Re: [Emc-users] Setting up two home switches on Y

[Frank Tkalcevic]

> I think that the problem is that you have y2-step in the Joint3
> section, but in the area where you are connecting the parallel port
> pins, both sets of step/dir outputs are netted to the ystep. So they
> move at exactly the same speed and at the same time.

And that is easy to test.  When you start axis, you should be in Joint mode.  
You can use the keyboard to jog each joint... 

Left/right - joint 0
Up/down - joint 1
PgUp/PgDn - joint 2
[/] - joint 3

(or use the buttons on the Axis UI)

Just jog your y1/y2 axis slowly.



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Re: [Emc-users] Setting up two home switches on Y

[andy pugh]

On Mon, 14 Sep 2020 at 21:52, Dave Matthews  wrote:

> Looking closer at the DRO on the screen I can see that the second Y
> axis is counting down looking for home but is not moving.
>
> I racked the gantry and tested to see if it would unrack.  What I
> found is that the new switch is ignored.

I am fully understanding how both these observations can be true at
the same time.

If the second Y does not move, how do you know the home switch is ignored?

I think that the problem is that you have y2-step in the Joint3
section, but in the area where you are connecting the parallel port
pins, both sets of step/dir outputs are netted to the ystep. So they
move at exactly the same speed and at the same time.

--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] cura can override if .stl says thinner walls?

[Gene Heskett]

On Monday 14 September 2020 14:21:50 Gene Heskett wrote:

> Greetings all 3d printer users;
>
> I just had my ender 3 pro render a flexgear in TPU, set for 4mm walls
> because I wanted more rigidity out of TPU.  PETG actslike its flexble
> enough, but still fails, breaking the splined portion off at the
> bottom of the splines.
>
> But I got walls about 1mm thick, and the usual way too much
> flexibility for any real torque.
>
> Can cura override your recipe if the .stl says thats too thick? It
> seems to ignore a 4.00 mm wall cmd. but does show it thicker if I tell
> it inner walls are 4,00 mm. I guess I'll find out in about 6 hours
> when it gets to building the upper wall.

Well, it got there but laid up an almost random mess for nearly 5.5 hours 
doing it. That totally blew cura's mind.

Left out any real bridge between the roof of the base and the rising 
wall, and left half an ounce of loose nozzle ejecta hanging down the 
outside in loops, screwed up the fill at the base to plate contact. A 
mess not worthy of finishing so I didn't.  The only thing I learned was 
that the base, supposedly to fit in a 35mm bearing, was about 34.9, so I 
added nominally .1 to both x and y scales to make that fit a bit better.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Setting up two home switches on Y

[Gene Heskett]

On Monday 14 September 2020 17:55:47 Peter C. Wallace wrote:

> On Mon, 14 Sep 2020, Gene Heskett wrote:
> > Date: Mon, 14 Sep 2020 17:40:36 -0400
> > From: Gene Heskett 
> > Reply-To: "Enhanced Machine Controller (EMC)"
> > 
> > To: emc-users@lists.sourceforge.net
> > Subject: Re: [Emc-users] Setting up two home switches on Y
> >
> > On Monday 14 September 2020 17:16:36 andy pugh wrote:
> >> On Mon, 14 Sep 2020 at 20:52, Gene Heskett 
> >
> > wrote:
> >>> One of the rules for the net command is that only the first of
> >>> that name in your hal file, is allowed to be an input.
> >>
> >> That's not true. They can be allocated in any order, but only one
> >> pin in the net can be a "writer". All the others must be readers.
> >> (except for the bidirectional index-enable pins)
> >
> > I got bit by that, and was told that, probably a decade back.  Now I
> > guess it either does pay attention to the arrow pairs, or looks at
> > arg2 to see if its input or output?
> >
> > Cheers, Gene Heskett
>
> The arrows dont do anything nor is the order of any importance
>
> In fact there is no issue with making an undriven signal (all hal
> input pins) Though I believe one of the hal file parsing utilities can
> check for undriven signals
>
> AFAIK signals are stored in memory locations that connected hal input
> pins read from and hal output pins write to (so more than one writer
> is disallowed)
>
Thank you Peter.
>
> Peter Wallace
> Mesa Electronics
>
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Setting up two home switches on Y

[Peter C. Wallace]

On Mon, 14 Sep 2020, Gene Heskett wrote:


Date: Mon, 14 Sep 2020 17:40:36 -0400
From: Gene Heskett 
Reply-To: "Enhanced Machine Controller (EMC)"

To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Setting up two home switches on Y

On Monday 14 September 2020 17:16:36 andy pugh wrote:


On Mon, 14 Sep 2020 at 20:52, Gene Heskett 

wrote:

One of the rules for the net command is that only the first of that
name in your hal file, is allowed to be an input.


That's not true. They can be allocated in any order, but only one pin
in the net can be a "writer". All the others must be readers.
(except for the bidirectional index-enable pins)


I got bit by that, and was told that, probably a decade back.  Now I
guess it either does pay attention to the arrow pairs, or looks at arg2
to see if its input or output?

