Hi Tomp,
I understand the process and the step response. One thing in the mix that we
haven't discussed, and I really was hoping Jon Elson would chime in again, is
exactly how much impact the servo drive has on all this.
The application of DC voltage to a motor and then measuring up to spee
Looking at schematics or equations at
https://en.wikipedia.org/wiki/Armature_Controlled_DC_Motor for a DC motor it
could be seen armature voltage may be changed instantly while current take some
time to change because of inductance in rotor marked "L rotor". To change motor
speed require torque
On Wed, 22 Jul 2020 at 21:54, andrew beck wrote:
>
> I have been noticing a bit of jumping around
> when doing parallel finishing 3d passed on it at high speed.
I wonder what effect could be had by rate-limiting the PID output to
the motors?
You would expect it to increase following-error (but
On Thu, 23 Jul 2020 at 05:55, John Dammeyer wrote:
>
> I've asked a retired physics professor friend for some enlightenment.
I have a PhD in Physics, but seem to be being ignored.
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical
> -Original Message-
> From: andy pugh [mailto:bodge...@gmail.com]
> Sent: July-23-20 1:03 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Calculating table acceleration. Was: Need help with
> Bostomatic BD18-2 to linuxcnc
>
> On Thu, 23 Jul 2020 at 05:55, John Dam
On Thursday 23 July 2020 01:57:46 John Dammeyer wrote:
> Hi Chris,
>
> > -Original Message-
> > From: Chris Albertson [mailto:albertson.ch...@gmail.com]
> >
> > Why on Earth do people still use US units? OK if your final result
> > must be expressed that way, but do the math in metric th
A G is a G is a G. As a unit of acceleration, it doesn't matter what
vector that unit of acceleration takes. I flew fighters for the USAF
for years. I've pulled G's in just about any direction possible.
On 7/23/20 12:52 AM, John Dammeyer wrote:
I've asked a retired physics professor friend
Great work! Seems like a nice way to maek a gear if you’re patient.
> On Jul 22, 2020, at 10:39 PM, andrew beck wrote:
>
> Hey everyone just a quick video here. Might interest people.
>
> https://youtu.be/3u1bZxd-KCk
>
> Regards
>
> Andrew
>
> __
On Thu, 23 Jul 2020 at 09:22, John Dammeyer wrote:
> Not ignoring you at all. Just waiting for an idea for the math that leads to
> calculating MAX_ACCELERATION in the ini file given the parameters I've
> mentioned before.
I think that the problem is treating the motor as an ideal torque
sour
On Thu, 23 Jul 2020 at 11:09, andy pugh wrote:
> I += L * (Vs - Vb) dt
Oops!
V = L di/dt
di = (V / L) dt
So that should be
I += (Vs-Vb)/L dt
--
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics.
I should also note I made an error in my revolutions calculation. It should be
RPM / 2 / 60 sec * deceleration time = revolutions to stop, assuming linear
deceleration. That’s probably the default for most drives. For 560 RPM, that
comes out to 2.8 revolutions. So my observations at 2.9 revo
On Thu, 23 Jul 2020 at 03:41, andrew beck wrote:
> https://youtu.be/3u1bZxd-KCk
With a 4th axis (which I realise you don't have) you would be able to
generate a tooth form using the flank of the cutter in just the same
way as you can with a shaper.
(Ideally you would use a conical tool bit groun
That’s a fascinating idea. I was pondering CNC’ing my shaper, but a fourth
axis would be much easier. Even if you don’t have a conical tool bit. Albeit
the surface finish might be a little rougher, it should work well enough for
most applications.
> On Jul 23, 2020, at 6:20 AM, andy pugh w
On Thu, 23 Jul 2020 at 11:24, Matthew Herd wrote:
> Who is in charge of the integrator’s manual? I’d like to investigate writing
> some additional sections.=
We all are. :-)
The "Integrator manual" may not be the manual you need to change, but
is made of these files.
https://github.com/LinuxC
On Thursday 23 July 2020 06:33:08 Matthew Herd wrote:
> That’s a fascinating idea. I was pondering CNC’ing my shaper, but a
> fourth axis would be much easier. Even if you don’t have a conical
> tool bit. Albeit the surface finish might be a little rougher, it
> should work well enough for most
> On Thu, 23 Jul 2020 at 05:55, John Dammeyer wrote:
> >
> > I've asked a retired physics professor friend for some enlightenment.
