM, N wrote:

Hello,


I have been using freecad for designing parts, and then milling them on
a sherline mill, getting the hang of that a little bit.


I have a lathe too, that works with CNC linux, but noticed heard, that
you can't really  make parts, or g-codes, with it for a lathe.

Also used Freecad a little bit. Suspect rotating a sketch is a good or very 
good method to draw parts for a lathe. Do know anything about how CAM, the path 
workbench will work a lathe but should be simple to try.

As someone pointed out Fusion 360 might be better but CAD software usually also 
tend to be rather expensive.


Regards Nicklas Karlsson


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Re: [Emc-users] CAD for parts to make on a lathe

Hi Andy,

that sounds like something I had in mind, well, either that or just
design a part with "something"

Things I am planning on doing on a lathe are rather simple, I want to
make a little shaft with different

diameters in some places.

On 9/16/20 2:34 AM, andy pugh wrote:

On Wed, 16 Sep 2020 at 07:38, R C wrote:

Fusion is a little bit like Freecad but ...

I have heard about that one. does it run on Linux too?

No. Which looks like a deliberate choice as it _does_ run natively
(and nicely) on OSX.

It makes decent G-code, but I rarely bother.

For almost everything I make on the lathe I work _at_ the lathe and use:
https://forum.linuxcnc.org/41-guis/26550-lathe-macros?start=0
Which is a lot like using a manual lathe, but with a hyper-capable power feed.

For example, making an ER20 collet last night. I used "face" on the
end of the bar. Drilled a hole with the tailstock, then used a "bore"
cycle to make a counterbore for the (special) nut, then another boring
cycle with an 8 degree taper for the collet socket, followed by a
threading cycle to finish it off.

Also, the master branch contains the G70 / 71 / 72 lathe cycles:
http://linuxcnc.org/docs/devel/html/gcode/g-code.html#gcode:g70

Basically you define the profile with G1, G2, G3 lines and arcs in a
subroutine and LinuxCNC makes that shape.

The documentation for the actual implementation is rather poor. There
is better documentation for a _different_ implementation with many of
the letters allocated to different functions here:
https://github.com/LinuxCNC/linuxcnc/blob/andypugh/g71type2remap/docs/src/gcode/g-code.txt#g71-lathe-roughing-cycle-turning

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Re: [Emc-users] CAD for parts to make on a lathe

2020-09-15 Thread R C



On 9/16/20 12:09 AM, Chris Albertson wrote:

Fusion 360 can generate g-code for mills and lathes.  It's free even for
commercial use until you make $50K using it.

Fusion is a little bit like Freecad but is more complete and better
supported as you would expect of a product from Autodesk.



I have heard about that one.   does it run on Linux too?





On Tue, Sep 15, 2020 at 9:39 PM R C  wrote:


Hello,


I have been using freecad for designing parts, and then milling them on
a sherline mill, getting the hang of that a little bit.


I have a lathe too, that works with CNC linux, but noticed heard, that
you can't really  make parts, or g-codes, with it for a lathe.


What wold be a good choice for designing, simple, parts for a lathe,
that will create g-code for it?


thanks,


Ron



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[Emc-users] CAD for parts to make on a lathe

2020-09-15 Thread R C


Hello,


I have been using freecad for designing parts, and then milling them on 
a sherline mill, getting the hang of that a little bit.



I have a lathe too, that works with CNC linux, but noticed heard, that  
you can't really  make parts, or g-codes, with it for a lathe.



What wold be a good choice for designing, simple, parts for a lathe, 
that will create g-code for it?



thanks,


Ron



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Re: [Emc-users] cnc axis "Touch Off"

2020-09-11 Thread R C

yes, I use "Touch Off".  the other one is typically grayed out. I am 
pretty sure because there is no tool selected yet.



When I make parts, I typically use one tool per g-code, I try to keep it 
simple.



The CNC machines I have are pretty simple,  they are Sherline machines, 
in a Paxton/Patterson enclosure,  (I have replaced all the  steppers and 
stepper controllers, power supplies etc replaced with stuff commonly 
used. And there are no fancy things like tool changers or anything like 
that to begin with.



Ron



On 9/11/20 10:09 AM, N wrote:

There are two buttons "Touch Off" and "Tool Touch Off". You always use the same?


Jon,

I wrote a bunch of wizards for my mill and my lathe. I use one coordinate 
system for the origin of the main part and a different origin for each each 
wizard as it is called so that the wizard works with respect to the/an origin. 
It makes the math in the wizard much simpler, especially when you are doing 
something like rotating a rectangle.

Alan


From: Jon Elson 
Subject: Re: [Emc-users] cnc axis "Touch Off"
Date: September 10, 2020 at 9:04:23 PM CDT
To: "Enhanced Machine Controller (EMC)" 


On 09/10/2020 08:28 PM, R C wrote:

I figured out the "touch off", and that it 'works' the same as homing, 
functionally.


I wondered what all the different coordinate systems are for, their differnces.

(I know what a coordinat system is, mathematician here.)

This allows you to set up an offset from a main coordinate system, for instance 
if you have several identical features to be machined on a part, one hunk of 
G-code could machine each part and then set up the offset to machine the next 
instance.

It can also be used if you have several parts mounted in a fixture, one coord 
system for each part.

Jon


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Re: [Emc-users] cnc axis "Touch Off"

2020-09-11 Thread R C

well, I am comfortable with matrix algebra, but it's probably easier, 
more practical, to just do that part in freecad or so, and use a 
separate g code file for that.


I was just wondering  what these different coordinate systems are, what 
they are used for.



On 9/11/20 9:26 AM, dave engvall wrote:
IIRC some controls have a switch to do this.  Also I think you can 
flip the sign of one axis and get a mirror image but the sense of the 
cut (climb/conventional) also flips so unless your machine is pretty 
tight dimensions may also shift. I've always done this the hard way by 
going back to the CAM. My brain is pretty well fried but I think a bit 
of matrix algebra would do this for you.


Dave

On 9/11/20 6:43 AM, R C wrote:

Hello Andy,

That is interesting, I should learn more about these coordinate 
systems.  From a math/geometry perspective  there nothing that could 
keep you from


translating, rotating (and even more weird transformations)  a 
geometry into a custom one. However in an implementation, of course, 
you'd have to have a spot somewhere between the definition of an 
object (g code if you will) and where the machine/tool actually 
moves.  In some, not CC related, simulations, that's actually done/used.



there probably is a list of what these  coordinatesystems actually do?

(Now I am wondering, if I make a part, is there a coordinate system, 
that would turn out the mirror image that part?)



Ron





On 9/11/20 1:54 AM, andy pugh wrote:

On Fri, 11 Sep 2020 at 05:22, R C  wrote:


It sounds like the coordinate systems in essence are the same,  they
just have a different origin, for all the other parts, it's just the
same thing, just translated and/or rotated for another part?

Yes, and there is also only rotation about the  axis supported.
(I did just find myself wondering if you could put a set of direction
cosines in UVW but then decided that there probably isn't much call
for that.)

http://linuxcnc.org/docs/2.8/html/gcode/coordinates.html




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Re: [Emc-users] cnc axis "Touch Off"

2020-09-11 Thread R C


Hello Andy,

That is interesting, I should learn more about these coordinate 
systems.  From a math/geometry perspective  there nothing that could 
keep you from


translating, rotating (and even more weird transformations)  a geometry 
into a custom one. However in an implementation, of course, you'd have 
to have a spot somewhere between the definition of an object (g code if 
you will) and where the machine/tool actually moves.  In some, not CC 
related, simulations, that's actually done/used.



there probably is a list of what these  coordinatesystems actually do?

(Now I am wondering, if I make a part, is there a coordinate system, 
that would turn out the mirror image that part?)



Ron





On 9/11/20 1:54 AM, andy pugh wrote:

On Fri, 11 Sep 2020 at 05:22, R C  wrote:


It sounds like the coordinate systems in essence are the same,  they
just have a different origin, for all the other parts,   it's just the
same thing, just translated and/or rotated for another part?

Yes, and there is also only rotation about the  axis supported.
(I did just find myself wondering if you could put a set of direction
cosines in UVW but then decided that there probably isn't much call
for that.)

http://linuxcnc.org/docs/2.8/html/gcode/coordinates.html




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Re: [Emc-users] cnc axis "Touch Off"



ah ok,

It sounds like the coordinate systems in essence are the same,  they 
just have a different origin, for all the other parts,   it's just the 
same thing, just translated and/or rotated for another part?



Ron



On 9/10/20 8:04 PM, Jon Elson wrote:

On 09/10/2020 08:28 PM, R C wrote:
I figured out the "touch off", and that it 'works' the same as 
homing, functionally.



I wondered what all the different coordinate systems are for, their 
differnces.


(I know what a coordinat system is, mathematician here.)
This allows you to set up an offset from a main coordinate system, for 
instance if you have several identical features to be machined on a 
part, one hunk of G-code could machine each part and then set up the 
offset to machine the next instance.


It can also be used if you have several parts mounted in a fixture, 
one coord system for each part.


Jon


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Re: [Emc-users] cnc axis "Touch Off"

I figured out the "touch off", and that it 'works' the same as homing, 
functionally.



I wondered what all the different coordinate systems are for, their 
differnces.


(I know what a coordinat system is, mathematician here.)


Ron



On 9/10/20 6:53 PM, Jon Elson wrote:

On 09/10/2020 05:59 PM, R C wrote:

I was just playing with it a bit,


I have the idea, that , like homing is done per axis, "touching Off" 
is done per axis too?
Yes, you should be able to select the axis that is to have its offset 
changed and then enter what that coordinate should be set to.  (You 
can also select the workpiece coordinate system on that dialog box.)


Jon


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Re: [Emc-users] cnc axis "Touch Off"




On 9/10/20 5:49 PM, Gene Heskett wrote:

On Thursday 10 September 2020 18:50:03 jrmitchellj wrote:


On a Mill setup, touch-off only affects the Z axis.  You will need to
find your X0, and Y0 positions.  I use the end key to bring up the
dialog and set the offset.

--J. Ray Mitchell Jr.
jrmitche...@gmail.com


It works for all 4 configured axis's here.


I assume you still have to do each axis separate, that's what I have to 
do it seems.






"Good enough is the enemy of excellence"author unknown

On Thu, Sep 10, 2020 at 2:51 PM R C  wrote:

Hello,


this is probably a rookie question, but sometime when I do a "Touch
Off",  the Z-position indeed becomes 0,  but the X and Y are not.
Then in teh axis program, it will still go to the "first" spot where
it needs to start milling, and in the  drawing it fllows the correct
lines/pattern,  but since the tuch off wasn't in the origin (0, 0,
0) on the actual workpiece/part the machining is off (and
consequently goes out of the material, and starts milling air at
some point.


I am wondering why that happens?   Is that a mistake I sometimes
make in Freecad, or is that something I do wrong touching off? (I am
fairly sure it is not a bug).


How can I make sure that I am actually touching off at (0, 0, 0) ?


thanks,


Ron

(sorry if I have some terminology incorrect, but you know ... rookie
here.)



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Cheers, Gene Heskett



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Re: [Emc-users] cnc axis "Touch Off"

yup,  that's why I noticed too.  I thought "touch off" would be more 
like "this is (0, 0, 0)"  and just hit that button once...


I guess I got lucky a few times.



On 9/10/20 5:28 PM, Dave Matthews wrote:

That is how I do it.  There are three radio buttons, one for each axis.  It
defaults to the last axis moved which is usually z.

Dave

On Thu, Sep 10, 2020, 19:01 R C  wrote:


I was just playing with it a bit,


I have the idea, that , like homing is done per axis, "touching Off" is
done per axis too?



thanks,


Ron





On 9/10/20 4:50 PM, jrmitchellj wrote:

On a Mill setup, touch-off only affects the Z axis.  You will need to

find

your X0, and Y0 positions.  I use the end key to bring up the dialog and
set the offset.

--J. Ray Mitchell Jr.
jrmitche...@gmail.com



"Good enough is the enemy of excellence"author unknown


On Thu, Sep 10, 2020 at 2:51 PM R C  wrote:


Hello,


this is probably a rookie question, but sometime when I do a "Touch
Off",  the Z-position indeed becomes 0,  but the X and Y are not.   Then
in teh axis program, it will still go to the "first" spot where it needs
to start milling, and in the  drawing it fllows the correct
lines/pattern,  but since the tuch off wasn't in the origin (0, 0, 0) on
the actual workpiece/part the machining is off (and consequently goes
out of the material, and starts milling air at some point.


I am wondering why that happens?   Is that a mistake I sometimes make in
Freecad, or is that something I do wrong touching off? (I am fairly sure
it is not a bug).


How can I make sure that I am actually touching off at (0, 0, 0) ?


thanks,


Ron

(sorry if I have some terminology incorrect, but you know ... rookie

here.)



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Re: [Emc-users] cnc axis "Touch Off"


I was just playing with it a bit,


I have the idea, that , like homing is done per axis, "touching Off" is 
done per axis too?




thanks,


Ron





On 9/10/20 4:50 PM, jrmitchellj wrote:

On a Mill setup, touch-off only affects the Z axis.  You will need to find
your X0, and Y0 positions.  I use the end key to bring up the dialog and
set the offset.

--J. Ray Mitchell Jr.
jrmitche...@gmail.com



"Good enough is the enemy of excellence"author unknown


On Thu, Sep 10, 2020 at 2:51 PM R C  wrote:


Hello,


this is probably a rookie question, but sometime when I do a "Touch
Off",  the Z-position indeed becomes 0,  but the X and Y are not.   Then
in teh axis program, it will still go to the "first" spot where it needs
to start milling, and in the  drawing it fllows the correct
lines/pattern,  but since the tuch off wasn't in the origin (0, 0, 0) on
the actual workpiece/part the machining is off (and consequently goes
out of the material, and starts milling air at some point.


I am wondering why that happens?   Is that a mistake I sometimes make in
Freecad, or is that something I do wrong touching off? (I am fairly sure
it is not a bug).


How can I make sure that I am actually touching off at (0, 0, 0) ?


thanks,


Ron

(sorry if I have some terminology incorrect, but you know ... rookie here.)



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Re: [Emc-users] cnc axis "Touch Off"


Hello,


this is probably a rookie question, but sometime when I do a "Touch 
Off",  the Z-position indeed becomes 0,  but the X and Y are not.   Then 
in teh axis program, it will still go to the "first" spot where it needs 
to start milling, and in the  drawing it fllows the correct 
lines/pattern,  but since the tuch off wasn't in the origin (0, 0, 0) on 
the actual workpiece/part the machining is off (and consequently goes 
out of the material, and starts milling air at some point.



I am wondering why that happens?   Is that a mistake I sometimes make in 
Freecad, or is that something I do wrong touching off? (I am fairly sure 
it is not a bug).



How can I make sure that I am actually touching off at (0, 0, 0) ?


thanks,


Ron

(sorry if I have some terminology incorrect, but you know ... rookie here.)



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Re: [Emc-users] LinuxCNC legacy or future

2020-09-08 Thread R C

well, I havebeen coding for a good long while,  I wouldn't know the 
first thing about CNC Linux, but


would be interested in doing something with sensors, or those quadrature 
encoders...  BUT  it's pretty  hard to find any info


about details like that, and how it would fit in (for example,  I assume 
you can't 'steal' too many cycles.)



But I agree, there are tons of people that work on it,  there are a lot 
more that work with it,  so just saying, create your own fork/branch is


saying the same as "no, go away..."  besides,  what is the point of 
having dozens of distros?