Cheers, Gene Heskett


The arrows dont do anything nor is the order of any importance

In fact there is no issue with making an undriven signal (all hal input pins)
Though I believe one of the hal file parsing utilities can check for undriven 
signals


AFAIK signals are stored in memory locations that connected hal input pins read 
from and hal output pins write to (so more than one writer is disallowed)



Peter Wallace
Mesa Electronics


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Re: [Emc-users] Setting up two home switches on Y

[Gene Heskett]

On Monday 14 September 2020 17:16:36 andy pugh wrote:

> On Mon, 14 Sep 2020 at 20:52, Gene Heskett  
wrote:
> > One of the rules for the net command is that only the first of that
> > name in your hal file, is allowed to be an input.
>
> That's not true. They can be allocated in any order, but only one pin
> in the net can be a "writer". All the others must be readers.
> (except for the bidirectional index-enable pins)

I got bit by that, and was told that, probably a decade back.  Now I 
guess it either does pay attention to the arrow pairs, or looks at arg2 
to see if its input or output?

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Setting up two home switches on Y

[Gene Heskett]

On Monday 14 September 2020 17:16:36 andy pugh wrote:

> On Mon, 14 Sep 2020 at 20:52, Gene Heskett  
wrote:
> > One of the rules for the net command is that only the first of that
> > name in your hal file, is allowed to be an input.
>
> That's not true. They can be allocated in any order, but only one pin
> in the net can be a "writer". All the others must be readers.
> (except for the bidirectional index-enable pins)


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Setting up two home switches on Y

[andy pugh]

On Mon, 14 Sep 2020 at 20:52, Gene Heskett  wrote:
>
> One of the rules for the net command is that only the first of that name
> in your hal file, is allowed to be an input.

That's not true. They can be allocated in any order, but only one pin
in the net can be a "writer". All the others must be readers.
(except for the bidirectional index-enable pins)

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Setting up two home switches on Y

[Dave Matthews]

On Mon, Sep 14, 2020 at 3:52 PM andy pugh  wrote:
>
> On Mon, 14 Sep 2020 at 20:19, Dave Matthews  wrote:
>
> > Almost there.  There isn't a gantry.hal file on github that I can find
> > to reference.
>
> https://github.com/LinuxCNC/linuxcnc/blob/master/lib/hallib/gantrysim.hal
> Maybe?
>
> >   When I start LinuxCNC I
> > get an exit because ypos-cmd, ypos-fb, ystep and yenable have already
> > been assigned
>
> Try cloning them as y2*-*
> (the sample HAL above uses joint0 to joint3, which might be clearer.
>
Adding the prefix got things moving.  When I start Axis comes up with
four numbered radio buttons for the joints.  I hit home all and it
does it's thing and the GUI changes to X Y Z radio buttons.  I cannot
job Y without homing the others jog without homing.  Good so far.

Looking closer at the DRO on the screen I can see that the second Y
axis is counting down looking for home but is not moving.

I racked the gantry and tested to see if it would unrack.  What I
found is that the new switch is ignored.  Using Hal Meter I can watch
it toggle.

I tried with kinstype=BOTH like the example and also with kinstype=b
like the docs call out.  No change.

It is like the machine knows it has four joints but is acting like it
should still home on only one of the Y joints.  I do have homing set
to -2, sequence is Z X Y.

.ini and .hal files are attached.

Dave


4HomingSwitchesWithLaser.ini
Description: application/wine-extension-ini


4HomingSwitchesWithLaser.hal
Description: Binary data
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Re: [Emc-users] Setting up two home switches on Y

[Dave Matthews]

On Mon, Sep 14, 2020 at 3:52 PM Gene Heskett  wrote:
>
> On Monday 14 September 2020 15:16:04 Dave Matthews wrote:
>
> > On Fri, Sep 11, 2020 at 5:16 PM andy pugh  wrote:
>
> One of the rules for the net command is that only the first of that name
> in your hal file, is allowed to be an input.  Re-use of a given name is
> assumed to be a link to send that signal to another target, like your
> joint 3 stuff.  A way to send a given signal to many places.  Your
> net ystep lines arrows are backwards IOW.  And its confusing because at
> one point, those <= and => were ignored. only there to help us humans
> understand.  But with two-pass enabled, I'm not so sure, so someone
> should clarify that.
>

The arrows are exactly as Stepgen created them.

Dave


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Re: [Emc-users] Setting up two home switches on Y

[Gene Heskett]

On Monday 14 September 2020 15:16:04 Dave Matthews wrote:

> On Fri, Sep 11, 2020 at 5:16 PM andy pugh  wrote:
> > On Fri, 11 Sep 2020 at 21:18, Dave Matthews  wrote:
> > > The examples that I have found are for Mesa cards and seem to have
> > > a lot of stuff in them that I don't have in my .ini and .hal
> > > files.
> >
> > Have you looked at the supplied sim-axis-gantry config?
> >
> > > Any hints on where I can find the docs on editing the ini and hal
> > > files to add the second Y home switch and having 4 joint homing?
> >
> > The important parts are the [KINS] section and the homing sequence
> > numbers for the joints here:
> > https://github.com/LinuxCNC/linuxcnc/blob/master/configs/sim/axis/ga
> >ntry/gantry.ini
> >
> > Then you just need to connect the two joint.N.home-sw-in pins to the
> > relevant parport pins in the HAL file.
> >
> > (I wouldn't suggest looking at the simulated-gantry-home HAL file,
> > that is almost entirely related to _simulating_ home switches.)
>
> Almost there.  There isn't a gantry.hal file on github that I can find
> to reference.  I set up the Kinematics and added the new switch being
> careful to not have a name conflict.  I copy/pasted the joint for the
> current Y axis (JOINT_1) creating JOINT_3.  I then replaced the 1 in
> that section with 3 to create the new joint.  When I start LinuxCNC I
> get an exit because ypos-cmd, ypos-fb, ystep and yenable have already
> been assigned during the JOINT_1 setup.  With those lines commented
> out I can get a startup and 4 joints showing on the screen.
>
> The relevant hal section, a copy of JOINT_1 is:
> setp stepgen.3.position-scale [JOINT_3]SCALE
> setp stepgen.3.steplen 1
> setp stepgen.3.stepspace 0
> setp stepgen.3.dirhold 65000
> setp stepgen.3.dirsetup 65000
> setp stepgen.3.maxaccel [JOINT_3]STEPGEN_MAXACCEL
> net ypos-cmd joint.3.motor-pos-cmd => stepgen.3.position-cmd
> net ypos-fb stepgen.3.position-fb => joint.3.motor-pos-fb
> net ystep <= stepgen.3.step
> net ydir <= stepgen.3.dir
> net yenable joint.3.amp-enable-out => stepgen.3.enable
> net home-y-right => joint.3.home-sw-in
>
> I am not finding the place in the docs telling me what to do with
> these lines.  Delete them?   Rename the variables?  I didn't do this
> as I couldn't find other references which leads me to think they may
> be fixed names used by the code.
>
> Dave