>
> I have a PhD in Physics, but seem to be being ignored.
Maybe I missed what you said?
___
Emc-users mailing list
Emc
> On Thu, 23 Jul 2020 at 09:22, John Dammeyer wrote:
>
> > Not ignoring you at all. Just waiting for an idea for the math that leads
> > to calculating MAX_ACCELERATION in the ini file given the parameters I've
> > mentioned before.
>
> I think that the problem is treating the motor as an ide
> > I have been noticing a bit of jumping around
> > when doing parallel finishing 3d passed on it at high speed.
>
> I wonder what effect could be had by rate-limiting the PID output to
> the motors?
Integrator should ideally have anti-windup. Know about and how it should be
implemented? Othe
On Thu, 23 Jul 2020 at 12:27, Gene Heskett wrote:
> I have spent considerable
> time looking for shaped tools/mills for such gear cutting and either
> didn't recognize it from the description or came up empty.
https://www.amazon.com/s?k=involute+gear+cutter
https://www.ebay.com/sch/i.html?_from=
On Thu, 23 Jul 2020 at 12:47, Nicklas SB Karlsson
wrote:
> > I wonder what effect could be had by rate-limiting the PID output to
> > the motors?
>
> Integrator should ideally have anti-windup.
Anti-windup is a little different.
I was actually thinking about experimenting with a limit3 HAL
comp
чт, 23 лип. 2020 о 14:58 andy pugh пише:
> I was actually thinking about experimenting with a limit3 HAL
> component between the PID and the PWM.
>
KFLOP has lowpass filter
http://dynomotion.com/Help/KMotionCNC/TrajectoryPlanner.htm
WBR,
Andrew
___
On Thursday 23 July 2020 07:53:45 andy pugh wrote:
> On Thu, 23 Jul 2020 at 12:47, Nicklas SB Karlsson
>
> wrote:
> > > I wonder what effect could be had by rate-limiting the PID output
> > > to the motors?
> >
> > Integrator should ideally have anti-windup.
>
> Anti-windup is a little different.
It's really not a big deal. Engineering and science is full of math
operations that you have to jump to all the time. If it is too difficult
find someone else that is not a complainer to help you.
On 7/23/20 12:34 AM, Chris Albertson wrote:
Why on Earth do people still use US units? OK if
On 7/23/20 7:53 AM, Bari wrote:
It's really not a big deal. Engineering and science is full of math
operations that you have to jump to all the time. If it is too
difficult find someone else that is not a complainer to help you.
On 7/23/20 12:34 AM, Chris Albertson wrote:
Why on Earth do p
On Thu, Jul 23, 2020 at 11:35 AM dave engvall wrote:
>
>
> On 7/23/20 7:53 AM, Bari wrote:
> > It's really not a big deal. Engineering and science is full of math
> > operations that you have to jump to all the time. If it is too
> > difficult find someone else that is not a complainer to help yo
On 07/22/2020 11:52 PM, John Dammeyer wrote:
But does the accel value in F=ma have to be gravity? And if not, what then?
No! G and weight in Lbs are convenient units because we
live on earth. They are useless anywhere else.
But, they are familiar to anyone who lives here.
mass is a co
On 07/23/2020 12:00 AM, andrew beck wrote:
Yes I'm not worried about servo following error spikes. But I'm shaking my
whole machine to death. As the acceleration is instantly on. In contrast
a friend's okuma can go at 40m/min without shaking. Which is amazing to
watch. They are both similar
A link to a video for this thing showed up in my facecrap feed. It
looks like a UC-100 only for LinuxCNC 2.9. They are demoing on a Pi
4. Has anyone got any experience with the Linumeric-LPT v1? Price
and ordering are not shown on the site, you are directed to email
them.
Product Link - http:/
On 07/23/2020 02:00 AM, John Dammeyer wrote:
Hi Tomp,
I understand the process and the step response. One thing in the mix that we
haven't discussed, and I really was hoping Jon Elson would chime in again, is
exactly how much impact the servo drive has on all this.