I like it, I like the work that's done, I  don't know much about CNC 
machining (that is an overstatement actually), and it probably does a 
lot more then I ever use, or have the time to understand.



so..  uhm..   thanks for those that do the work...


Ron


On 9/8/20 7:38 PM, andy pugh wrote:

On Mon, 7 Sep 2020 at 22:31, Rafael Skodlar  wrote:


IMO it's extremely bad to attack those who come up with "it would be
nice to have this or that" in existing product. Saying, "it's open
source, go fork and write your own code" is plain STUPID! We are not all
programmers! [1]

The problem is that not enough of us are programmers. ( I am not a programmer )

When folk say "you want it, you code it" this isn't a rejection of the
idea, it is just that they know that they can't do it.

The Machinekit fork wasn't a high point of the LinuxCNC story. But MAH
wanted to re-work NML to use a 0MQ as he was keen to make the GUI /
Realtime split that some are asking for. He took more than a whole
year off work to make that happen. It didn't happen (in LinuxCNC _or_
Machinekit as far as I know)

An analysis of the 2.8 release:

LinuxCNC contains  2,294,176 lines of code. 55% of those were touched
during 2.8 development.




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Re: [Emc-users] Error with ISO image

2020-09-07 Thread R C

I had some issues with it too.  Somehow  the installer messes up setting 
the boot dev in grub (or whatever it is called in debian.)


The installer goes haywire if there are more then 1 drives, at least 
that is what I noticed.


(don't know if that's your issue, it also sees activated SAS ports as 
drives.)



you can either (in the BIOS)  turn the drives you don't need, for now, 
"off" so that there's only one hard drive (and a USB stick/drive or so.)



OR  after the install,  boot with the install media, in rescue mode,  
mount the drive you tried to install on and fix the grub.



I had those issues on different machines that I tried,  what happens, 
for example,  is you're trying to install on /dev/sda, but  you have a 
few other drives..  the installer  counts them and then thinks the one 
after last is the boot device.   for example if you have 4 drives,  it 
sticks /dev/sde in there. When booting it thinks the boot partition is 
on another device.


I tried it with "regular" debian too,  'their' installer is broken,  
it's not a linux-CNC issue.



Ron



On 9/7/20 3:36 PM, andy pugh wrote:

On Sun, 6 Sep 2020 at 06:35, Viesturs Lācis  wrote:


I downloaded ISO image with 2.7.14 version and I cannot make it to
work.

Can you try http://www.linuxcnc.org/iso/linuxcnc-2.8.0-buster.iso ?

It has just worked for me on two machines (one an od D510MO board, and
one a brand-new machine with a pre-installed WIndows10 ad UEFI.

(and if it still fails at the cdrom stage, unplugging and replugging
the USB then pressing "continue" is alleged to work. But I really
would prefer it to work without that.)




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Re: [Emc-users] Interesting GUI

2020-09-04 Thread R C

I agree there,  CNC Linux is pretty cool, it can do a lot more than I 
can ever learn about it..  and it's free...



you can't complain about free...   especially if a ton of people like it..



On 9/4/20 6:16 PM, Phill Carter wrote:



On 5 Sep 2020, at 4:53 am, Mark Wendt  wrote:

On Fri, Sep 4, 2020 at 1:05 PM Chris Albertson mailto:albertson.ch...@gmail.com>>
wrote:


On Fri, Sep 4, 2020 at 9:50 AM Mark Wendt  wrote:


On Fri, Sep 4, 2020 at 12:41 PM Chris Albertson <

albertson.ch...@gmail.com

wrote

...So, to make LinuxCNC nearly universal, hide it inside a product that

is

slick and easy to install and use.  No one should have to look at HAL

files

or know it runs on Linux.  They can learn, but if learning is required

it

will always remain a niche product.


Great stuff!  So, when are you going to get started on this project?


I wrote that to show why it will never happen.   But also to make a point
that there does exist a pattern in the way complex niche products become
mainstream.   Usually, another layer is built around it.PCs were kind
of rare until Windows covered over the DOS command line.


And I wrote that because of all the pie in the sky whining about what this
set of programs needs to be, and no one stepping up to make the effort to
do something like that.  The vast majority of LinuxCNC users are quite
happy with what our developers write for us to use.  It's open source
software.  If you don't like the direction LinuxCNC is going, fork off,
write your own version so that it does what you perceive to be the next
golden goose, thump your chest and tell the world you now have the latest
and best CNC machine controller.

Otherwise, lets stop flogging the deceased equine.  Unless all you guys
that want this kind of stuff take the bull by the horns and start writing
the code for it, it ain't gonna happen.

Mark

My thoughts exactly Mark, this constant whining wears thin…

Cheers, Phill.
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Re: [Emc-users] off topic: pwm with a stepper driver/motor


Hi Chris,

On 7/14/20 12:10 PM, Chris Albertson wrote:

On Tue, Jul 14, 2020 at 10:50 AM John Dammeyer 
wrote:


https://youtu.be/tlMTksuOuZQ


Were you using LinuxCNC for this?  Or did you write your own control
software?


This was done with Linux CNC.   However, The purpose of me owning a mill is
for robotics.  I have not yet figured how to use LCNC for robot projects so
in those cases I do my own low-level motion control, typically using STM32
and an RTOS.


Same here,  I am using the same drivers and motors in my Sherline CNC 
machines...   BUT  trying to make my own interface fr the telescope.


(would be interesting if there could be a telescope "option"    I don't 
think a telescope is probably not that different...    but outside the 
scpe,  since it is not a CNC machine.





The video is not meant to stand alone.  It will be part of a web site that
has other videos and some text and photos.  But it does show how motors
must be ramped up and down.




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Re: [Emc-users] off topic: pwm with a stepper driver/motor

On 7/14/20 11:48 AM, John Dammeyer wrote:

-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com]
Sent: July-14-20 2:49 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] off topic: pwm with a stepper driver/motor

Gene is correct when he wrote the precision might be off when
micro-stepping.

Yes.  Micro-stepping is only for harmonic reduction.  You cannot rely on 
positioning with micro-stepping. It can take 3 or 4 micro-steps to even start 
moving to overcome static friction.

Motors are mechanically built for 1.8 degree steps so that is likely to be
accurate but half steps depend on the driver.

Half steps rely on only one coil energized so you lose half the torque.  For 
static motion that may well be enough depending on the size of the motor and 
the load.

But what I wanted to add is that when you read the speed vs. torque curve
it is for FULL steps.  The amount of holding torque is reduced with
microsteps.   It makes sense too, full steps use full current that is
switched between coils just 100% on or 100% off.   With microsteps one
coild gets perhaps 3/8 of full current and the other gets something like
5/8.  So the current is overall reduced.

70.7% is the number you are looking for.

In any case, run the motors at a step rate that causes them to run smoothly
without actually stepping.  You want to see continuous motion.

BTW I'm using a DM542, the same driver you have on this vertical axis test
(link below).   It has enough power even when doing 1/2 steps to move a 35
pound chunk of steel up and up at a decent rate of speed.   machine is
obviously not balanced like a telescope  The DM542 is set for only 2.0 amps
so it is not running at full power. SO you will be fine even with the
reduced torque.

This is the first time this axis ran.  Just some jogs up and down.
https://youtu.be/tlMTksuOuZQ

Were you using LinuxCNC for this?  Or did you write your own control software?

Actually,  both.   I have a Sherline mill and lathe that I am running 
with lnux cnc  and...  the same motors and stepper drivers.

The telescope will have the same drivers and stepper motors, BUT  
writing my own interface to try and control them,...  well that before I 
try to hook it up to Stellarium directly.

John Dammeyer

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Re: [Emc-users] off topic: pwm with a stepper driver/motor


Hi Chris,


for the go to part I am not "too worried"about that possibly not being 
too smooth, of course it is the goal to do that, but


the point there is to get there.

The equatorial tracking indeed needs to be as smooth as possible.  With 
the hearing I have I think I can run the stepper motors smooth


without having to do any micro stepping.


thanks,


Ron



On 7/14/20 3:49 AM, Chris Albertson wrote:

Gene is correct when he wrote the precision might be off when
micro-stepping.

Motors are mechanically built for 1.8 degree steps so that is likely to be
accurate but half steps depend on the driver.

But what I wanted to add is that when you read the speed vs. torque curve
it is for FULL steps.  The amount of holding torque is reduced with
microsteps.   It makes sense too, full steps use full current that is
switched between coils just 100% on or 100% off.   With microsteps one
coild gets perhaps 3/8 of full current and the other gets something like
5/8.  So the current is overall reduced.

In any case, run the motors at a step rate that causes them to run smoothly
without actually stepping.  You want to see continuous motion.

BTW I'm using a DM542, the same driver you have on this vertical axis test
(link below).   It has enough power even when doing 1/2 steps to move a 35
pound chunk of steel up and up at a decent rate of speed.   machine is
obviously not balanced like a telescope  The DM542 is set for only 2.0 amps
so it is not running at full power. SO you will be fine even with the
reduced torque.


This is the first time this axis ran.  Just some jogs up and down.   But
listen to the motor, you can't start and stop these stepper motors
instantly the velocity ramps up and down.  In fact this rate of change is
as fast as I can go with this setup and the DM542's  2.0 amp current limit.
   If you do a fast slew to a target, you need to ramp up the speed then
slow down and hit the mark and then pick up the star tracking rate.  That
second loop controls the speed and the rate of change of that speed.
Software was to plan the motion in advance so that it start to slow soon
enough not to over shoot
https://youtu.be/tlMTksuOuZQ

On Mon, Jul 13, 2020 at 11:51 PM Gene Heskett  wrote:


The driver tech-sheet  basically says it can do pretty all it's
available micro stepping with a 1.8 degree stepper motor, I wonder if
that is really true.


In theory yes, in practice, no. There is resistor tolerances and all
sorts of errors that can creep into a motor being held by the relative
balance of the currents thru 2 sets of coils.





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Re: [Emc-users] off topic: pwm with a stepper driver/motor


Hello Gene,

On 7/14/20 12:49 AM, Gene Heskett wrote:

On Monday 13 July 2020 22:44:37 R C wrote:


well,  I can calculate what the speed needs to be, also I can actually
"observe" it too..  by pointing the  telescope at a star and see how
much the deviation is.  I have encoder to check the actual speed of a
shaft.

I found some information in a manual/tech-sheet that comes with the
drivers, so I am trying to figure out what the best stepping rate is
and what the best way of actually sending pulses to the stepper-driver
is.

I wrote some c-code that runs the motors in pthreads, I just want to
know what the best way is.  pulse lengths, pause/gap length etc.
(basically the best way to use a dm542  (all those steppers are sorta
the same I understand)

The driver tech-sheet  basically says it can do pretty all it's
available micro stepping with a 1.8 degree stepper motor, I wonder if
that is really true.


In theory yes, in practice, no. There is resistor tolerances and all
sorts of errors that can creep into a motor being held by the relative
balance of the currents thru 2 sets of coils. So while a full switch
will move it 1.8 dgreees, or 1.2 with the newer 3 phase models, between
magnetics and parts tolerances, half current in each coil might be out
of balance as much as 10% in off the shelf stuff. Sometimes its fairly
obvious, I have a dm860 driver that when moving a 1600 oz/in motor at
a /8 divisor, moves 7 steps rather noisily, and the 8th step cannot be
seen or heard.  Worked fine on my mill as long as I stayed below 26 ipm.
But thats too slow for rigid tapping. A 960oz/in and ac powered driver
was subbed, moves that heavy head at nearly 100 ipm, dead smooth.

Right, but I can probably get it close by calculating, and then adjust  
for "tolerances" and


feedback from the encoders I have.


I also have a dm860, using it in a Sherline mill where I put a bigger 
stepper motor on the Z-axis.


(I replaced all stepper motors and drivers in a Sherline mill and lathe 
(they came in a Paxton/Patterson enclosure).



thanks,


Ron





Ron

On 7/13/20 8:35 PM, Chris Albertson wrote:

A fast control loop that drives each motor at a given speed and a
second slower control loop that figures out what that speed should
be.   The second loop typically uses "PID" even if only in fact the
"P" is used.

That can be used to drive any number of motors all at their correct
speeds.

On Mon, Jul 13, 2020 at 7:28 PM R C  wrote:

Interesting,


but I already have the motors,  and  the gears are on their way.
What I was really looking for is how to drive the stepper-drivers,
he DM542 series ones.


Ron

On 7/13/20 7:53 PM, cogoman via Emc-users wrote:

I recently discovered geared stepper motors.

http://www.zyltech.com/nema-17-stepper-motor-geared-planetary-gearb
ox-1-7-a-3-1-nm-435-ozin/


I've been happy with zyltech in the past.  I bought one of these
for evluation, but the specs seem to be great for CNC. Low enough
current to work with a stepstick, High enough torque for a fairly
powerful machine, and less than 4 mH inductance should let it step
pretty fast.

5.18:1 gear ratio should reduce that 4 meter spur gear, but the
link below has higher gear ratios that would reduce that spur gear
greatly! Backlash could be a problem for CNC, but if you are only
going one way, the less precision gearboxes might be fine.

https://www.omc-stepperonline.com/geared-stepper-motor/?sort=p.pric
e&order=ASC


Once you visit the stepperonline web page you know as much about
them as I do, but their offerings might be just right for your
application.

On 7/9/20 2:23 PM, R C wrote:

Hello,

this is (probably) off topic, been seen that happen.  If it is
please ignore it.


I am building a "motorized"  telescope mount (dobsonian) with
what is called an equatorial platform, it has 3 axis which I am
going to drive with stepper motors.


The stepper motors I use with a stepper driver, those common
DM542 ones, the stepper motors themselves are 2A and 1.8 degrees
per step.


What I want to accomplish with the equatorial platform)  (it
compensates for the rotation of the earth) is that,  the start
and end position accuracy is not that important,  smooth and
constant/consistent movement is.  for the azimuth/altitude
precision is not a really big deal, but you'd want to move these
2 axis somewhat swift.


So there are a few factors to decide.


I probably want micro stepping,  what settings on the driver for
pulses per rev, is best to use (or is that just trial and error?)


As with PWM itself, I am probably just not too familiar with it.
 From what I understand, the voltage I use for the motors
determines how fast I can go (I am going to use a 48V switching
power supply).


as for PWM,  I can of course  change the length of the pulse
itself and, independently, change the time between two pulses.
What is the relation ship there?  WHat does a longer  width of
the pulse itself do?  an

Re: [Emc-users] off topic: pwm with a stepper driver/motor


Hello Chris,


On 7/14/20 12:31 AM, Chris Albertson wrote:

On Mon, Jul 13, 2020 at 7:28 PM R C  wrote:


Interesting,


but I already have the motors,  and  the gears are on their way.   What
I was really looking for is how to drive the stepper-drivers, he DM542
series ones.



Do you have the user manual for the DM542?   If not look at the top top
half of page 9 here https://www.omc-stepperonline.com/download/DM542T.pdf


Actually I do have it,  it is very similar to the one you mentioned above.


It tells you things like how long you need to hold the "DIR" pin before the
next step pulse and  the minimum pulse widths.
The one I have also needs to have the DIR set 5us before you do anything 
else

I'd make them all larger than needed by about 4X because you are not trying
to make these go fast.  In fact, a 50% duty cycle square wave works fine.