One of the rules for the net command is that only the first of that name 
in your hal file, is allowed to be an input.  Re-use of a given name is 
assumed to be a link to send that signal to another target, like your 
joint 3 stuff.  A way to send a given signal to many places.  Your 
net ystep lines arrows are backwards IOW.  And its confusing because at 
one point, those <= and => were ignored. only there to help us humans 
understand.  But with two-pass enabled, I'm not so sure, so someone 
should clarify that.

So scan the file, and make sure the first use of a signals name, assigns 
the source of that signal.
>
>
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Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] Setting up two home switches on Y

[andy pugh]

On Mon, 14 Sep 2020 at 20:19, Dave Matthews  wrote:

> Almost there.  There isn't a gantry.hal file on github that I can find
> to reference.

https://github.com/LinuxCNC/linuxcnc/blob/master/lib/hallib/gantrysim.hal
Maybe?

>   When I start LinuxCNC I
> get an exit because ypos-cmd, ypos-fb, ystep and yenable have already
> been assigned

Try cloning them as y2*-*
(the sample HAL above uses joint0 to joint3, which might be clearer.

> I am not finding the place in the docs telling me what to do with
> these lines.  Delete them?   Rename the variables?

The net names are your choice, the pin names have to exist.

The net name is the first thing after the "net" command.


-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] Setting up two home switches on Y

[Dave Matthews]

On Fri, Sep 11, 2020 at 5:16 PM andy pugh  wrote:
>
> On Fri, 11 Sep 2020 at 21:18, Dave Matthews  wrote:
>
> > The examples that I have found are for Mesa cards and seem to have a
> > lot of stuff in them that I don't have in my .ini and .hal files.
>
> Have you looked at the supplied sim-axis-gantry config?
>
> > Any hints on where I can find the docs on editing the ini and hal
> > files to add the second Y home switch and having 4 joint homing?
>
> The important parts are the [KINS] section and the homing sequence
> numbers for the joints here:
> https://github.com/LinuxCNC/linuxcnc/blob/master/configs/sim/axis/gantry/gantry.ini
>
> Then you just need to connect the two joint.N.home-sw-in pins to the
> relevant parport pins in the HAL file.
>
> (I wouldn't suggest looking at the simulated-gantry-home HAL file,
> that is almost entirely related to _simulating_ home switches.)

Almost there.  There isn't a gantry.hal file on github that I can find
to reference.  I set up the Kinematics and added the new switch being
careful to not have a name conflict.  I copy/pasted the joint for the
current Y axis (JOINT_1) creating JOINT_3.  I then replaced the 1 in
that section with 3 to create the new joint.  When I start LinuxCNC I
get an exit because ypos-cmd, ypos-fb, ystep and yenable have already
been assigned during the JOINT_1 setup.  With those lines commented
out I can get a startup and 4 joints showing on the screen.

The relevant hal section, a copy of JOINT_1 is:
setp stepgen.3.position-scale [JOINT_3]SCALE
setp stepgen.3.steplen 1
setp stepgen.3.stepspace 0
setp stepgen.3.dirhold 65000
setp stepgen.3.dirsetup 65000
setp stepgen.3.maxaccel [JOINT_3]STEPGEN_MAXACCEL
net ypos-cmd joint.3.motor-pos-cmd => stepgen.3.position-cmd
net ypos-fb stepgen.3.position-fb => joint.3.motor-pos-fb
net ystep <= stepgen.3.step
net ydir <= stepgen.3.dir
net yenable joint.3.amp-enable-out => stepgen.3.enable
net home-y-right => joint.3.home-sw-in

I am not finding the place in the docs telling me what to do with
these lines.  Delete them?   Rename the variables?  I didn't do this
as I couldn't find other references which leads me to think they may
be fixed names used by the code.

Dave


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Re: [Emc-users] ot: welders

[Gene Heskett]

On Monday 14 September 2020 13:33:59 grumpy--- via Emc-users wrote:

> On Mon, 14 Sep 2020, Jon Elson wrote:
> > On 09/14/2020 10:42 AM, grumpy--- via Emc-users wrote:
> >> i'm retired
> >> just look'n to weld steel at home
> >> a stick welder
> >> for about 20 years i was attached at the hip to a lincoln stovepipe
> >> i've tried a couple of the cheap inverters and they are better than
> >> noth'n just barely
> >> i know have'n a motor-generator unit at home is out of the question
> >> but surely something comes close
> >
> > I have done some stick welding, but the flux fumes really got to me.
> > I finally bought a Lincoln Square Wave TIG 250 on eBay and it has
> > been fantastic.
> > I can now weld in the basement and nobody even knows I'm doing it.
> > TIG is a lot
> > slower than stick, but you can actually see what you are doing
> > without the cloud of flux smoke,
> > and you can weld aluminum and copper, too!
> >
> > You can likely find a decent TIG machine that isn't too expensive,
> > and give your lungs a break.
>
> i've done my share of tig on stainless tubing
> not very good on heavy material
> where i worked was a plant that used ammonia refrigeration
> my lungs were fried decades ago
>
Granted, ammonia is not at all healthy, but if you ever come in contact 
with a system that uses sulfur dioxide you are very lucky to have 
survived it. Sulfur dioxide is a very active and unstable gas, borrowing 
an oxygen atom from where ever it can get it to become sulfur trioxide 
and your lungs are a great source of the moisture to supply the oxygen 
atom to do this chemical magic.  Another more common name for sulfur 
trioxide is sulfuric acid.  Not a pleasant way to go out, and a lot of 
people did back in the days of the monitor top home refrigerator which 
used it, likewise the propane fired mobile home/camper fridges yet 
today.  One molecule of water in such a system kept being recycled into 
acid and eventually ate a hole in the plumbing, in 20 years or so. Its a 
very efficient refrigeration gas, beating ammonia and all the freon's.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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[Emc-users] cura can override if .stl says thinner walls?

[Gene Heskett]

Greetings all 3d printer users;

I just had my ender 3 pro render a flexgear in TPU, set for 4mm walls 
because I wanted more rigidity out of TPU.  PETG actslike its flexble 
enough, but still fails, breaking the splined portion off at the bottom 
of the splines.

But I got walls about 1mm thick, and the usual way too much flexibility 
for any real torque.

Can cura override your recipe if the .stl says thats too thick? It seems 
to ignore a 4.00 mm wall cmd. but does show it thicker if I tell it 
inner walls are 4,00 mm. I guess I'll find out in about 6 hours when it 
gets to building the upper wall.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] ot: welders

[grumpy--- via Emc-users]

On Mon, 14 Sep 2020, Jon Elson wrote:


On 09/14/2020 10:42 AM, grumpy--- via Emc-users wrote:

i'm retired
just look'n to weld steel at home
a stick welder
for about 20 years i was attached at the hip to a lincoln stovepipe
i've tried a couple of the cheap inverters and they are better than noth'n
just barely
i know have'n a motor-generator unit at home is out of the question
but surely something comes close

I have done some stick welding, but the flux fumes really got to me.
I finally bought a Lincoln Square Wave TIG 250 on eBay and it has been 
fantastic.
I can now weld in the basement and nobody even knows I'm doing it. TIG is a 
lot
slower than stick, but you can actually see what you are doing without the 
cloud of flux smoke,

and you can weld aluminum and copper, too!

You can likely find a decent TIG machine that isn't too expensive, and give 
your lungs a break.


i've done my share of tig on stainless tubing
not very good on heavy material
where i worked was a plant that used ammonia refrigeration
my lungs were fried decades ago


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Re: [Emc-users] ot: welders

[Kirk Wallace]

On 9/14/20 7:10 AM, grumpy--- via Emc-users wrote:

this list is home to a bunch of very sharp folks
and i don't intend to drag y'all too far off course
i am look'n for a welder
does anyone know of a good mail'n list for non-pro welders


snip ...

It isn't exactly what you asked for but might get you started in finding 
a amateur welding mail list.



IMHO: ...


https://youtu.be/zZAfNKx25_A


Welding Tips and Tricks (also on Patreon)


https://www.youtube.com/channel/UCqq70AnPkj4-UApS_m_6mPw


I bought this one but only used it a few times so far:


https://primeweld.com/products/tig-225x-ac-dc-tig-welder





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Re: [Emc-users] G93 minimum value/behaviour

[Gene Heskett]

On Monday 14 September 2020 11:51:51 andy pugh wrote:

> On Mon, 14 Sep 2020 at 16:27, Robert Ellenberg  
wrote:
> > I think a smarter approach would be to check if the effective feed
> > rate is too small (like below what a machine can actually execute)
>
> Is there any physical limit to how slowly an axis can move? We nearly
> all own a device that moves less than 1" per hour...

As a C.E.T., I can see where it could be a carryover from the servo 
world, where there would be a minimum hz you could feed an AC induction 
servo with, but I'd expect those have by now, all died of old age. Or 
burnups holding up a vertical axis with worn out brake shoes. Hard steel 
with PM armatures shouldn't have a problem with that as long as the 
cooling is adequate and the currant is limited to the FLA on the 
nameplate.  With the FLA current limit set, I can run my 1 horse AC 
induction spindle motor at well below 10 hz for an hour and still lay a 
hand on it.

Other than that consideration, a minimum speed simply has no reason to 
exit in linuxcnc.  IMO of course.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
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Re: [Emc-users] ot: welders

[Jon Elson]

On 09/14/2020 10:42 AM, grumpy--- via Emc-users wrote:

i'm retired
just look'n to weld steel at home
a stick welder
for about 20 years i was attached at the hip to a lincoln 
stovepipe
i've tried a couple of the cheap inverters and they are 
better than noth'n

just barely
i know have'n a motor-generator unit at home is out of the 
question

but surely something comes close
I have done some stick welding, but the flux fumes really 
got to me.
I finally bought a Lincoln Square Wave TIG 250 on eBay and 
it has been fantastic.
I can now weld in the basement and nobody even knows I'm 
doing it. TIG is a lot
slower than stick, but you can actually see what you are 
doing without the cloud of flux smoke,

and you can weld aluminum and copper, too!