So you'd set the wait after the DIR 20us?   and PUL the duty cycle  
10us,  5us hi then 5us lo?


I set it up so that it is 'variable' in a mem-shared array, so I can 
change some parameters (for example because of feedback from the 
encoders, or by 'manually' adjusting it.) while the threads keep running.



What you do is in the loop when you set a pin high you store the time for
when it must be set low and every time through the loop you do whatever has
a time-to-do that is expired.  You can juggle N balls at once in one loop
this way.


What I am doing is use multiple threads,  I am writing it in C, and use 
a separate pthread for each stepper-driver / motor.


Once the telescope starts tracking, only one motor/thread will run, the 
other two are mostly 'idling. '.



thanks! that was what I was somewhat looking for, some actuall number I 
can use that work and go from there.  The speed just depends on how much 
time there is between the duty cycles,  at least tat is what I noticed, 
correct?



Would it be better to use a higher number of steps?  The manual seems to 
indicate that I can almost use any setting there with a "1.8 degrees 
steppermotor", which somewhat surprised me.


Ron



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Re: [Emc-users] off topic: pwm with a stepper driver/motor

yup exactly,  actually in a way  so I can point at things that you can't 
really see but  would need longer exposures for.


On 7/13/20 9:28 PM, Chris Albertson wrote:

On Mon, Jul 13, 2020 at 8:02 PM Dave Matthews  wrote:


It may just be my age but wouldn't it be easier to just use a 555 (do they
still make them) and a knob to tweak the pulse rate to match the star?


That would be easy but I think there is some plan to have a "go to"
ability where the 'scope slews to a target selected from a database.

Also, a full-up computer today sells for the same price as a 555 chip.  You
can get an AVR (Arduino chip) in an 8-pin package for just a few cents.



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Re: [Emc-users] off topic: pwm with a stepper driver/motor

yeah that would be easiest, but I want to do something similar for
azimuth and altitude.

On 7/13/20 9:00 PM, Dave Matthews wrote:

It may just be my age but wouldn't it be easier to just use a 555 (do they
still make them) and a knob to tweak the pulse rate to match the star? Add
a slew button to change the speed while the button is pushed and a
direction switch to toggle the direction pin on the driver. I guess I
don't see the need for a computer to run a stepper at a constant speed.

Dave

On Mon, Jul 13, 2020, 22:46 R C wrote:

well, I can calculate what the speed needs to be, also I can actually
"observe" it too.. by pointing the telescope at a star and see how
much the deviation is. I have encoder to check the actual speed of a
shaft.

I found some information in a manual/tech-sheet that comes with the
drivers, so I am trying to figure out what the best stepping rate is and
what the best way of actually sending pulses to the stepper-driver is.

I wrote some c-code that runs the motors in pthreads, I just want to
know what the best way is. pulse lengths, pause/gap length etc.
(basically the best way to use a dm542 (all those steppers are sorta
the same I understand)

The driver tech-sheet basically says it can do pretty all it's
available micro stepping with a 1.8 degree stepper motor, I wonder if
that is really true.

Ron

On 7/13/20 8:35 PM, Chris Albertson wrote:

A fast control loop that drives each motor at a given speed and a second
slower control loop that figures out what that speed should be. The
second loop typically uses "PID" even if only in fact the "P" is used.

That can be used to drive any number of motors all at their correct

speeds.

On Mon, Jul 13, 2020 at 7:28 PM R C wrote:

Interesting,

but I already have the motors, and the gears are on their way. What
I was really looking for is how to drive the stepper-drivers, he DM542
series ones.

Ron

On 7/13/20 7:53 PM, cogoman via Emc-users wrote:

I recently discovered geared stepper motors.

http://www.zyltech.com/nema-17-stepper-motor-geared-planetary-gearbox-1-7-a-3-1-nm-435-ozin/

I've been happy with zyltech in the past. I bought one of these for
evluation, but the specs seem to be great for CNC. Low enough current
to work with a stepstick, High enough torque for a fairly powerful
machine, and less than 4 mH inductance should let it step pretty fast.

5.18:1 gear ratio should reduce that 4 meter spur gear, but the link
below has higher gear ratios that would reduce that spur gear greatly!
Backlash could be a problem for CNC, but if you are only going one
way, the less precision gearboxes might be fine.

https://www.omc-stepperonline.com/geared-stepper-motor/?sort=p.price&order=ASC

Once you visit the stepperonline web page you know as much about them
as I do, but their offerings might be just right for your application.

On 7/9/20 2:23 PM, R C wrote:

Hello,

this is (probably) off topic, been seen that happen. If it is please
ignore it.

I am building a "motorized" telescope mount (dobsonian) with what is
called an equatorial platform, it has 3 axis which I am going to
drive with stepper motors.

The stepper motors I use with a stepper driver, those common DM542
ones, the stepper motors themselves are 2A and 1.8 degrees per step.

What I want to accomplish with the equatorial platform) (it
compensates for the rotation of the earth) is that, the start and
end position accuracy is not that important, smooth and
constant/consistent movement is. for the azimuth/altitude precision
is not a really big deal, but you'd want to move these 2 axis
somewhat swift.

So there are a few factors to decide.

I probably want micro stepping, what settings on the driver for
pulses per rev, is best to use (or is that just trial and error?)

As with PWM itself, I am probably just not too familiar with it. From
what I understand, the voltage I use for the motors determines how
fast I can go (I am going to use a 48V switching power supply).

as for PWM, I can of course change the length of the pulse itself
and, independently, change the time between two pulses. What is the
relation ship there? WHat does a longer width of the pulse itself
do? and what exactly does a longer gap between the pulses do (of
course the wider the gap between two pulses the slower the motor

turns).

for, especially, the equatorial platform, I want to avoid "jerking"
it, meaning starting and stopping the stepper motor as little as
possible and just go at a 'slow' constant speed.

sorry if totally of topic

thanks,

Ron

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Re: [Emc-users] off topic: pwm with a stepper driver/motor

The driver tech-sheet basically says it can do pretty all it's
available micro stepping with a 1.8 degree stepper motor, I wonder if
that is really true.

Ron

On 7/13/20 8:35 PM, Chris Albertson wrote:

That can be used to drive any number of motors all at their correct speeds.

On Mon, Jul 13, 2020 at 7:28 PM R C wrote:

Interesting,

but I already have the motors, and the gears are on their way. What
I was really looking for is how to drive the stepper-drivers, he DM542
series ones.

Ron

On 7/13/20 7:53 PM, cogoman via Emc-users wrote:

I recently discovered geared stepper motors.

http://www.zyltech.com/nema-17-stepper-motor-geared-planetary-gearbox-1-7-a-3-1-nm-435-ozin/

https://www.omc-stepperonline.com/geared-stepper-motor/?sort=p.price&order=ASC

Once you visit the stepperonline web page you know as much about them
as I do, but their offerings might be just right for your application.

On 7/9/20 2:23 PM, R C wrote:

Hello,

this is (probably) off topic, been seen that happen. If it is please
ignore it.

I am building a "motorized" telescope mount (dobsonian) with what is
called an equatorial platform, it has 3 axis which I am going to
drive with stepper motors.

The stepper motors I use with a stepper driver, those common DM542
ones, the stepper motors themselves are 2A and 1.8 degrees per step.

So there are a few factors to decide.

I probably want micro stepping, what settings on the driver for
pulses per rev, is best to use (or is that just trial and error?)

for, especially, the equatorial platform, I want to avoid "jerking"
it, meaning starting and stopping the stepper motor as little as
possible and just go at a 'slow' constant speed.

sorry if totally of topic

thanks,

Ron

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Re: [Emc-users] off topic: pwm with a stepper driver/motor

Interesting,

but I already have the motors, and the gears are on their way. What
I was really looking for is how to drive the stepper-drivers, he DM542
series ones.

Ron

On 7/13/20 7:53 PM, cogoman via Emc-users wrote:

I recently discovered geared stepper motors.

http://www.zyltech.com/nema-17-stepper-motor-geared-planetary-gearbox-1-7-a-3-1-nm-435-ozin/

https://www.omc-stepperonline.com/geared-stepper-motor/?sort=p.price&order=ASC

Once you visit the stepperonline web page you know as much about them
as I do, but their offerings might be just right for your application.

On 7/9/20 2:23 PM, R C wrote:

Hello,

this is (probably) off topic, been seen that happen. If it is please
ignore it.

I am building a "motorized" telescope mount (dobsonian) with what is
called an equatorial platform, it has 3 axis which I am going to
drive with stepper motors.

The stepper motors I use with a stepper driver, those common DM542
ones, the stepper motors themselves are 2A and 1.8 degrees per step.

So there are a few factors to decide.

I probably want micro stepping, what settings on the driver for
pulses per rev, is best to use (or is that just trial and error?)

for, especially, the equatorial platform, I want to avoid "jerking"
it, meaning starting and stopping the stepper motor as little as
possible and just go at a 'slow' constant speed.

sorry if totally of topic

thanks,

Ron

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Re: [Emc-users] off topic: pwm with a stepper driver/motor



On 7/10/20 8:26 PM, Ken Strauss wrote:

"You need more gearing with the DC motor." Correct and this could be
considered an advantage since a very small DC motor + gearing (multiple
planetary stages) would have sufficient torque to move the scope. I have no
idea if a RPI can keep up with 3 quadrature encoders and control 3 motors
and manage a UI. However, you could make a compact unit at low cost
containing a microprocessor that takes step/dir, tracks encoder position and
generates PWM to run the motor. Rather like a low power, low RPM, high
torque version of a Clearpath servo.



Well   the shafts are not rotating "that" fast  if an RPI can easily do  
2000rpm, with a 100ppr encoder it can do 3 400 ppr encoders at 1 or 2 or 
3 rpm easily


These RPIs are pretty fast little things; with a 400 PPR encoder,  with 
3 there would be 1000-2000 pulses in a minute... that is easy to do





-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com]
Sent: Friday, July 10, 2020 10:14 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] off topic: pwm with a stepper driver/motor

Stepper motors are good for this.   A stepper has the most torque at zero
RPM and the torque falls as speed increases while a DC brushed motor has
very little power when moving slowly.  You need more gearing with the DC
motor.

The problem is you need to generate precise pulses.  If the pulse spacing
is not accurate then you are asking a large telescope to accelerate and
decelerate instantly. So to generat pulses need either
1) a hardware solution like a microcontroller or FPGA or pulse generator.
2) A real time kernel on the Linux system or
3) A PID loop to supervise a non-real-time software pulse generator

When I build stuff, my preference is the microcontroller.  I design it so
the microcontroller can work independent of a larger Linux computer or

take

commands from a large Linux computer.  I want some basic functionality
when
power is applied then adding the Linux PC adds more functionality.

Linux CNC uses a slightly different idea they either go with Real-Time
Linux or use a very simple pulse generator running in an FPGA.

Reading up to three quadrature encoders with just a Raspberry Pi might
work, or not.  I don't know.  A lot depends on the speed of the encoders.

On Fri, Jul 10, 2020 at 6:45 PM R C  wrote:


I don't think anyone did,  but I know that's how most do it...

But that's just too easy  :)I would just like to see if I can do it,
killing time


On 7/10/20 7:39 PM, Ken Strauss wrote:

I haven't been following this closely but has anyone suggested that

you

use a

DC motor with an encoder? With a PID loop and PWM power to the motor

you

could

run the motor continuously. DC motors with integrated encoder and

planetary

gearbox are readily available for a few dollars. Just a thought.




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--

Chris Albertson
Redondo Beach, California

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Re: [Emc-users] off topic: pwm with a stepper driver/motor

right that is how most people use it...   BUT it would still be hard to 
calibrate the movement to the earths rotation.



and also  ..   I just want to do it with steppers   :)    I am weird

On 7/10/20 8:14 PM, Ken Strauss wrote:

You could use the DC motor + PID exactly the same as using steppers. With the
encoders you would always know the exact angle though which the motor had
rotated. The advantage would be the lack of any jerks in motion which are
inherent with a stepper. Have you considered using the Clearpath units? See
https://www.teknic.com/



-Original Message-
From: R C [mailto:cjv...@gmail.com]
Sent: Friday, July 10, 2020 10:05 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] off topic: pwm with a stepper driver/motor

yep..  true..  but it is also knd of what I do for a living...


I think it can be done,  to build an equatorial platform, and really
control it's speed/angle over time.


On 7/10/20 7:52 PM, Ken Strauss wrote:

I also waste a lot of time exploring different ways of doing things but
frequently end up doing it the traditional way. One should never just
accept
"how it is done" but for many (most?) things there are good reasons for
traditional ways.


-Original Message-
From: R C [mailto:cjv...@gmail.com]
Sent: Friday, July 10, 2020 9:43 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] off topic: pwm with a stepper driver/motor

I don't think anyone did,  but I know that's how most do it...

But that's just too easy  :)I would just like to see if I can do it,
killing time


On 7/10/20 7:39 PM, Ken Strauss wrote:

I haven't been following this closely but has anyone suggested that you
use a
DC motor with an encoder? With a PID loop and PWM power to the

motor

you could

run the motor continuously. DC motors with integrated encoder and

planetary

gearbox are readily available for a few dollars. Just a thought.




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Re: [Emc-users] off topic: pwm with a stepper driver/motor



On 7/10/20 8:13 PM, Chris Albertson wrote:

Stepper motors are good for this.   A stepper has the most torque at zero
RPM and the torque falls as speed increases while a DC brushed motor has
very little power when moving slowly.  You need more gearing with the DC
motor.


that is exactly right, that is why I wanted to try going that route


The problem is you need to generate precise pulses.  If the pulse spacing
is not accurate then you are asking a large telescope to accelerate and
decelerate instantly. So to generat pulses need either
1) a hardware solution like a microcontroller or FPGA or pulse generator.
2) A real time kernel on the Linux system or
3) A PID loop to supervise a non-real-time software pulse generator


yes I agree on the first part..   :)   BUT   this is not a high speed 
thing and changes at high speed are more "disruptive"  then changes at 
something that goes rather slow


the 3 solutions you mention work if you really want to be on top.  The 
thing is..   it is not really that bad if you're a fraction of a second 
off, with an amature telescope.


(but perfect is cool  :)   )



When I build stuff, my preference is the microcontroller.  I design it so
the microcontroller can work independent of a larger Linux computer or take
commands from a large Linux computer.  I want some basic functionality when
power is applied then adding the Linux PC adds more functionality.


Yes definitely... a micro controller would be something "small" that 
works predictable   BUT it is hard to interact with and make adjustments.


I worked with micro controllers,  they are great for repetitive stuff 
that don't need interaction/correction




Linux CNC uses a slightly different idea they either go with Real-Time
Linux or use a very simple pulse generator running in an FPGA.


right.  I use linux cnc and really like it for my mill and lathe. 
Actually, if you abstract it..  a telescope is sort of a machine that 
points at "something" similar like a mill does.


the degrees of freedom are different, but not that different. I think a 
telescope can be sort of "defined"  with 4 degrees of freedom,  however, 
2 of them (orbit and rotation of the earth) are constrained.  If you 
look at it,  it would be like a 4 or 5 axis mill  running a program 
doing nothing except pointing at some star, which is the same 
functionality as it milling some "object"


That is not why I posed the question here though.   I did because I  
knew that Linux CNC knows how to work with drivers and steppers,  and I 
am trying to do something similar with the hardware that I use in my 
little mill and lathe and mill, running linux cnc





Reading up to three quadrature encoders with just a Raspberry Pi might
work, or not.  I don't know.  A lot depends on the speed of the encoders.


well   the speed of rotation is not that high, so one is not as much 
measuring speed,  but more position...   so  that would be a few hundred 
pulses per revolution


I tried a few scenarios...  it doesn't seem to be a real problem to get 
a few hundred pulses in a few seconds at all.





On Fri, Jul 10, 2020 at 6:45 PM R C  wrote:


I don't think anyone did,  but I know that's how most do it...

But that's just too easy  :)I would just like to see if I can do it,
killing time


On 7/10/20 7:39 PM, Ken Strauss wrote:

I haven't been following this closely but has anyone suggested that you

use a

DC motor with an encoder? With a PID loop and PWM power to the motor you

could

run the motor continuously. DC motors with integrated encoder and

planetary

gearbox are readily available for a few dollars. Just a thought.




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Re: [Emc-users] off topic: pwm with a stepper driver/motor


yep..  true..  but it is also knd of what I do for a living...


I think it can be done,  to build an equatorial platform, and really 
control it's speed/angle over time.



On 7/10/20 7:52 PM, Ken Strauss wrote:

I also waste a lot of time exploring different ways of doing things but
frequently end up doing it the traditional way. One should never just accept
"how it is done" but for many (most?) things there are good reasons for
traditional ways.


-Original Message-
From: R C [mailto:cjv...@gmail.com]
Sent: Friday, July 10, 2020 9:43 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] off topic: pwm with a stepper driver/motor

I don't think anyone did,  but I know that's how most do it...

But that's just too easy  :)I would just like to see if I can do it,
killing time


On 7/10/20 7:39 PM, Ken Strauss wrote:

I haven't been following this closely but has anyone suggested that you
use a
DC motor with an encoder? With a PID loop and PWM power to the motor

you could

run the motor continuously. DC motors with integrated encoder and

planetary

gearbox are readily available for a few dollars. Just a thought.




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Re: [Emc-users] off topic: pwm with a stepper driver/motor


I don't think anyone did,  but I know that's how most do it...

But that's just too easy  :)    I would just like to see if I can do it, 
killing time



On 7/10/20 7:39 PM, Ken Strauss wrote:

I haven't been following this closely but has anyone suggested that you use a
DC motor with an encoder? With a PID loop and PWM power to the motor you could
run the motor continuously. DC motors with integrated encoder and planetary
gearbox are readily available for a few dollars. Just a thought.




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Re: [Emc-users] off topic: pwm with a stepper driver/motor

from what I understand,  worm gears work really well  and because of the 
reduction, the motor needs to sping at a decent rpm, it doesn't have 
tospin that slow. I am using steppers, because it is easy to count the 
steps and then calibrate because of how much you're drifting.While with 
a regular DC motor you could only do something like that in a 
Monte-Carlo/binary kinda way. also, adjusting DC motors is not 
necessarilly  linear and since adjusting a stepper is "discrete" it 
would be way easier.


On 7/10/20 1:21 PM, andy pugh wrote:

On Fri, 10 Jul 2020 at 20:14, Chris Albertson  wrote:


You need to move at 1/2 the resolution otherwise you can see the steps.  So
let's say each step would be 1/4 arc-second

I was going with one step per thingy, and then assuming microstepping
to get sub-thingy :-)

I will just mention: https://www.hpcgears.com/pdf_c33/22.0.pdf as an option.
(With a home-made worm. I am assuming that anyone here can cut a module thread)




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Re: [Emc-users] off topic: pwm with a stepper driver/motor


On 7/10/20 1:12 PM, Chris Albertson wrote:

On Fri, Jul 10, 2020 at 10:33 AM andy pugh  wrote:


Sprockets for T2.5 belts are available with 10 teeth, so that would be
a 2.3m table for the 300:1. Which is also probably too big. I suppose
that the design criterion is that one stepper step should be less than
the angular resolution of the telescope. So what is that, in this
case?

We don't know the size of this 'scope but let's assume about 12" 
diameter.

then it is on the order of 1/2 arc-second


If you're talking about my telescope, it's an 8"



You need to move at 1/2 the resolution otherwise you can see the 
steps.  So

let's say each step would be 1/4 arc-second

Stars move 15 degrees per hour or 15 arc-seconds per second.   So he 
needs

to step at about 60 Hz.


That sounds about right, but I am planning on using a worm gear too..  
so the motor can continuously spin.


(I also heard from people that built those platforms and experimented 
with them, that some "shaft couplers"


reduce vibration quite a bit




Let's assume 1/64th micro steps  these are roughly 100 arc-seconds per
step.  He needs about 400:1 gear reduction.

This is getting unreasonable because the telescope will NEVER achieve the
theoretical resolution because of the atmospheric blurring  Lets say 
we do

1 arc-second steps and 100:1 gears.


Yup, and then there's wind etc too, and telescopes are also good 
detectors for picking up vibrations from the ground.




The traditional professional-level method is to use very nice and very
expensive brass wheels and stainless steel worms and even more expensive
bearings and shafts.   But nowadays with computers, we can place a camera
such that it looks at the image of a highly magnified star then we 
measure
the X,Y location of the image on the CCD sensor and use a PID feedback 
loop
to keep the star image from moving.  So the servo loop tries to keep 
drift

to zero.  They measure drift with units called "mas" for milliarcseconds.

I am actually trying to see if I can build something like that too


But this is a "Dobsonian" scope and the goal of these is to be cheap and
portable, exactly the opposite of a professional level scope. Most of
these use a door hinge as the axis that is roughly aligned by eyeball 
with

"north" and the drive is a hardware store threaded rod turned by a DC
geared DC motor and the operator sets the tracking speed by eye and hand.
These things reduce the drift to what can be tracked with the eye.
I read about barndoor equatorial platforms, those are mostly used for 
cameras. Also wouldn't really work with a dobsonian mount, since the 
telescope would start tipping. The actul equatorial platform runs in a 
"cone", with elliptical  tracks on a bearing. You'd turn one of the axis 
in a bearing and move the whole platform around the center of gravity 
(or close) of the telescope. At least that is what most of the plans say 
to do.


It seems our OP is trying to do better than the common door hinge and
threaded rod tracker but still wants a 'scope that fits in the back of 
his
car and costs less than the car.   So sub-arcsecond pointing is going 
to be

hard.


Yes definitely. A dobsonian telescope has a newtonian tube, also called 
light buckets, they can collect a lot of light, however because of their 
size, having a good stable equatorial mount is difficult, that's why 
they came up with the dobsonian mount. That mount works very well for 
"direct" star gazing,  you just move it when you need to. Looking at 
Saturn is a bit of a challenge that way already though. The equatorial 
platform seems to work really well and one can track something for 
approx. an hour or hour and a half.



The barndoor platform  seems to work well when you  look at stars near 
polaris, or opposite of it, but other directions make it just 
unpractical because of "balancing issues"



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Re: [Emc-users] off topic: pwm with a stepper driver/motor



On 7/9/20 6:47 PM, Chris Albertson wrote:

OK, got it a "Dob, on a Ea, platform and the platform on an Az, El mount.



Yup.



Again PWM is "Pisle Width Modulation"  Steppers and stepper drivers don't
use PWM.  They use what we cal "Pulse/Direction"
I didn't know that,  I read the product manual, it mentioned PWM, with 
some specs, I tried that, seems to kinda work   well work as in a  
okcupid profile that says "I don't like drama and games" but some how it 
doesn't seem to do what expected.


PWM uses a constant square wave rate like that is always between 60 Hz and
maybe up to 1,000 Hz.  What changes is the "duty cycle" or the ratio of
"on" to "off".  But it just runs at about 60Hz.  PWM uses just one wire.


Right,  and some hardware let's you pick the frequency, up front..  and 
then change the duty cycles.  that is what I figured. However, I saw in 
the manual,  the "high" side of the pulse in the duty cycle" lasts 
always 2.5usec and you change the length of the cycle. To me that just 
seems that you change the duty cycle, relative to the frequency...   as 
in the frequency is determined by how you build the cycles..   which is 
what I see happening.





Pulse/Direction uses two wires.  One sends a single pulse each time the
motor needs to move a step and the other wire is either "1" or "0" to
indicate the direction, either backward or forward.


correct,  direction is either constantly high, or constantly low..  for 
how long you want it...   and that works perfectly





With this type of system I don't think you worry about minor things like
atmospheric refraction of structural flex.  You can just run at a constant
rate.


Yes ..  at this point I am not worried about that. I want to make a 
"mechanical" precise contraption.





I am wondering why you selected a Raspberry Pi and not some micro
controller.  Perhaps you are planning a user interface that is complex?


well..  sort of.  I am planning on one that does the "positioning,  one 
that does the imagng  and if needed one that does that "positioning"


I use them because they are easy to use,  run Linux, I know Linux, 
hardware..  I can hook it up to a network,  and see if I canhave 
Stellarium" send coordinates to it at some point. It is more a "olution" 
that I can build on and expand   if I wanted to.   There are very 
compact  solutions to use,  that are cheaper, easier etc..   BUT  I want 
o build my own my way,.


I built a seismograph like that, could be done easier/cheaper, but I 
wanted to build an online one and do it myself ...   just because I can 
..   and because I think it can be done.


I'm a researcher/scientist,  I like to build things so I can figure out 
how it works...




All you software needs to do is generate  plusle each time the motr needs
to step.   For the motor that runs the EQ platform this step rate is fixed
forever.  For the other two they can step at whatever rate do want.


Yes exactly,  that is what I noticed.  I can move the stepper at pretty 
much any desired rate/speed I want,  pretty precise, and.. if it runs at 
the exact right speed.  that would be cool.


BUT,  I want to know how to figure out how to run it at the exact right 
speed, with the exact right power, optimally, as best as I can ..   and 
not by trial and error and decide "yeah good enough",  I want to 
calculate it.


So that is why I want to understand what the best way is , software 
wise, to drive those steppers,  to run those motors, algorithm wise.





Why encoders?  If the motors are proerly sized they will never skip steps
and you can count steps to know where you are.  If you put on encoders you
just need to  encoder steps


The encoders are just there to check,  and fun to play with..  or more 
seriously...


I use the encoders similar to a prenup,  hope I don't need it/them to 
correct  mis-steps...  but it doesn't hurt to have






On Thu, Jul 9, 2020 at 1:48 PM R C  wrote:


there will be worm gears, and those will just gear all the axis/axes
down down.

On 7/9/20 1:23 PM, Chris Albertson wrote:

Telescopes are something I know a little about, What you don't tell us

and

what matters quite a lot is the mechanical gearing.  How are the
motors connected to the mount?

there will be worm gears, and those will just gear all the axis/axes
down down. the 3 motors are going to be connected to a stepperdriver
(DM542 or so) and the stepper drivers are 'driven' by an raspberry pi
(mounted in the mount) and I am using a quadrature encoder on  all 3, on
the shaft that drives the main gear on each motor.


If this is an equatorial mount what are there three motors?  and why care
much about if declination moves smoothing as it is only for slewing to a
new target.


It is not exactly an equatorial mount, it is an equat

Re: [Emc-users] off topic: pwm with a stepper driver/motor

I am not using linux cnc,  I am just  'driving'  the stepper drivers 
with a raspberry pi



I figured,  same hardware (drivers, motors),  "Linux CNC" can use it, so 
thought I'd just ask here about the internals/specifics and how to use it.



On 7/9/20 1:44 PM, andy pugh wrote:

On Thu, 9 Jul 2020 at 19:26, R C  wrote:


The stepper motors I use with a stepper driver, those common DM542 ones,
the stepper motors themselves are 2A and 1.8 degrees per step.

...

As with PWM itself, I am probably just not too familiar with it.

Do you mean PWM?

Stepper drivers take step and direction, not PWM.

I think this is a job for an Arduino, rather than LinuxCNC.
Especially as I assume that an equatorial mount runs at an absolutely
constant rate anywhere in the world?




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Re: [Emc-users] off topic: pwm with a stepper driver/motor


Hello Gene,


To start with the end of your reply,  I actually am a mathematician  :)


On 7/9/20 4:24 PM, Gene Heskett wrote:

On Thursday 09 July 2020 14:23:57 R C wrote:


Hello,

this is (probably) off topic, been seen that happen.  If it is please
ignore it.


I am building a "motorized"  telescope mount (dobsonian) with what is
called an equatorial platform, it has 3 axis which I am going to drive
with stepper motors.


The stepper motors I use with a stepper driver, those common DM542
ones, the stepper motors themselves are 2A and 1.8 degrees per step.


What I want to accomplish with the equatorial platform)  (it
compensates for the rotation of the earth) is that,  the start and end
position accuracy is not that important,  smooth and
constant/consistent movement is.  for the azimuth/altitude precision
is not a really big deal, but you'd want to move these 2 axis
somewhat swift.


So there are a few factors to decide.


I probably want micro stepping,  what settings on the driver for
pulses per rev, is best to use (or is that just trial and error?)


I think the gear ratio is as important as the microstepping ratio which I
would probably set to 8 or 16 with the dip switches on the dm542's. Any
higher than that and the higher speeds need stepper pulses faster than
the opto's in the DM542 inputs which will limit your top speed to just
north of 200 kilohertz for a step rate.


Correct, the  gear ratio and stepper resolution are important, so is 
leverage/torque..  and well..  space to put it.   To move the mount


on it's vertical axis, azimuth,  and to move the  newtonian tube, the 
latitude, U use 360 teeth gears, because they are bigger and have more 
"leverage", so


I can move  them easier/faster (somewhat, that is a trade off too).




Next is the resolution of your mirror, so you would want it to move about
4 microsteps to see it visibly move in the eyepiece.


The one I am doing this with is not that big,  it is an 8" main mirror.


Then if you are well balanced and running on ball bearings for low
friction on all 3 axis's, you may want to experiment with the motor
current to see if a certain current gets you a more even movement, some
drivers, and I haven't asked, nor tried to prove that 1/8th or 1/16 step
gives the same movement as it depends both on the currant mapping used
by the DM542 driver and the magnetic (iron) properties of the motor.


Yes they all have ball bearings,  a big "lazy susan" style one betwen 
platform and mount,  pillow/pocket bearings for the


elliptical friction "runners".  However, kepping the Azimuth 
bearing/joint and latitude bearing/joint steady for a dobsonian is more 
important..  they kinda need to be "locked"  when on a target.


The equatorial platform needs to run smoothly and steady, no or little 
"jerking"



That is something I want to experiment/try/figure-out   if there is a 
micro stepping setting that  would be best to use. The 
smoother/constant/consistent I mover the EQ


platform the better. That is where micro stepping and speed comes in I 
think. If I can continuously can keep moving without stopping, slowing 
down, speed up, the better it is probably.





As with PWM itself, I am probably just not too familiar with it. From
what I understand, the voltage I use for the motors determines how
fast I can go (I am going to use a 48V switching power supply).

Steppers aren't pwm driven, so ignore that. But a 48 volt supply is
pushing the ratings of a DM542 which is 50 volts max, and you would be
wise to adjust it a few volts lower. I have a pair of 7.5 amp 48 volt
supplies running my 11x56 Sheldon lathe, but they are turned down to
42.5 volts, much safer, and it still marches at way faster speeds than
needed for a good cut.