You can likely find a decent TIG machine that isn't too 
expensive, and give your lungs a break.


Jon


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Re: [Emc-users] G93 minimum value/behaviour

[Dewey Garrett]

A lower bound on f values for inverse_time mode (g93)
has been in the code forever as far as i can tell
but may not be documented:

comment in interp_convert.cc:

"In inverse time feed mode, a lower bound of 0.1 is placed on the feed
rate so that the feed rate is never set to zero. If the destination
point is the same as the current point, the feed rate would be
calculated as zero otherwise."

Ref: 
https://github.com/LinuxCNC/linuxcnc/blob/2.8/src/emc/rs274ngc/interp_convert.cc#L4442


and implemented here for straight and arc moves:
https://github.com/LinuxCNC/linuxcnc/blob/2.8/src/emc/rs274ngc/interp_inverse.cc#L65
https://github.com/LinuxCNC/linuxcnc/blob/2.8/src/emc/rs274ngc/interp_inverse.cc#L124

-- 
Dewey Garrett



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Re: [Emc-users] G93 minimum value/behaviour

[andy pugh]

On Mon, 14 Sep 2020 at 16:27, Robert Ellenberg  wrote:

> I think a smarter approach would be to check if the effective feed rate is
> too small (like below what a machine can actually execute)

Is there any physical limit to how slowly an axis can move? We nearly
all own a device that moves less than 1" per hour...

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] ot: welders

[grumpy--- via Emc-users]

On Mon, 14 Sep 2020, Mark Johnsen wrote:


I'd be interested in the list as well.  Would be nice to know what kind of
mat'l you want to weld and what type of welder you're looking for.

i'm retired
just look'n to weld steel at home
a stick welder
for about 20 years i was attached at the hip to a lincoln stovepipe
i've tried a couple of the cheap inverters and they are better than noth'n
just barely
i know have'n a motor-generator unit at home is out of the question
but surely something comes close




I recall we got an inexpensive Miller welder for the machine shop about 10
years ago and one of the guru-techs (ie years of fab experience) used it
and thought it was darn right excellent when compared to a more expensive
MIller (probably syncrowave).  At least when you looked at the price.
Others raved about it as well...  (I had no clue... haha).

I think it was
https://www.millerwelds.com/equipment/welders/tig-gtaw/diversion-180-tig-welder-m00337,
however, the unit I recall looked more like the $5k unit on the miller
website w/ the exception we definitely paid about 3K for the version we got
(and didn't get a 5k welder for 3k).  We probably paid about list price for
it...

That being said, there are other brands for much less $$.  I think I read
that everlast was a decent 'less expensive' welder and on amazon they have
several models.  However, I have not used one and you'd have to hear from
someone who knows better than I do.

Mark

On Mon, Sep 14, 2020 at 7:10 AM grumpy--- via Emc-users <
emc-users@lists.sourceforge.net> wrote:


this list is home to a bunch of very sharp folks
and i don't intend to drag y'all too far off course
i am look'n for a welder
does anyone know of a good mail'n list for non-pro welders


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Re: [Emc-users] ot: welders

[Mark Johnsen]

I'd be interested in the list as well.  Would be nice to know what kind of
mat'l you want to weld and what type of welder you're looking for.

I recall we got an inexpensive Miller welder for the machine shop about 10
years ago and one of the guru-techs (ie years of fab experience) used it
and thought it was darn right excellent when compared to a more expensive
MIller (probably syncrowave).  At least when you looked at the price.
Others raved about it as well...  (I had no clue... haha).

I think it was
https://www.millerwelds.com/equipment/welders/tig-gtaw/diversion-180-tig-welder-m00337,
however, the unit I recall looked more like the $5k unit on the miller
website w/ the exception we definitely paid about 3K for the version we got
(and didn't get a 5k welder for 3k).  We probably paid about list price for
it...

That being said, there are other brands for much less $$.  I think I read
that everlast was a decent 'less expensive' welder and on amazon they have
several models.  However, I have not used one and you'd have to hear from
someone who knows better than I do.

Mark

On Mon, Sep 14, 2020 at 7:10 AM grumpy--- via Emc-users <
emc-users@lists.sourceforge.net> wrote:

> this list is home to a bunch of very sharp folks
> and i don't intend to drag y'all too far off course
> i am look'n for a welder
> does anyone know of a good mail'n list for non-pro welders
>
>
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Re: [Emc-users] G93 minimum value/behaviour

[Robert Ellenberg]

There is a quirk with G93 in one specific case that causes trouble. G93 for
reasons unknown enforces a minimum feedrate of 0.1 units / min:

https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_inverse.cc#L65

...
  length = find_arc_length(x1, y1, z1, cx, cy, turn, x2, y2, z2);
  rate = std::max(0.1, (length * block->f_number));
  enqueue_SET_FEED_RATE(rate);
...

This causes trouble because of how LinuxCNC understands feed rates / motion
distances
.
As long as there is any XYZ motion longer than 1e-7 inches, the length of
the motion is computed solely in terms of XYZ distance, and the ABC axes
move at whatever feed is necessary to be in phase with the XYZ motion.