I can do that, I can put a voltage regulator between them.   What do you 
mean by "safer" btw?



as for PWM,  I can of course  change the length of the pulse itself
and, independently, change the time between two pulses. What is the
relation ship there?  WHat does a longer  width of the pulse itself
do?  and what exactly does a longer gap between the pulses do (of
course the wider the gap between two pulses the slower the motor
turns).


for, especially, the equatorial platform, I want to avoid "jerking"
it,  meaning  starting and stopping the stepper motor as little as
possible and just go at a 'slow' constant speed.


LinuxCNC has "adjustment knobs" for that, but are set with a text editor
and forgotten once done.  Slewing to another star can be done with a
second or more to get to speed, and a slowdown in approaching the new
target so "jerk" can be very low.


I am not too worried about that part,  zooming in on an object, that is 
fine,  I could do that  manually, well remotely.  and once "locked in"  
keep it steady and start the EQ platform.


I am also terribl

Re: [Emc-users] off topic: pwm with a stepper driver/motor



On 7/9/20 1:44 PM, andy pugh wrote:

On Thu, 9 Jul 2020 at 19:26, R C  wrote:


The stepper motors I use with a stepper driver, those common DM542 ones,
the stepper motors themselves are 2A and 1.8 degrees per step.

...

As with PWM itself, I am probably just not too familiar with it.

Do you mean PWM?


yes




Stepper drivers take step and direction, not PWM.


correct,  but the direction is either high or low,  while the PUL (step) 
ping/port takes PWM signals, which you can easily create with a RPI,  I 
have that part working.  I have the impression that on the 
stepperdriver, the pulswidth is constant a table in the docs shows that 
, so the duty cycle is always  2.5us of power and then some delay   so 
if a cycle iis 2.5us hi,  2.5us low and then 5us low, the duty cycle is 
10us at 50%..    and if   hi is 2.5 us, the low is 2.5us, the duty cycle 
is5us, at 100%   etc.


That is what I wanted to ask,  if that is correct   because 
typically you would set the input frequency,  and that gives you a duty 
cycle length,  and  the width of the pulse (plus the voltage) would 
dictate the power.  but  with these drivers,  the  pule width seems 
fixed ??   and the frequency can pretty much can be anything less then 200k




I think this is a job for an Arduino, rather than LinuxCNC.
Especially as I assume that an equatorial mount runs at an absolutely
constant rate anywhere in the world?

well, I am not using CNC  (that is why I called it off topic) unless 
anyone would ever like to build that into it... (instead of a mill and 
lathe, add a telescope.. *lol* )...   an Arduino wouldn't do anything 
different than the RPI does. I can make the motor run at different 
speeds etc..   just want to know the relation between dutu cycle and 
pulse length ..



Ron

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Re: [Emc-users] off topic: pwm with a stepper driver/motor

.  
then move the scope to the object and keep it there. so AZ and Alt are 
holding.  the EQ starts moving, in order to track.




One thing you really want is FEEDBACK from a guide star or even from the
main camera.  A guid camera can detect feild drife and change the speed of


sure,  maybe some day..   for now I am using rotary encoder ..  I have a 
few 400ppr quadrature encoders lying around, they are very small.)




the motor compensate. Drift is caused by (1) changes in
atmospheric refraction as the target moves and (2) the telescope mount
flexing as the scope moves.   Some sophisticated software tries to model
this and calculate the effect but a close loop is best and now days cheap
to do.

Last time I did this we used NTP to keep the controller's clock
synchronized to actual time.  We used a local GPS receiver to create a
local NTP server

Yes, one could use LinuxCNC to drive the motors it might be easier to just
use a microcontroller.



That is what I thouht of when I saw an older post about  using CNC  for 
an rc model (a plane or so?)






So I have  the mechanical parts figured out, and how to do some 
reasonable tracking.   What I am after is how to best  make the stepper 
drivers work.



With PWM signals I can 'drive' the stepperdrivers and I can move the 
stepper motors,  I am just trying to figure out what the best method9s) 
are. for example what the connection is between pulses that are 
longer..  or shorter pulses with larger gaps between them.



Ron



On Thu, Jul 9, 2020 at 11:26 AM R C  wrote:


Hello,

this is (probably) off topic, been seen that happen.  If it is please
ignore it.


I am building a "motorized"  telescope mount (dobsonian) with what is
called an equatorial platform, it has 3 axis which I am going to drive
with stepper motors.


The stepper motors I use with a stepper driver, those common DM542 ones,
the stepper motors themselves are 2A and 1.8 degrees per step.


What I want to accomplish with the equatorial platform)  (it compensates
for the rotation of the earth) is that,  the start and end position
accuracy is not that important,  smooth and constant/consistent movement
is.  for the azimuth/altitude precision is not a really big deal, but
you'd want to move these 2 axis  somewhat swift.


So there are a few factors to decide.


I probably want micro stepping,  what settings on the driver for pulses
per rev, is best to use (or is that just trial and error?)


As with PWM itself, I am probably just not too familiar with it. From
what I understand, the voltage I use for the motors determines how fast
I can go (I am going to use a 48V switching power supply).


as for PWM,  I can of course  change the length of the pulse itself
and, independently, change the time between two pulses. What is the
relation ship there?  WHat does a longer  width of the pulse itself do?
and what exactly does a longer gap between the pulses do (of course the
wider the gap between two pulses the slower the motor turns).


for, especially, the equatorial platform, I want to avoid "jerking" it,
meaning  starting and stopping the stepper motor as little as possible
and just go at a 'slow' constant speed.



sorry if totally of topic


thanks,


Ron



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[Emc-users] off topic: pwm with a stepper driver/motor


Hello,

this is (probably) off topic, been seen that happen.  If it is please 
ignore it.



I am building a "motorized"  telescope mount (dobsonian) with what is 
called an equatorial platform, it has 3 axis which I am going to drive 
with stepper motors.



The stepper motors I use with a stepper driver, those common DM542 ones, 
the stepper motors themselves are 2A and 1.8 degrees per step.



What I want to accomplish with the equatorial platform)  (it compensates 
for the rotation of the earth) is that,  the start and end position 
accuracy is not that important,  smooth and constant/consistent movement 
is.  for the azimuth/altitude precision is not a really big deal, but 
you'd want to move these 2 axis  somewhat swift.



So there are a few factors to decide.


I probably want micro stepping,  what settings on the driver for pulses 
per rev, is best to use (or is that just trial and error?)



As with PWM itself, I am probably just not too familiar with it. From 
what I understand, the voltage I use for the motors determines how fast 
I can go (I am going to use a 48V switching power supply).



as for PWM,  I can of course  change the length of the pulse itself  
and, independently, change the time between two pulses. What is the 
relation ship there?  WHat does a longer  width of the pulse itself do?  
and what exactly does a longer gap between the pulses do (of course the 
wider the gap between two pulses the slower the motor turns).



for, especially, the equatorial platform, I want to avoid "jerking" it,  
meaning  starting and stopping the stepper motor as little as possible 
and just go at a 'slow' constant speed.




sorry if totally of topic


thanks,


Ron



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Re: [Emc-users] Maths (wow)

2020-06-26 Thread R C

that is funny,  I am a mathematician, and actually took several classes 
involving


projective geometry. What is shown is somewhat of "special case" 
scenarios it seems.



I don't really see how projective geometry would apply to anything cnc, 
or be helpful, or apply


to anything "real world" for that matter. It's part of a field called 
'topology', which, at the


time, was kinda a prestigious thing to do. (now I think of it as a 
conspiracy theory to sell lots of advil).



Ron


On 6/26/20 7:24 PM, andy pugh wrote:

I was watching this presentation, and it was all rather interesting,
but not directly relatable to LinuxCNC.
https://youtu.be/tX4H_ctggYo

But then this happened:
https://youtu.be/tX4H_ctggYo?t=4443




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Re: [Emc-users] Universal spindle speed control for $7

2020-06-19 Thread R C

Sure,  but it works..   and   *lol*    Linux is not good at "Real Time" 
? , nothing is good at real time (depending on what you call real time), as

long as you can complete some operations with a given amount of time.  
(I work on time sensitive stuff, "real time" issues at scale for a 
living, not

too many issues with a little encoder in particular.

On 6/19/20 1:59 PM, Chris Albertson wrote:
The Pi is a really horrible platform for reading high speed 
quadrature. Sorry to say but you'd be far better off using a $3 to $10 
ARM-based development board.   I have a few Pi3 and Pi4 here. I 
typically use the $3 boards for real-time stuff like encoders and 
motor control and place the calculations and user interface on the Pi3 
or Pi4.

The little cheap boards don't miss counts and don't run Linux Kernels. 
For motion control, I like to place that on the ARM micro and then 
connect that to the Pi via USB.  The Pi sends "move-to" and speed 
commands and the Micro sends position and velocity updates at perhaps 
20Hz back to the Pi.  No, I did not invent this. The idea is common.   
Linux is just not good at "real-time" even with an RT kernel.  The 
ARM-M on the other hand is perfect for real-time.

Notice the setup that "everyone" uses to control machine tools.  
Linux/RT connected to Mesa/FPGA.  This is logically the same as Pi4 
connected to ARM-M.  The concept is the same: Move the real-time stuff 
into hardware.

On Fri, Jun 19, 2020 at 12:45 PM R C <mailto:cjv...@gmail.com>> wrote:

On 6/19/20 1:34 PM, Chris Albertson wrote:
> A 4:1 reduction is possible with gears.  The sensor would be
mounted the
> same way but displaced off axis 24 mm then fitted with a 80T
gear and
> driven by a 20T gear that is itself driven by the drawbar.   I
would buy l
> gears (mod. 0.5 or Pi/2 mm pitch)  as printed gears are not
great in that
> tiny size.
>
> I think gears are good because they can be small mod 0.5 or even
smaller.
> Two minutes of hunting found this
> https://www.mcmaster.com/2662N31
> for $3 each.  This could be the "large" gear fixed to the sensor.
>
> There is "all the space in the world" above the spindle on the
mini mill
> but you need to preserve a way to get a wrench on the drawbar.
>
> The harder part is getting the encoder data into LinuxCNC/HAL. 
  It is
> easy if you have some Mesa cards.    More work if the data must
go in via
> USB.

I am still messing with reading quadrature encoder(s) on an RPI,
it can
be done.  I am doing that for a few reasons, one

is for adding something like that to a benchtop mill and lathe, the
other is to track the axes of a telescope mount that I

am building.

> On Fri, Jun 19, 2020 at 11:52 AM Ken Strauss
mailto:ken.stra...@gmail.com>> wrote:
>
>> I would like to add rigid tapping. Those are some inexpensive
encoders
>> except the top rated speed is 5000 rpm and I have a 1 rpm
spindle. Any
>> suggestions regarding suitable pulleys to reduce the speed
(perhaps 5:1)?
>> Will normal GT2 belts survive?
>>
>>> -Original Message-
>>> From: Chris Albertson [mailto:albertson.ch...@gmail.com
<mailto:albertson.ch...@gmail.com>]
>>> Sent: Friday, June 19, 2020 2:02 PM
>>> To: Enhanced Machine Controller (EMC)
>>> Subject: Re: [Emc-users] Universal spindle speed control for $7
>>>
>>> There is all the space I need to build an encoder for the HF
mill's
>>> spindle.  The sensor will fit above the drawbar.
>>>
>>> I'm thinking of using this sensor.  The shaft would point down and
>>> thesensor is aligned with an directly over the spindle.
>>>
ebay.com/itm/360-600P-R-Photoelectric-Incremental-Rotary-Encoder.
<http://ebay.com/itm/360-600P-R-Photoelectric-Incremental-Rotary-Encoder.>..
>>>
<https://www.ebay.com/itm/360-600P-R-Photoelectric-Incremental-Rotary-
>>> Encoder-5V-24V-AB-Two-Phases-
>>> Shaft/254214673272?hash=item3b30601378:g:AfUAAOSwQ0dcxosi>
>>>
>>> There is a cover over the spindle that is held on by
friction.     It
>> looks
>>> like the top on a can of spray paint.    I can make a
replacement that is
>>> held on by magnets.  Inside is the encoder that fits on top of the
>> drawbar.
>>> The sensor is fitted with a 17mm "socket"  that is light
friction fit to
>>> the top of the drawbar.
>>>
>>> In use, I&

Re: [Emc-users] Universal spindle speed control for $7

2020-06-19 Thread R C



On 6/19/20 1:34 PM, Chris Albertson wrote:

A 4:1 reduction is possible with gears.  The sensor would be mounted the
same way but displaced off axis 24 mm then fitted with a 80T gear and
driven by a 20T gear that is itself driven by the drawbar.   I would buy l
gears (mod. 0.5 or Pi/2 mm pitch)  as printed gears are not great in that
tiny size.

I think gears are good because they can be small mod 0.5 or even smaller.
Two minutes of hunting found this
https://www.mcmaster.com/2662N31
for $3 each.  This could be the "large" gear fixed to the sensor.

There is "all the space in the world" above the spindle on the mini mill
but you need to preserve a way to get a wrench on the drawbar.

The harder part is getting the encoder data into LinuxCNC/HAL.It is
easy if you have some Mesa cards.More work if the data must go in via
USB.


I am still messing with reading quadrature encoder(s) on an RPI, it can 
be done.  I am doing that for a few reasons, one


is for adding something like that to a benchtop mill and lathe, the 
other is to track the axes of a telescope mount that I


am building.




On Fri, Jun 19, 2020 at 11:52 AM Ken Strauss  wrote:


I would like to add rigid tapping. Those are some inexpensive encoders
except the top rated speed is 5000 rpm and I have a 1 rpm spindle. Any
suggestions regarding suitable pulleys to reduce the speed (perhaps 5:1)?
Will normal GT2 belts survive?


-Original Message-
From: Chris Albertson [mailto:albertson.ch...@gmail.com]
Sent: Friday, June 19, 2020 2:02 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Universal spindle speed control for $7

There is all the space I need to build an encoder for the HF mill's
spindle.  The sensor will fit above the drawbar.

I'm thinking of using this sensor.  The shaft would point down and
thesensor is aligned with an directly over the spindle.
ebay.com/itm/360-600P-R-Photoelectric-Incremental-Rotary-Encoder...


There is a cover over the spindle that is held on by friction. It

looks

like the top on a can of spray paint.I can make a replacement that is
held on by magnets.  Inside is the encoder that fits on top of the

drawbar.

The sensor is fitted with a 17mm "socket"  that is light friction fit to
the top of the drawbar.

In use, I'd remove the new cover and stick it on the side of the mill

using

the magnet, apply the wrench to the drawbar then replace the cover.

I am trying to decide if I want a 360 line or a 600 line encoder.

  Either

will send data too fast for a printer port with no Mesa card.   I might

put

a microcontroller in the cover and use a serial interface.   The plan is

to

get spindle speed control to run open-loop first.   I figure an open-loop
servo-controlled pot is at least as accurate as a human operator can do
with his fingers while listening to the noise.

My pendant project got a huge boost when I figured out I don't need to
build any hardware.   I can use an off the shelf X-box USB game
controller.  I already have a few of them.

On Fri, Jun 19, 2020 at 4:11 AM Gene Heskett 

wrote:

On Friday 19 June 2020 06:10:48 Roland Jollivet wrote:


I was going to suggest this at the start of the thread, but I thought
it would be considered too Heath Robinson..


And within its limitation of available torque to keep the tap turning,
and an encoder able to track to a 5 degree accuracy, I see no reason to
totally eliminate rigid tapping from its abilities. Even the little 200
watt hf mill should be able to turn an 0-80 or maybe even a 2mm tap.

The

lack of space in the head to build a decent encoder is far more of a
limitation than a speed controller such as this. Thats the main reason
my little hf never grew the ability to tap,  That controller/amplifier,
pulled out of the head and mounted in a 4x6x3" box so all the the hot
electronics was out of sight, proved to be a very high gain controller,
so high gain I was forced to rig an ammeter to tell me how hard it was
working so I could control the cost of fuses, there was otherwise no
slowdown to let the user know it was working too hard.

I eventually blew that controllers pass transistor, a simple powet
F.E.T., and in search of a suitable replacement, checked the bugs in an
out of spec pc supply from the junk box, found it was rated at 800

volts

instead of 200, 12 amps instead of 2.5, but otherwise looked the same.
So the consideration resolved to the driver transistor in the circuits
ability to switch the much higher gate capacitance that bug had to have
since switching speed is paramount. I put it in, think I had a

reservoir

of such bugs if it didn't work. I raised the fuse from 2.5 amps to 4.

That was over a decade back. I've blown the fuse 2 or 3 times since

with

the ammeter pegged, but its still there although the rest of the mill

is

in pieces,

Re: [Emc-users] AC power for stepper motor drivers?

2020-06-08 Thread R C

I 'rebuilt' a smaller lathe and mill, new steppers, drivers etc, but I 
wanted to keep the knobs/switches on the


enclosure working like they used to. So I just ended up doing everything 
with DC.  I only found out there are drivers that actually use DC (after 
I upgraded one of them), else I probably wouldn't even have kown.



Ron

On 6/8/20 8:15 PM, Chris Albertson wrote:

I just re-discovered Antek.  They make toroidal transformers for CNC and
high-end audio.  They also make unregulated DC power supplies using these
transformers.

If you need 5.6 amps at about 80 volts DC one of these will work
https://www.antekinc.com/ps-5n84-500w-84v-power-supply/   Note that it is
rated for continuous 5.9 amps even with 50 Hz mains.   This DC
supply costs about $120 but for about $60 you could buy an AC
transformer with the same power rating.

(I've just answered my own question)

I used to use this company's products when I was into tube-based audio.  It
is a US based company and they are easy to deal with.   They also make much
larger power supplies.  It took me a while to "change gears" from audio to
machine tools but both need big DC power.

On Mon, Jun 8, 2020 at 1:44 PM R C  wrote:


I have one that does both,  for a larger stepper motor.

It can take a bit of effort to find a DC PSU that can actually provide
5.5A the motor can 'pull', it's a lot easier

to get a transformer for one (my driver is 48VAC-80VAC OR 24VDC-110VDC)

Jus a transformer will provide the amps your 'pulling'  and of course
without any measures, spikes etc can happen. A switching

power supply has bit of protection there.  I think the driver probably
has some simple rectifier in it, I would expect much there.




On 6/8/20 2:05 PM, Chris Albertson wrote:

Some of the larger size Stepper motor drivers will use AC input power.

  I

assume all that is needed is a transformer that is rated for the required
current (and a fuse.)

Most people are using these Meanwell-style switching power supplies but

it

seems AC power might be better

Questions
Is there is the best type of transformer?   Is there a good supplier?
What about back EMF?   Not knowing how the driver works I wonder what
happens when the motor is breaking.  Can there be an overvoltage problem?



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Re: [Emc-users] AC power for stepper motor drivers?

2020-06-08 Thread R C


I have one that does both,  for a larger stepper motor.

It can take a bit of effort to find a DC PSU that can actually provide 
5.5A the motor can 'pull', it's a lot easier


to get a transformer for one (my driver is 48VAC-80VAC OR 24VDC-110VDC)

Jus a transformer will provide the amps your 'pulling'  and of course 
without any measures, spikes etc can happen. A switching


power supply has bit of protection there.  I think the driver probably 
has some simple rectifier in it, I would expect much there.





On 6/8/20 2:05 PM, Chris Albertson wrote:

Some of the larger size Stepper motor drivers will use AC input power.   I
assume all that is needed is a transformer that is rated for the required
current (and a fuse.)

Most people are using these Meanwell-style switching power supplies but it
seems AC power might be better

Questions
Is there is the best type of transformer?   Is there a good supplier?
What about back EMF?   Not knowing how the driver works I wonder what
happens when the motor is breaking.  Can there be an overvoltage problem?




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Re: [Emc-users] How to get data to HAL from USB, serial or socket?

2020-06-05 Thread R C

I have actually been wondering about the same/similar thing, on how to 
feed information into hall.


On 6/4/20 2:33 PM, Chris Albertson wrote:

I'd like to build a handheld pendant controller.   I have some ideas about
how it should work.  One thing I want is an LCD screen.   This could evolve
into a "smart pendant" that can do things like move along an arc, rather
than just one axis at a time.

I think the best physical interface from a handheld device to the computer
is USB.Is there a way to get data from USB to HAL?   I could use a USB
virtual serial port but then the question is getting serial port data to
HAL.

Maybe the best interface is wireless, so how to get data from a UNIX socket
to HAL?

Note that we don't need "hard" real-time to the computer.  Latency of a few
tens of milliseconds is acceptable for a human interface so this could be
done in userspace.  If so, then maybe all I need is a way to get data from
an arbitrary Linux application to HAL.

It just occurred to me that this "arbitrary Linux application" could be the
Apache webserver.  Then you run a browser on the tablet.

Summary:   How to move data from USB or serial or socket to HAL?




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Re: [Emc-users] Encoder HAL programming.


never done anything with those, and have a few RPIs lying around

On 5/25/20 1:27 PM, andy pugh wrote:

On Mon, 25 May 2020 at 20:15, R C  wrote:


I am actually trying to see how much I can push it by using a rpi for
that, that's about the same price.

An Arduino is possibly a better choice. You can get Nanos for about £5.




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Re: [Emc-users] Encoder HAL programming.

that's what I thought too, it's pretty expensive. (probably low 
production runs etc., obsolete?).



I am actually trying to see how much I can push it by using a rpi for 
that, that's about the same price.



Ron


On 5/25/20 1:07 PM, Jon Elson wrote:

On 05/25/2020 11:01 AM, R C wrote:
In the video I posted earlier (it's a year old)... the guy using that 
chip says it cost  him $40,  he showed it on line for about $28.


(and that's just for the LS7366R by itself.)


This just doesn't make sense anymore.  You can take a bottom of the 
line FPGA and put 4, 8 or maybe even dozens of quadrature counters in 
it, with digital filtering, latch on index and other features. The 
Spartan 3A chips I use are just over $10 each.


Jon


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Re: [Emc-users] Encoder HAL programming.

interesting, so how easy would it be to use a board/device like this in 
linux-cnc?


if those are just a few $$$  it would be fun to mess with.

On 5/25/20 3:39 AM, Chris Albertson wrote:

Yes, you can buy a hardware Quadrature chip.  But any modern
microcontroller like the STM32 will have hardware quadrature decoders.
The larger versions of the chip will have multiple quadrature decoders.
The chip will also have SPI.   These things cost under $1 or about $3 if
you want it on PCB ready to use.   If you buy the chip you need to design a
PCB.   I buy the microcontroller already on a PCB and in a usable form for
$3.

I like to place these not on some kind of large PCB near the main processor
but rather near the sensor.  This reduces the bulk of wire.   You can stick
the littlle computers where ever they are needed and then  snake one
(say) CANbus
cable around to connect each of them to power and data.

If you try to build a cape that does everything you find that you can't.
By "everything" I mean works with a PC, with a Pi4 and with a BBB and
connects steppers and servos and VFDs and linear scales. It is best to
just put a CAN bus or whatever on the main computer and nothing else.
  This is 100% "future proof" because every part can be swapped out.

These little boards have become by "go to" universal interface board.  They
cost $3 and have hardware pulse, PWM and quadrature support in hardware and
can talk over SPI I2C or USB.  They are small and cheap enough that you can
place them where ever they are needed.
ebay.com/itm/STM32F103C8T6...
<https://www.ebay.com/itm/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino-HOT/372276039369?epid=23002532325&hash=item56ad618ec9:g:VjoAAOSwkRJazxC6>

THe other design option is to use an FPGA.  That is what Mesa does and they
can put any reasonable number of counters and generaters in one FPGA but
then you have to route a ton of wires all back to that one chip.

Ideally you have just one thin cable going from controller to the machine.
  If you like those chips just glue on on each encoder and turn then encoder
into a serial interfaced device.  Or use a serial buss so 6 encoders can
share one cable.



On Mon, May 25, 2020 at 12:38 AM John Dammeyer 
wrote:


BTW,  Check out
https://lsicsi.com/datasheets/LS7366R.pdf
This device is interfaced via SPI and has a 32 bit quadrature counter
module.  If you go in the direction of Raspberry Pi with LinuxCNC a device
like this can provide the spindle information.  So if someone was thinking
of building a CNC cape for a Pi a device like this would be a good idea.
There are also devices from the same manufacturer that can change
quadrature into up/down pulses streams to use regular counters inside the
Pi.

John



-Original Message-
From: R C [mailto:cjv...@gmail.com]
Sent: May-24-20 6:01 PM
To: linuxcnc-users-list
Subject: Re: [Emc-users] Encoder HAL programming.


On 5/24/20 6:29 PM, andy pugh wrote:

On Mon, 25 May 2020 at 00:17, R C  wrote:


I have been following this thread.  I wrote some code that runs on an
RPI that can read a quadrature encoder, I have a few of them, with
different resolutions.

Is this something different to the normal LinuxCNC software encoder
that reads GPIO?
Is there some dedicated encoder counter hardware on the Pi?


Oh I am not running linux cnc on an rpi, I run it on a server "class"
machine.�� I was just curious about how these encoders work, and why
they didn't

work that well with my linux-cnc setup using a db25 BOB with the 2
benchtops I have.


So I decided to use an RPI (because it is easy to use GPIO pins to read
signals) and write some code to read these� encoder signals.



So I guess my answer is yes,� it is different from, what linux-cnc
running on a pi does (I would be surprised if it was similar)


I setup an RPI, hooked up a 2 line LCD display to it to display rpms,
wrote some interrupt driven code that reads the encoder and displays it
on the LCD. The idea is, I want

to try and see if I can read the encoder and then send signals back to
linux-cnc that it 'could handle".


So I have a 60ppr encoder,� 60 has a lot of dividers.� 2, 3, 4, 5, 6,
10, and 12� So if I can "transfer" a pulse with a consistent delay
exactly when the actual n-th pulse

comes in, I could turn a 60ppr� encoder into a 30, 20, 15, 12, 10, 6 or
5 ppr encoder by just skipping pulses,� while raising some GPIO pins,
that I connect to the BOB, when

I read a different set of GPIO pins directly from the encoder.



But as I said earlier,� I don't know a lot about the linux-cnc's
internals, and HAL, but it is something I am playing with to see if it
could work.


Ron



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Re: [Emc-users] Encoder HAL programming.

In the video I posted earlier (it's a year old)...  the guy using that 
chip says it cost  him $40,  he showed it on line for about $28.


(and that's just for the LS7366R by itself.)


https://www.youtube.com/watch?v=RLCPKa9SoF0

On 5/25/20 2:31 AM, Gene Heskett wrote:

On Monday 25 May 2020 03:35:05 John Dammeyer wrote:


BTW,  Check out
https://lsicsi.com/datasheets/LS7366R.pdf

Is cute, but the only thing it can do better than a mesa 7i90, is work at
5 volts. Both are s32 counters, but the mesa needs >3.3 volt
protections. What is its per unit cost?

And its the protections that run the price of a complete 7i90 solution
out of sight. But you also get a total of 72 i/o lines so you generally
can do a complete system for a multiaxis machine on just one of them.


This device is interfaced via SPI and has a 32 bit quadrature counter
module.  If you go in the direction of Raspberry Pi with LinuxCNC a
device like this can provide the spindle information.  So if someone
was thinking of building a CNC cape for a Pi a device like this would
be a good idea.  There are also devices from the same manufacturer
that can change quadrature into up/down pulses streams to use regular
counters inside the Pi.

But quadrature has one huge advantage over regular counters, you get both
speed AND  direction from every edge that goes by.

John


-Original Message-----
From: R C [mailto:cjv...@gmail.com]
Sent: May-24-20 6:01 PM
To: linuxcnc-users-list
Subject: Re: [Emc-users] Encoder HAL programming.

On 5/24/20 6:29 PM, andy pugh wrote:

On Mon, 25 May 2020 at 00:17, R C  wrote:

I have been following this thread.  I wrote some code that runs
on an RPI that can read a quadrature encoder, I have a few of
them, with different resolutions.

Is this something different to the normal LinuxCNC software
encoder that reads GPIO?
Is there some dedicated encoder counter hardware on the Pi?

Oh I am not running linux cnc on an rpi, I run it on a server
"class" machine.�� I was just curious about how these encoders work,
and why they didn't

work that well with my linux-cnc setup using a db25 BOB with the 2
benchtops I have.


So I decided to use an RPI (because it is easy to use GPIO pins to
read signals) and write some code to read these� encoder signals.



So I guess my answer is yes,� it is different from, what linux-cnc
running on a pi does (I would be surprised if it was similar)


I setup an RPI, hooked up a 2 line LCD display to it to display
rpms, wrote some interrupt driven code that reads the encoder and
displays it on the LCD. The idea is, I want

to try and see if I can read the encoder and then send signals back
to linux-cnc that it 'could handle".


So I have a 60ppr encoder,� 60 has a lot of dividers.� 2, 3, 4, 5,
6, 10, and 12� So if I can "transfer" a pulse with a consistent
delay exactly when the actual n-th pulse

comes in, I could turn a 60ppr� encoder into a 30, 20, 15, 12, 10, 6
or 5 ppr encoder by just skipping pulses,� while raising some GPIO
pins, that I connect to the BOB, when

I read a different set of GPIO pins directly from the encoder.



But as I said earlier,� I don't know a lot about the linux-cnc's
internals, and HAL, but it is something I am playing with to see if
it could work.


Ron



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Cheers, Gene Heskett



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Re: [Emc-users] Encoder HAL programming.

I actually saw a youtube video where someone was using this chip.  I 
believe he said it was like $28, and you'd still need something to read/run


it with. (also,  not running linux cnc on the pi,  the little raspberry 
pi project has nothing to do with my linux cnc machine, I just did that 
to read


the quadrature encoder.


Here's the video I found a while back: 
https://www.youtube.com/watch?v=RLCPKa9SoF0



Ron

On 5/25/20 1:35 AM, John Dammeyer wrote:

BTW,  Check out
https://lsicsi.com/datasheets/LS7366R.pdf
This device is interfaced via SPI and has a 32 bit quadrature counter module.  
If you go in the direction of Raspberry Pi with LinuxCNC a device like this can 
provide the spindle information.  So if someone was thinking of building a CNC 
cape for a Pi a device like this would be a good idea.  There are also devices 
from the same manufacturer that can change quadrature into up/down pulses 
streams to use regular counters inside the Pi.

John



-Original Message-----
From: R C [mailto:cjv...@gmail.com]
Sent: May-24-20 6:01 PM
To: linuxcnc-users-list
Subject: Re: [Emc-users] Encoder HAL programming.


On 5/24/20 6:29 PM, andy pugh wrote:

On Mon, 25 May 2020 at 00:17, R C  wrote:


I have been following this thread.  I wrote some code that runs on an
RPI that can read a quadrature encoder, I have a few of them, with
different resolutions.