An extreme example:
N1 G20 G0 X0 Y0 Z0 A0
N2 G93 G1 Z-0.01 A[360*5] F1.0 (1 minute for 5 revolutions)

The "length" in move N2 is 0.01 in. Based on the code above, the natural
feed rate for this would be 0.01, but it's forced to be 0.1, or 10x higher
than you'd expect.

I think a smarter approach would be to check if the effective feed rate is
too small (like below what a machine can actually execute) and throw an
error, rather than silently "fixing" it like this.

-Rob

On Mon, Sep 14, 2020 at 10:44 AM Gene Heskett  wrote:

> On Monday 14 September 2020 10:24:49 Scott Harwell via Emc-users wrote:
>
> >  Andy
> > I agree this seems more trouble than needed, but if you can get
> > working G code for an example it should help in fixing the post.
> >
> > Could it be a problem with axis wrap (going past 359.999) in the
> > formatting? I understand you can program multiple turns on the rotary
> > axis but what dose the next move expect for an endpoint after rollover
> > on actual position? From A0 to A720 is two rotations but is the next
> > line for two rotations A 720 or A1440?
> >
> > Scott
>
> In my setups, others could be different, but angles are absolute using
> home as a zero reference.
>
> Homeing on a rotary however is to the home switch, you can run it 45000
> degrees as in this thread, but it will rehome to 0, or whatever offset
> from the switch is programmed, in under a turn.
>
> To answer the question, if you have run it to 720 previously, then a cmd
> to go 1440, will turn it two more turns and conversely a cmd to
> goto -1440 will turn it 6 turns in the opposite direction.
> >
> > On Monday, September 14, 2020, 4:30:45 AM CDT, andy pugh
> >  wrote:
> >
> >  On Mon, 14 Sep 2020 at 04:38, Scott Harwell via Emc-users
> >
> >  wrote:
> > >  I found this it might help.
> > > Scott
> > > Rapid Rotary
> >
> > Along the same lines, there is a filter file here that automatically
> > converts XY UV G-code to G93 based on which end is bigger.
> > https://forum.linuxcnc.org/38-general-linuxcnc-questions/35141-a-head-
> >scratcher-for-me?start=10#120524
> >
> > The only reason I mention this is that it runs automatically as the
> > G-code file is opened, rather than being a separate application.
> > (And, to be fair, this isn't an option for RapidRotary as it needs to
> > be able to query the working radius)
>
>
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> If we desire respect for the law, we must first make the law respectable.
>  - Louis D. Brandeis
> Genes Web page 
>
>
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>

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Re: [Emc-users] changing from 5i20 to 6i24

[Peter C. Wallace]

On Mon, 14 Sep 2020, Ed wrote:


Date: Mon, 14 Sep 2020 09:08:01 -0500
From: Ed 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "Enhanced Machine Controller (EMC)" 
Subject: [Emc-users] changing from 5i20 to 6i24

Well, my ancient computer that drives a lathe died and I no longer have any 
machines with the PCI interface that the 5i20 needs.


What would be the easiest way to switch to a 6i24-16? I bought one not 
realizing that it is not in the PNCCONF setup wizard and I am lost without 
it. I will have a few questions after as it has a tool changer and its 
associated files.



Thanks, Ed.




The easiest thing would be to just use your existing hal and ini files
just changing all instances of "5i20" with "5i24" in the hal or ini files
(that's not a typo, the 6I24 normally uses 5I24 firmware so identifies as a 
5I24)


The other thing you would need to do is flash the 6I24 card with appropriate
firmware. Unlike the 5I20 that has firmware loaded at linuxCNC startup, the
6I24 loads its firmware from on board memory at power-on. Updating the
flash memory is done with the mesaflash utility. What firmware was the 5I20 
using?




Peter Wallace
Mesa Electronics



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Re: [Emc-users] G93 minimum value/behaviour

[Gene Heskett]

On Monday 14 September 2020 10:24:49 Scott Harwell via Emc-users wrote:

>  Andy
> I agree this seems more trouble than needed, but if you can get
> working G code for an example it should help in fixing the post.
>
> Could it be a problem with axis wrap (going past 359.999) in the
> formatting? I understand you can program multiple turns on the rotary
> axis but what dose the next move expect for an endpoint after rollover
> on actual position? From A0 to A720 is two rotations but is the next
> line for two rotations A 720 or A1440?
>
> Scott

In my setups, others could be different, but angles are absolute using 
home as a zero reference.

Homeing on a rotary however is to the home switch, you can run it 45000 
degrees as in this thread, but it will rehome to 0, or whatever offset 
from the switch is programmed, in under a turn.

To answer the question, if you have run it to 720 previously, then a cmd 
to go 1440, will turn it two more turns and conversely a cmd to 
goto -1440 will turn it 6 turns in the opposite direction.
>
> On Monday, September 14, 2020, 4:30:45 AM CDT, andy pugh
>  wrote:
>
>  On Mon, 14 Sep 2020 at 04:38, Scott Harwell via Emc-users
>
>  wrote:
> >  I found this it might help.
> > Scott
> > Rapid Rotary
>
> Along the same lines, there is a filter file here that automatically
> converts XY UV G-code to G93 based on which end is bigger.
> https://forum.linuxcnc.org/38-general-linuxcnc-questions/35141-a-head-
>scratcher-for-me?start=10#120524
>
> The only reason I mention this is that it runs automatically as the
> G-code file is opened, rather than being a separate application.
> (And, to be fair, this isn't an option for RapidRotary as it needs to
> be able to query the working radius)


Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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Re: [Emc-users] changing from 5i20 to 6i24

[Todd Zuercher]

If space isn't' an issue, maybe you could use a PCI-e to PCI adapter with your 
5i20.