Is this something different to the normal LinuxCNC software encoder
that reads GPIO?
Is there some dedicated encoder counter hardware on the Pi?


Oh I am not running linux cnc on an rpi, I run it on a server "class"
machine.�� I was just curious about how these encoders work, and why
they didn't

work that well with my linux-cnc setup using a db25 BOB with the 2
benchtops I have.


So I decided to use an RPI (because it is easy to use GPIO pins to read
signals) and write some code to read these� encoder signals.



So I guess my answer is yes,� it is different from, what linux-cnc
running on a pi does (I would be surprised if it was similar)


I setup an RPI, hooked up a 2 line LCD display to it to display rpms,
wrote some interrupt driven code that reads the encoder and displays it
on the LCD. The idea is, I want

to try and see if I can read the encoder and then send signals back to
linux-cnc that it 'could handle".


So I have a 60ppr encoder,� 60 has a lot of dividers.� 2, 3, 4, 5, 6,
10, and 12� So if I can "transfer" a pulse with a consistent delay
exactly when the actual n-th pulse

comes in, I could turn a 60ppr� encoder into a 30, 20, 15, 12, 10, 6 or
5 ppr encoder by just skipping pulses,� while raising some GPIO pins,
that I connect to the BOB, when

I read a different set of GPIO pins directly from the encoder.



But as I said earlier,� I don't know a lot about the linux-cnc's
internals, and HAL, but it is something I am playing with to see if it
could work.


Ron



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Re: [Emc-users] Encoder HAL programming.

2020-05-24 Thread R C



On 5/24/20 6:29 PM, andy pugh wrote:

On Mon, 25 May 2020 at 00:17, R C  wrote:


I have been following this thread.  I wrote some code that runs on an
RPI that can read a quadrature encoder, I have a few of them, with
different resolutions.

Is this something different to the normal LinuxCNC software encoder
that reads GPIO?
Is there some dedicated encoder counter hardware on the Pi?



Oh I am not running linux cnc on an rpi, I run it on a server "class" 
machine.   I was just curious about how these encoders work, and why 
they didn't


work that well with my linux-cnc setup using a db25 BOB with the 2 
benchtops I have.



So I decided to use an RPI (because it is easy to use GPIO pins to read 
signals) and write some code to read these  encoder signals.




So I guess my answer is yes,  it is different from, what linux-cnc 
running on a pi does (I would be surprised if it was similar)



I setup an RPI, hooked up a 2 line LCD display to it to display rpms, 
wrote some interrupt driven code that reads the encoder and displays it 
on the LCD. The idea is, I want


to try and see if I can read the encoder and then send signals back to 
linux-cnc that it 'could handle".



So I have a 60ppr encoder,  60 has a lot of dividers.  2, 3, 4, 5, 6, 
10, and 12  So if I can "transfer" a pulse with a consistent delay 
exactly when the actual n-th pulse


comes in, I could turn a 60ppr  encoder into a 30, 20, 15, 12, 10, 6 or 
5 ppr encoder by just skipping pulses,  while raising some GPIO pins, 
that I connect to the BOB, when


I read a different set of GPIO pins directly from the encoder.



But as I said earlier,  I don't know a lot about the linux-cnc's 
internals, and HAL, but it is something I am playing with to see if it 
could work.



Ron



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Re: [Emc-users] Encoder HAL programming.

2020-05-24 Thread R C


Hello,


I have been following this thread.  I wrote some code that runs on an 
RPI that can read a quadrature encoder, I have a few of them, with 
different resolutions.


I also have a few encoders that came with some stepper motors I got my 
hands on, still have to play with those to see what it is they exactly do.



I saw this thread about "HAL programming", I don't know much about 
linux-cnc/HAL, if anything, but is there some "general" interface so one 
could 'feed' linux cnc


data from an encoder?


I started  playing/messing with these things, because it seems that 
linux-cnc has a hard time keeping up with these encoders and there's not 
a whole lot I could find


about how to make a spindle encoder work with linux cnc


Ron


On 5/24/20 3:41 PM, John Dammeyer wrote:

The
http://linuxcnc.org/docs/html/examples/spindle.html#_spindle_feedback
document lists this example code with a footnote on the use of encoder.3

"In this example, we will assume that some encoders have already been issued to 
axes/joints 0, 1, and 2. So the next encoder available for us to attach to the spindle 
would be number 3. Your situation may differ."

The document isn't clear to me on this.  If I do not have encoders issued for 
axes/joints 0,1,2 then can the spindle use encoer.0?  Or are those numbers reserved 
for the existing axis anyway?  Which I guess doesn't make sense because then there 
would also have to be encoders for axis a,b & c and the spindle would start at 
6.  I've probably answered my own question.

But if the spindle encoder is declared in the hal file first, as encoder.0, does 
that make x,y & z then encoder.1, encoder.2 and encoder.3?

Or by default if encoders are used with x,y &z are they then by default 0,1 & 2?  
And even if declared in the hal file in a different order must be allocated as 0, 1 & 2?

Enquiring minds need to know.
Thanks
John


# add the encoder to HAL and attach it to threads.
loadrt encoder num_chan=1
addf encoder.update-counters base-thread
addf encoder.capture-position servo-thread

# set the HAL encoder to 100 pulses per revolution.
setp encoder.3.position-scale 100

# set the HAL encoder to non-quadrature simple counting using A only.
setp encoder.3.counter-mode true

# connect the HAL encoder outputs to LinuxCNC.
net spindle-position encoder.3.position => motion.spindle-revs
net spindle-velocity encoder.3.velocity => motion.spindle-speed-in
net spindle-index-enable encoder.3.index-enable <=> motion.spindle-index-enable

# connect the HAL encoder inputs to the real encoder.
net spindle-phase-a encoder.3.phase-A <= parport.0.pin-10-in
net spindle-phase-b encoder.3.phase-B
net spindle-index encoder.3.phase-Z <= parport.0.pin-11-in





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Re: [Emc-users] cloning hard drive to new SSD





On 04/23/2020 12:10 PM, Rafael Skodlar wrote:


Bravo. I'm horrified reading recommendations to use dd for cloning 
files on storage devices. dd copies fragmented files as is so you are 
messing new drive for performance issues from the get go.




btw:  you can "practice" dd with a usb stick or two, if you don't care 
what's on  them.


take an empty usb stick,  copy some stuff on it,  copy that stick with 
dd to a file,  take the other stick, use dd to copy it on the other.



USB sticks show up as similar devices in/dev   as /dev/sdx where  x is 
some letter.



Make sure they (the USB sticks) are not mounted,  and do NOT use the 
other existing device files in /dev,  except for the ones that showed up 
new and represent the USB stick






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Re: [Emc-users] cloning hard drive to new SSD



On 4/23/20 11:10 AM, Rafael Skodlar wrote:

On 2020-04-23 07:56, R C wrote:

well, you can do it with dd, but the details are tricky at times.


You are not just "cloning" a disk, like you used to copy a disk. I 
drive has multiple things, like an MBR, and


partitions and such. Most of the time to just clone a disk, copy it 
if you will, works, but what one should really


do is copy partitions, figure out how big they need to be. And then 
there's things like layout etc etc.



What clonezilla etc do, is use the same stuff, pretty much dd, except 
they have some "logic" in their software on how


why mess with installing that when core utilities and a bit of bash 
can do the same.




For system/Linux people that's easy to say.  For others it's like 
standing at the edge of a cliff and get the advise,  well  just don't 
make another step.  I don't think i works that way.






to copy those partitions, MBR/fat and all that. Some drives don't 
care about alignment for example, and work not that


optimal, others might not work like that.

A "fail safe" way to do it is use sync or so.  There are different 
ways to do that though.  If you do not want to "hammer"


the drive that is failing, you still create an img/iso, mount that 
and then create a disk by partitioning/formating it, and after


that you use the mounted image with sync or so to move the files to 
your new disk.



dd works really well for copying devices, especially if they are the 
same or very similar, or for copying a device to a file/iso/img


or from an "image file" to a CD/DVD or SSD memory. Mostly used for 
RapsberryPi and such.


dd is just a tool, very versatile and powerful, but as with all 
tools, you need to know the details on how to use it and for what.


Bravo. I'm horrified reading recommendations to use dd for cloning 
files on storage devices. dd copies fragmented files as is so you are 
messing new drive for performance issues from the get go.


The best use for dd is in computer forensics and virtualization 
environments for the same purpose or "deep troubleshooting" to find 
out why a VM has issues.


I mentioned rsync to be one of the best and most effective utilities 
for cloning locally or remotely in my experience. One option 
"--dry-run" allows you to see what will happen without making a big 
mistake if you are not careful.


There is another way to copy/clone files I learned in my Sun 
OS/Solaris days.


Drive 1, /dev/sdb mounted /tmp/disk1
Drive 2, /dev/sdc mounted /tmp/disk2

(cd /tmp/disk1; tar cfp - *) | (cd /tmp/disk2; tar xvf -)

* assumes all directories but you can just name a few for the process.

tar utility was always on all Unix systems, rsync was not. There is 
one more utility worth mentioning: cpio
You can change file ownership during file copy/clone process which is 
some times necessary.


I miss days when utilities mt and rmt were needed for files 
manipulation! It's magic to watch tape reels spin one way or the 
other. No silly G-code needed to spin reels or have the drive suck 
tape into vacuum chambers  ;-)





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Re: [Emc-users] cloning hard drive to new SSD

correct  BUT  if you don't do that you won't have an exact copy,  and if 
you have "so so" sectors, you might not be able to fix that  on


a "regular" copied drive.  Also, some of these copy utilities do not 
know why something is in a different order.


(older copy protection worked like that,  part of the trick was to stick 
a key in a fragmented file, that you read "sparse"..  BUT  if someone 
copied that


key,  the copy process would exactly do what you describe, de-fragment 
it, and consequently destroy the key.




Oh and nothing to be horrified about,  just don't write to the  old 
drive,  dd for sure doesn' as long as the drive is used in the if.



Also,  you can mount the drive as root,  and work with it as non root  
and it won't write on it.   that's 2 layers right there.



If you just want copies of the files and not an exact copy of the drive 
..  why not just copy all the files/directories you need?


On 4/23/20 12:15 PM, Jon Elson wrote:

On 04/23/2020 12:10 PM, Rafael Skodlar wrote:


Bravo. I'm horrified reading recommendations to use dd for cloning 
files on storage devices. dd copies fragmented files as is so you are 
messing new drive for performance issues from the get go.


Yes, this is true.  But, if you copy the partitions with cp, rsync or 
whatever, you get a more efficient file system, but grub will not be 
able to immediately load the kernel.  You then have to re-run grub
to link to where the kernel is now placed in the file system. This is 
doable, but a bit complicated.


Jon


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Re: [Emc-users] cloning hard drive to new SSD


well, you can do it with dd, but the details are tricky at times.


You are not just "cloning" a disk, like you used to copy a disk. I drive 
has multiple things, like an MBR, and


partitions and such. Most of the time to just clone a disk, copy it if 
you will, works, but what one should really


do is copy partitions, figure out how big they need to be. And then 
there's things like layout etc etc.



What clonezilla etc do, is use the same stuff, pretty much dd, except 
they have some "logic" in their software on how


to copy those partitions, MBR/fat and all that. Some drives don't care 
about alignment for example, and work not that


optimal, others might not work like that.

A "fail safe" way to do it is use sync or so.  There are different ways 
to do that though.  If you do not want to "hammer"


the drive that is failing, you still create an img/iso, mount that and 
then create a disk by partitioning/formating it, and after


that you use the mounted image with sync or so to move the files to your 
new disk.



dd works really well for copying devices, especially if they are the 
same or very similar, or for copying a device to a file/iso/img



dd is just a tool, very versatile and powerful, but as with all tools, 
you need to know the details on how to use it and for what.





On 4/23/20 1:26 AM, Glenn Edwards wrote:

I posed this same request to the group a couple weeks back.  I was going to
wait until I was successful with two clones before I reported my results,
but here is what I tried and what worked.  All my problems with cloning
arose from making a bootable HD.  dd failed to make a bootable drive for me
and so did clonezilla, at first.  Finally I made the target drive bootable
by using a LiveCD to install Ubuntu.  Then I used clonezilla to clone and
went into expert mode to instruct it to stay away from the boot partition.
That finally worked for me and I will try it on another drive this
weekend.  Also, there are two versions of Clonezilla, for old and new
hardware, so make sure you pick the right one.  BTW, all the advice about
the target drive being larger than the source: believe it.
-- --
Glenn


On Wed, Apr 22, 2020 at 8:59 PM nkp  wrote:


I use Clonezilla for this.
Great-great program!
https://clonezilla.org


23.04.2020 06:37, R C пишет:

if the new disk is smaller, unlikely nowadays, you might be able to
shrink it  image you created (if you did), effectively

it just truncates the file/iso and leave the empty space out.



On 4/22/20 9:31 PM, Jon Elson wrote:

On 04/22/2020 09:22 PM, andrew beck wrote:

Hey guys.

Just a quick question here

I recently heard some funny clanking noises in my old 2nd hand hard
drive
on my VMC and thought I better change it out and get a SSD in there.

I have a bunch of stuff loaded onto the hardrive for probe basic gui
and
other stuff and would like to clone the drive and keep everything.

I can manage a windows cloning I am just not sure if the process
will work
on a linux system.  I am using a crucial brand SSD and can download the
drive cloning software (it is rebadged acronis cloning software)



Well, there are two basic procedures.  As long as the new drive is at
least as large or larger than the old drive, then you can make an
absolute clone in a few hours with the dd command.

Best to boot off a live dvd, figure out the names of the two drives
and then

|dd  if=/dev/sdX of=/dev/sdY bs=64K conv=noerror,sync

if= is the input disk, of= is the output disk.  Replace X and Y with
the appropriate letters.Make REALLY sure you get
these right, or you will end up wiping the old disk.

To make sure, you can use fdisk /dev/sdX
and then type p to see the partition tables and makes of the drives.
That should tell you for sure which one has the linux file system,
and which one probably has no partitions set up.

The above procedure may not be real fast.

If the new drive is larger, you can then expand the Linux file system to
fill the disk.

If the new disk is smaller, then this won't work.


*** ONLY do the following if the new disk is smaller than the old one
***

You have to create
partitions with fdisk, make the file systems with mkfs and then copy
all the files with :

# mkdir /mnt/original
# mkdir /mnt/copy
# mount /dev/sdX#  /mnt/original
# mount /dev/sdY#  /mnt/copy
where X is for the original disk, Y is the copy, and # is the
partition number
# cp -rfa /mnt/original /mnt/copy
 and repeat this for all partitions (you don't need to copy the
 swapfile partition.  You create that with mkswap.

Now, the big issue here is that since files have been moved around on
the disk,
the grub loader will not know where to find them.  So, you have to
use the
live DVD system to run grub to update the loader to know where things
are.
The procedure is a bit involved, so I won't detail it unless you need to
go that route.

Jon

|


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Re: [Emc-users] cloning hard drive to new SSD

2020-04-22 Thread R C

if the new disk is smaller, unlikely nowadays, you might be able to 
shrink it  image you created (if you did), effectively


it just truncates the file/iso and leave the empty space out.



On 4/22/20 9:31 PM, Jon Elson wrote:

On 04/22/2020 09:22 PM, andrew beck wrote:

Hey guys.

Just a quick question here

I recently heard some funny clanking noises in my old 2nd hand hard 
drive

on my VMC and thought I better change it out and get a SSD in there.

I have a bunch of stuff loaded onto the hardrive for probe basic gui and
other stuff and would like to clone the drive and keep everything.

I can manage a windows cloning I am just not sure if the process will 
work

on a linux system.  I am using a crucial brand SSD and can download the
drive cloning software (it is rebadged acronis cloning software)


Well, there are two basic procedures.  As long as the new drive is at 
least as large or larger than the old drive, then you can make an 
absolute clone in a few hours with the dd command.


Best to boot off a live dvd, figure out the names of the two drives 
and then


|dd  if=/dev/sdX of=/dev/sdY bs=64K conv=noerror,sync

if= is the input disk, of= is the output disk.  Replace X and Y with
the appropriate letters.Make REALLY sure you get
these right, or you will end up wiping the old disk.

To make sure, you can use fdisk /dev/sdX
and then type p to see the partition tables and makes of the drives.
That should tell you for sure which one has the linux file system,
and which one probably has no partitions set up.

The above procedure may not be real fast.

If the new drive is larger, you can then expand the Linux file system to
fill the disk.

If the new disk is smaller, then this won't work.


*** ONLY do the following if the new disk is smaller than the old one ***

You have to create
partitions with fdisk, make the file systems with mkfs and then copy
all the files with :

# mkdir /mnt/original
# mkdir /mnt/copy
# mount /dev/sdX#  /mnt/original
# mount /dev/sdY#  /mnt/copy
   where X is for the original disk, Y is the copy, and # is the 
partition number

# cp -rfa /mnt/original /mnt/copy
    and repeat this for all partitions (you don't need to copy the
    swapfile partition.  You create that with mkswap.

Now, the big issue here is that since files have been moved around on 
the disk,
the grub loader will not know where to find them.  So, you have to use 
the
live DVD system to run grub to update the loader to know where things 
are.

The procedure is a bit involved, so I won't detail it unless you need to
go that route.

Jon

|


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Re: [Emc-users] cloning hard drive to new SSD

2020-04-22 Thread R C


do you have access to a unix box?  because there it's really easy to do.


Take the drive you want to "copy", connect it to a inix box and make 
sure it is not mounted.


Look up whatthe device isin, /dev.   with most drive it should be 
something like /dev/sdb  or sdc etc.  you can see it when you plug it 
in  AND


you can actually check it by mounting typically the first partition and 
check what's on it.



with the unmounted drive,  let's say it's /dev/sdx you do something like:


dd if=/dev/sdx of=/path/to/where/you/want/it/my-old-disk.iso bs=1M

and unplug the drive.

Now you have a disk image,  and you still have your unmodified drive,  
so you can try the next step until you have it right.



Take the new drive, hook it up make sure it is not mounted AND bigger 
(or at least the same size as your old drive.)



Let's say it's  /dev/sdy this time around when plugged in. then:


dd if=/path/to/where/you/want/it/my-old-disk.iso of=/dev/sdy BS=1M


and there it is.   If the drive is bigger you are left with unused 
space,  you can either make another partition, or you can expand one


of the partitions you put on there.  If you create another partion, 
you'll end up with something that looks like you have another drive, 
logically, not physically of course.




Ron

On 4/22/20 8:22 PM, andrew beck wrote:

Hey guys.

Just a quick question here

I recently heard some funny clanking noises in my old 2nd hand hard drive
on my VMC and thought I better change it out and get a SSD in there.

I have a bunch of stuff loaded onto the hardrive for probe basic gui and
other stuff and would like to clone the drive and keep everything.

I can manage a windows cloning I am just not sure if the process will work
on a linux system.  I am using a crucial brand SSD and can download the
drive cloning software (it is rebadged acronis cloning software)

anyway some help would be appreciated.


regards

Andrew

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Re: [Emc-users] latest/newest linuxcnc version

2020-04-04 Thread R C


Hi Andy,


ahh...  ok, didn't know that,  so I just install 2.7.14, and update it.  
It is on a network, so I can do that.



thanks!


Ron



On 4/4/20 11:41 AM, andy pugh wrote:

On Sat, 4 Apr 2020 at 17:57, R C  wrote:


the newest version of linuxcnc is 2.7.15, correct?
I don't seem to be able to find the download link, can someone post it here?

There isn't a new ISO file for the new version.
It should update automatically, or if not then manually using the
Synaptic package manager.

A hacky workaround if the machine is not on the network might be to
get the 2.7.15 .deb file for your OS and realtime kernel from
www.linuxcnc.org/dists
Then install it with sudo dpkg --install 




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[Emc-users] latest/newest linuxcnc version

2020-04-04 Thread R C


Hello all,


the newest version of linuxcnc is 2.7.15, correct?


I don't seem to be able to find the download link, can someone post it here?

(I don't see a download link in the 
http://linuxcnc.org/2020/01/03/LinuxCNC-2.7.15/ page where you can actually


get the iso, I am looking for the x86_64 or amd64 one.


thanks,


Ron



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Re: [Emc-users] Open source CNC architecture

2020-04-03 Thread R C


that's time travel,

you'd get scenarios like this though:

The replacement part you're thinking of since yesterday came in 2 weeks 
ago, we sent it back because


you weren't there to pick it up within a week. You still owe us for 
shipping though.




On 4/2/20 11:13 PM, Bari wrote:
Machining is old tech. I want to get my parts before I even know that 
I want them.


You study old tech while I have to fix the future.

Thanks.

On 4/2/20 10:51 PM, Rafael Skodlar wrote:
I study technologies while you watch sports... 



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Re: [Emc-users] Open source CNC architecture

2020-04-02 Thread R C


my 2 cnts;


I work in/with HPC, and run into that stuff all the time, and it is 
unavoidable.


Since HPCs run diskless, and boot in/from a network, we simply build a 
complete new image, (and keep


the older ones around). We never even update an image, we simply build a 
new one from scratch, since


an update on an existing system never works and it is easier to rebuild 
a repo (at least in RHEL it is).


Libraries etc, specific to applications either get relocated, or are 
merged with the OS ones on a virtual file system.



Of course that is pretty much undo-able, impractical, unaffordable to do 
at home, so what I do: I use different drives with


separate installs (I use these now very inexpensive CRU data trays to 
swap drives, and SSDs are really inexpensive now)



And indeed, let's not even get started on "rolling back" within an image.


containers; that's one of these things that don't seem to work 
consistently yet. I know people (at work) that are working


with it, developing in it, but I have not seen it work reliably/stable 
yet. It will definitely go there, but as of yet, at least


at scale, it is not working. (there are lots of issues that come down to 
latency/timing and rdma issues and we don't


even use real time kernels etc. most of what I do is based on RHEL and 
application specific RHEL 'flavors')



as I said, just my 2 cts,


Ron

On 4/2/20 4:14 AM, Przemek Klosowski wrote:

On Wed, Feb 19, 2020 at 1:51 AM Rafael Skodlar  wrote:


Think about LinuxCNC and it's packages. Using Slackware method you could
try to use different version of LCNC to see if it's good for your CNC
setup. If the new version fails (breaks your tool?) you could run
"cnc-admin script" to roll back, i.e. relink the app to previous version
and start it.

/opt/linuxcnc-v2.6/bin  <- binaries or scripts
/opt/linuxcnc-v2.6/etc  <- config files
...




/opt/linuxcnc-v2.7/bin
/opt/linuxcnc-v2.7/etc
...


What you suggest is not that simple. For starters, there are cross-package
dependencies, so in general you will have to carry various system libraries
required by each version. Then, modern programs use various forms of IPC,
so they need version specific versions of those IPC endpoints (things like
DBus, etc). IN the end, you can do it, but you replicate huge parts of the
OS. RedHat/Fedora tried to do Modularity, which is something like what you
propose except it turned out that you could have multi-version availability
but not multiversion installability (it was easy to switch versions, but
you could install only one). They put a lot of effort into making
dependencies work automatically, but in the end it turns out that lifecycle
management (patching/updating) is hard in a multi-version world: multiple
versions of multiple programs lead to combinatorial explosion of
dependencies and unresolvable conflicts when one program depends on ver. X
of something and another one on ver. Y. Currently Modularity is in retreat.

The technology to do that exists---containers like Docker or Podman. The
downside is that your system is now a mess of versions, and you need to
worry about patching and updating them. Containers provide a partial
solution to the Modularity problems---you can isolate such conflicts to
separate containers, but you still need to worry about lifecycle management.

If you are serious about those issues, read up on containers and
modularity---don't invent your own solutions, as a lot of people tried to
do it right and it's worth to learn from their experiences.

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Re: [Emc-users] CNC terminology

2020-03-28 Thread R C

actually,  I have been told there are combinations of parts produced  
those ways too.



It definitely is interesting.



On 3/28/20 9:21 PM, Chris Albertson wrote:

I don't think so. Form Labs, one of the big makers of resin printers call
their products "3D Printers".  The term 3D Print means more than just
FDM printing.

This is now widely used to make "real" parts  The fuel injectors in the
SpaceX rockets are printed.   "Printed" is the most common term and is used
for every process.

Even the low-cost, under $200 FDM printer can make usable parts.   I've
mead motor mounts for my CNC mill using PLA plastic on a $170 printer.  I
thought that later I'd remake then in metal but the plastic rigid enough
that I can't measure any deflection under load.  That said the plastic
does have a press-fit bronze bushing and a press fit thrust bearing.

One of the neat things is that we can use the same CAD files for both CNC
and 3D Printing.   So the part can be designed once and then made on
plastic to check fit and then if it work, cut metal.   There is a
convergence so it makes sense to  call one additive and the other
subtractive so we can think of it as just two ways to get the same end.



On Thu, Mar 26, 2020 at 2:01 PM R C  wrote:


I figured something like that...


On 3/26/20 1:34 PM, Bari wrote:


The term 3D printing also used to be a blanket term until it was
hijacked by the media and marketers to only mean CNC glue gun types of
3D printers aka FDM/FFF.



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Re: [Emc-users] CNC terminology


I figured something like that...


On 3/26/20 1:34 PM, Bari wrote:

Additive manufacturing is a blanket term as was 3D printing.

The term 3D printing also used to be a blanket term until it was 
hijacked by the media and marketers to only mean CNC glue gun types of 
3D printers aka FDM/FFF.


On 3/26/20 10:17 AM, R C wrote:

3D printing is called "Additive Manufacturing" just

to make it sound better



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Re: [Emc-users] CNC terminology




On 3/26/20 12:45 PM, Gene Heskett wrote:

On Thursday 26 March 2020 13:14:45 Stuart Stevenson wrote:


For years when someone has asked "What do you make?" my answer has
been "chips". You just get the raw material and make chips out of
everything that is not part.

Simple concept.

Rather like the sculptor standing next to 30ton block of granite saying
he's removing anything that doesn't look like an elephant.



sounds like it.



On Thu, Mar 26, 2020, 11:35 AM Chris Albertson


wrote:1

On Thu, Mar 26, 2020 at 8:19 AM R C  wrote:

Hello group/list,


So I am at home most of the time, working from home, like most of
us probably, but since I can't really do my job from home

I have been directed to look into things like "Additive
Manufacturing", g-codes etc etc...


I was just thinking (ok ok ..  I am bored...)  But if terminology
is buffed up and 3D printing is called "Additive Manufacturing"
just

to make it sound better,  maybe we should start calling CNC
machining "Subtractive Manufacturing", or has that already
happened?

Yes, that has already happend, years ago. What I would do to
look into 3D printing is buy one of the less then $200 printers and
make parts.  A great project is maybe a robot or a small CNC machine
tool made from plastic parts.  You learn best when you have a
project that pushes your skills just a little.

You can also combine additive and subtrctive methods.  for example
print, a part then treat it as casting and clean it up on a mill or
lathe.   Either you need an expensive printer that can print metal
or you print a mold in plastic then sand cast it, then machine it.
There is quite a lot to exlore at the ntersection of adding and
subtracting.Another is printing fixtures for machining.  Plastic
works well for holding and clamping odd-shape metal parts


Ron



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--

Chris Albertson
Redondo Beach, California

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Cheers, Gene Heskett



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Re: [Emc-users] CNC terminology

that's what a famous ancient sculptur used to say.   The scupture is 
already in there, I just remove the pieces that are not sculpture.



On 3/26/20 11:14 AM, Stuart Stevenson wrote:

For years when someone has asked "What do you make?" my answer has been
"chips". You just get the raw material and make chips out of everything
that is not part.

On Thu, Mar 26, 2020, 11:35 AM Chris Albertson 
wrote:


On Thu, Mar 26, 2020 at 8:19 AM R C  wrote:


Hello group/list,


So I am at home most of the time, working from home, like most of us
probably, but since I can't really do my job from home

I have been directed to look into things like "Additive Manufacturing",
g-codes etc etc...


I was just thinking (ok ok ..  I am bored...)  But if terminology is
buffed up and 3D printing is called "Additive Manufacturing" just

to make it sound better,  maybe we should start calling CNC machining
"Subtractive Manufacturing", or has that already happened?


Yes, that has already happend, years ago. What I would do to look into
3D printing is buy one of the less then $200 printers and make parts.  A
great project is maybe a robot or a small CNC machine tool made from
plastic parts.  You learn best when you have a project that pushes your
skills just a little.

You can also combine additive and subtrctive methods.  for example print, a
part then treat it as casting and clean it up on a mill or lathe.   Either
you need an expensive printer that can print metal or you print a mold in
plastic then sand cast it, then machine it.   There is quite a lot to
exlore at the ntersection of adding and subtracting.Another is printing
fixtures for machining.  Plastic works well for holding and clamping
odd-shape metal parts




Ron



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Chris Albertson
Redondo Beach, California

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Re: [Emc-users] CNC terminology



On 3/26/20 10:33 AM, Chris Albertson wrote:

On Thu, Mar 26, 2020 at 8:19 AM R C  wrote:


Hello group/list,


So I am at home most of the time, working from home, like most of us
probably, but since I can't really do my job from home

I have been directed to look into things like "Additive Manufacturing",
g-codes etc etc...


I was just thinking (ok ok ..  I am bored...)  But if terminology is
buffed up and 3D printing is called "Additive Manufacturing" just

to make it sound better,  maybe we should start calling CNC machining
"Subtractive Manufacturing", or has that already happened?


Yes, that has already happend, years ago. What I would do to look into
3D printing is buy one of the less then $200 printers and make parts.  A
great project is maybe a robot or a small CNC machine tool made from
plastic parts.  You learn best when you have a project that pushes your
skills just a little.

You can also combine additive and subtrctive methods.  for example print, a
part then treat it as casting and clean it up on a mill or lathe.   Either
you need an expensive printer that can print metal or you print a mold in
plastic then sand cast it, then machine it.   There is quite a lot to
exlore at the ntersection of adding and subtracting.Another is printing
fixtures for machining.  Plastic works well for holding and clamping
odd-shape metal parts


actually I have been thinking about buying a 3D pinter.  However I 
wanted to finish (and start working with) a sherline mill and lathe that 
were given


to me years ago (they came in a Paxton-Patterson enclosure).

I have done some robotics, did teach an extra curricular class on it, 
but that was more about sensors measuring things etc.



I like playing with that stuff, and I am tying to figure out how to do 
some things, some of you have been very helpful  in particular one guy 
(his name is Phill from here)


I have some colleagues doing that, but before embarking on 3D printing, 
I just want a "pile" of projects of my workbench








Ron



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[Emc-users] CNC terminology