Otherwise, first you'd need to flash the appropriate firmware to the 5i64 using 
Mesa Flash.  Unlike the 5i20, the 5i64 does not load the firmware at run time, 
it is saved in its flash memory like Mesa's other newer FPGA cards.  Then I 
would think you should only need to find and replace 5i20 with 5i64 in your 
config files with a text editor.

(This would only be my educated guess though.  Since I have no direct 
experience with either of those cards.  I'm sure those more knowledgeable than 
I will correct my assumptions.)

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Ed  
Sent: Monday, September 14, 2020 10:08 AM
To: Enhanced Machine Controller (EMC) 
Subject: [Emc-users] changing from 5i20 to 6i24

[EXTERNAL EMAIL] Be sure links are safe.

Well, my ancient computer that drives a lathe died and I no longer have any 
machines with the PCI interface that the 5i20 needs.

What would be the easiest way to switch to a 6i24-16? I bought one not 
realizing that it is not in the PNCCONF setup wizard and I am lost without it. 
I will have a few questions after as it has a tool changer and its associated 
files.


Thanks, Ed.




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Re: [Emc-users] G93 minimum value/behaviour

[Scott Harwell via Emc-users]

 Andy
I agree this seems more trouble than needed, but if you can get working G code 
for an example it should help in fixing the post. 

Could it be a problem with axis wrap (going past 359.999) in the formatting? I 
understand you can program multiple turns on the rotary axis but what dose the 
next move expect for an endpoint after rollover on actual position?
From A0 to A720 is two rotations but is the next line for two rotations A 720 
or A1440?

Scott

On Monday, September 14, 2020, 4:30:45 AM CDT, andy pugh 
 wrote:  
 
 On Mon, 14 Sep 2020 at 04:38, Scott Harwell via Emc-users
 wrote:
>
>  I found this it might help.
> Scott
> Rapid Rotary

Along the same lines, there is a filter file here that automatically
converts XY UV G-code to G93 based on which end is bigger.
https://forum.linuxcnc.org/38-general-linuxcnc-questions/35141-a-head-scratcher-for-me?start=10#120524

The only reason I mention this is that it runs automatically as the
G-code file is opened, rather than being a separate application.
(And, to be fair, this isn't an option for RapidRotary as it needs to
be able to query the working radius)

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912  
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Re: [Emc-users] update on the harmonic drive.

[Gene Heskett]

Hi all;

Allready sent this to Hubert, thought I'd add my comments to the archive.

I have used about half that roll of PETG, but have not succeeded in 
getting a fit that runs with minimal backlash, and will last overnight 
running at about 200 rpm input.  Its breaking the spline off the upper 
edge of the cup if I make the fit tighter than about a degree of 
backlash.

So ATM I have black PLA back on the printer, going to make 3 internal 
splines as close to 100mm in outer diameter so it fits the housing well.

Then I'll make the last of 3 body caps out of PETG for its higher temp 
tolerance as these motors run hot, but if you are watching the list, 
that problem is fixable by using a near module, setting in1 to 0.0, 
and feeding the PID's vel-cmd to in2, the output to a not to invert it 
so I can wire it to the two current pins of the driver chip, effectively 
sending 2.75 amps to the motor when its moving, but throttling it to 20% 
of that when its not moving.  Making a 2M542 driver out of a $8 (ebay) 
TB6560 driver, mainly because I have 4 of the things I took out of a 
6040 gantry mill I bought myself for a birthday present 2 years ago.

Then I'll switch to TPU after I run the flexgear thru cura again and add 
2 more vertical walls and one or 2 more bottom layers to improve its 
torsional stiffness. That will add a load dependent error of at least 
the backlash, because of the rubbery quality of the TPU, on top of the 
backlash, however there's at least that level of non-linearity in the 
output anyway due to motor shaft centering error in the printed pieces, 
you can actually see the speed variations as it turns slowly.  
Definitely not a candidate to run a telescope with even using a guide 
star.

Last, play with the bearing carriers size to fit the new flexgear, and 
make them out of PETG because of the heat that telegraphs up the motor 
shaft.

Thats the plan.  Its been educational, but the repeated failures are 
getting old. I had zero failures with the TPU but I did have to put the 
whole Micro-Swiss kit at another $100 on the printer before I could use 
TPU, it moves the ejector drive from the left post to the top of the hot 
end, and which led to hot end freezeups from liquified plastic running 
back up into the heat sink and solidifying, until I put the OEM hot end 
back on the new carriage. Different internal design but its not "hi 
flow".  PETG needs at least 250C nozzle temps to get near a usable flow.

So thats the news from West Virginia and great great grandpas workshop.

Stay safe and well everybody.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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[Emc-users] changing from 5i20 to 6i24

[Ed]

Well, my ancient computer that drives a lathe died and I no longer have 
any machines with the PCI interface that the 5i20 needs.


What would be the easiest way to switch to a 6i24-16? I bought one not 
realizing that it is not in the PNCCONF setup wizard and I am lost 
without it. I will have a few questions after as it has a tool changer 
and its associated files.



Thanks, Ed.




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[Emc-users] ot: welders

[grumpy--- via Emc-users]

this list is home to a bunch of very sharp folks
and i don't intend to drag y'all too far off course
i am look'n for a welder
does anyone know of a good mail'n list for non-pro welders


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Re: [Emc-users] OT: Cheap chinese servo motors

[andrew beck]

I haven't used them yet.  They are just planatary reducers.

But might be OK

On Mon, Sep 14, 2020, 9:03 AM dave engvall  wrote:

> Has anyone scrolled down the iink to check the reducers?
> I'm not a stepper person but they might make a good start at a 4th axis.
> :-)
>
> Dave
>
> On 9/11/20 11:51 PM, andrew beck wrote:
> > Leonardo.  I'll pm you my supplier I use us cheaper and I have been
> testing
> > there quality for 2 years on several machines
> >
> > Regards
> >
> > Andrew
> >
> > On Sat, Sep 12, 2020, 7:24 AM Leonardo Marsaglia 
> > wrote:
> >
> >> Helo to all,
> >>
> >> I found these on Aliexpress:
> >>
> >>
> >>
> https://www.aliexpress.com/item/1005001376368510.html?spm=2114.12010612.8148356.2.5d5325f21j0XN8
> >>
> >> What do you think? The price is more than good. The seller has good
> >> feedback on all the listings but sadly, no enough sales to be sure.
> >>
> >> I'm tempted to buy these to drive the router but I don't really know if
> >> they will be reliable enough.
> >>
> >> Thanks as always.
> >>
> >> Leonardo
> >>
> >> ___
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> >> https://lists.sourceforge.net/lists/listinfo/emc-users
> >>
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> > https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
>
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Re: [Emc-users] G93 minimum value/behaviour

[andy pugh]

On Mon, 14 Sep 2020 at 04:38, Scott Harwell via Emc-users
 wrote:
>
>  I found this it might help.
> Scott
> Rapid Rotary

Along the same lines, there is a filter file here that automatically
converts XY UV G-code to G93 based on which end is bigger.
https://forum.linuxcnc.org/38-general-linuxcnc-questions/35141-a-head-scratcher-for-me?start=10#120524

The only reason I mention this is that it runs automatically as the
G-code file is opened, rather than being a separate application.
(And, to be fair, this isn't an option for RapidRotary as it needs to
be able to query the working radius)

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1912


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Re: [Emc-users] I think I have an unsolvable problem

[Gene Heskett]

On Sunday 13 September 2020 21:28:48 Gregg Eshelman via Emc-users wrote:

> There are companies that regrind worn ball screws then stuff them with
> oversized balls, at much lower cost than a whole new ballscrew. ISTR
> reading some claims of making a rolled screw as precise as a new
> ground one since they're precision grinding the old rolled surface.
> Whether or not it's cost effective to have a screw rebuilt would
> depend on how easy or not it is to install a new one. If your machine
> has something crazy custom then a regrind could be best.

I think one might say its custom.  No end machining, so I cut to length, 
then bored a piece of A2 for a slip fit, put a slow tapered 50 tpi 
thread on the OD by cheating on g76, made nuts to fit the taper, then 
edm'd 4 slots .030 wide to the bottom of the hole, wet the screw with 
green loctite, pushed it into the bore and brought the nuts up to about 
1/8 turn from broke, so effectively the rear of the shaft the motor 
turns becomes the screw.  There's also a couple torrington cartridges 
around the shaft and miniature roller thrust washers countersunk into 
both front and rear faces of the original crank boss, without enough 
clearance to ever allow swarf to penetrate.  The top and bottom of the 
channel the screw occupy's has been sealed up, so the screw itself is 
running in a sealed clean environment. My 25mm Z screw is fitted with a 
covering bellows on both sides of the carriage ball nut so it has a 
clean environment too.  It has factory wiper felts in the nut that I 
grease about annually, and this custom x screw has wipers on both ends 
of the nut that I made froman old felt hat. The anchoring bolt for the 
nut cage can be removed and a cc or so on vactra 68 poured into the nut 
cage, which is sealed on the bottom. I intended it to outlast me.

> Regrinding 
> would also be best if the screw is worn a lot more in one area.
> Oversized balls that take up nearly all the lash in the less worn
> areas will still leave the most worn spot loose.
>
This is true, but there wasn't much mileage on these screws so the thou 
oversize worked well.

Have you a URL for one of these re-grinders?

> On Sunday, September 13, 2020, 3:34:26 PM MDT, Gene Heskett
>  wrote:
>
>  On Sunday 13 September 2020 15:18:57 andy pugh wrote:
> > On Sun, 13 Sep 2020 at 17:29, Gene Heskett 
>
> wrote:
> > > Worse yet, if that screw does get damaged, I have no clue where to
> > > source another like it. That small has never shown up on fleabay.
> >
> > https://www.automationshop.co.uk/mec
>
> No, they don't. 1 16mm, the smaller ones are all out of stock from
> this side of the pond. These nuts have flanges that would preclude
> using them in the available space.  The ones I am using aren't
> threaded or flanged, so I had to make cages to fit them.  They are
> 19mm in diameter plus return tubes. Looks like warmed over hell, but
> the backlash is about a thou.
>
> > Or, second-hand from Korea: https://www.ebay.com/itm/193192165382
>
> At least they are honest, all worn out, the precise is used up.
> These were worn some but I found a bag of oversized balls ,0635 in
> diameter, .001" oversized, and re-stuffing them was a bit tedious but
> I did get it done. Took nearly all the backlash out of them.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


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