Well, both the motor and t
On 07/23/2020 05:09 AM, andy pugh wrote:
On Thu, 23 Jul 2020 at 09:22, John Dammeyer wrote:
Not ignoring you at all. Just waiting for an idea for the math that leads to
calculating MAX_ACCELERATION in the ini file given the parameters I've
mentioned before.
I think that the problem is trea
On 07/23/2020 05:21 AM, Matthew Herd wrote:
I should also note I made an error in my revolutions calculation. It should be
RPM / 2 / 60 sec * deceleration time = revolutions to stop, assuming linear
deceleration. That’s probably the default for most drives. For 560 RPM, that
comes out to 2.
Agreed, it generally isn't much different working in US vs metric, you just
have to make sure ALL of your units always jive. (and I don't think you have to
use slugs) You can still have the same problems in metric, but there those
mistakes often only results in a decimal point miss placement, b
This might have been mentioned on the MACH CNC group but the reality is that if
you want LinuxCNC and two parallel ports the MESA 7i92 is less expensive and
not tied to potential speed issues via USB. For example WIN-10 won't run the
USB based Smooth Stepper but will run the Ethernet Smooth S
> -Original Message-
> From: Jon Elson [mailto:el...@pico-systems.com]
> Sent: July-23-20 9:00 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Calculating table acceleration. Was: Need help with
> Bostomatic BD18-2 to linuxcnc
>
> On 07/23/2020 05:09 AM, andy pugh
I am going to get one and report back
On 2020/07/23 17:41, Dave Matthews wrote:
A link to a video for this thing showed up in my facecrap feed. It
looks like a UC-100 only for LinuxCNC 2.9. They are demoing on a Pi
4. Has anyone got any experience with the Linumeric-LPT v1? Price
and orderin
> On Thu, 23 Jul 2020 at 12:47, Nicklas SB Karlsson
> wrote:
>
> > > I wonder what effect could be had by rate-limiting the PID output to
> > > the motors?
> >
> > Integrator should ideally have anti-windup.
>
> Anti-windup is a little different.
>
> I was actually thinking about experimenting
> On Thursday 23 July 2020 07:53:45 andy pugh wrote:
>
> > On Thu, 23 Jul 2020 at 12:47, Nicklas SB Karlsson
> >
> > wrote:
> > > > I wonder what effect could be had by rate-limiting the PID output
> > > > to the motors?
> > >
> > > Integrator should ideally have anti-windup.
> >
> > Anti-windup
The biggest plus I see is that if it is easy to set up it might be a
good way to go, especially at $90 delivered. I am not a big fan of
USB but it does seem to work fine for the Mach 3 crowd. The biggest
negative I see for the Mesa products is that they are very difficult
to get set up for most p
Is the 7i92 less expensive? Do we even know the price of this USB->DB25
device?
What is really needed is for someone to write firmware for the common
STM32F103 "Blue Pill". These have the hardware to do things like step gen
and quadrature decode at MHz speeds and talk to the PC over SPI I2C or
Does it even work with LinuxCNC?
Sent from John's iPhone 4S
On 2020-07-23, at 11:07 AM, Dave Matthews wrote:
> The biggest plus I see is that if it is easy to set up it might be a
> good way to go, especially at $90 delivered. I am not a big fan of
> USB but it does seem to work fine for the M
That is what the video is. It is being used as an interface from a
Raspberry Pi 4 running LinuxCNC. From the info on the website it is
LinuxCNC only.
Dave
On Thu, Jul 23, 2020 at 2:17 PM John wrote:
>
> Does it even work with LinuxCNC?
>
> Sent from John's iPhone 4S
>
> On 2020-07-23, at 11:07
On Thu, Jul 23, 2020 at 2:18 PM Chris Albertson
wrote:
>
> Is the 7i92 less expensive? Do we even know the price of this USB->DB25
> device?
>
$65 + $25 shipping to the US. Given the shipping cost of the 7i92
plus the cost of the cable needed it is less expensive.
> Just perhaps this is what t
I think the answer to your question is, you need to stay with a unit of g
because that is what you started out with.
Imperial units for torque, oz-in, lb-in, lb-ft, are defined by the force of
gravity on a mass of one lb (or oz).
Si unit of torque is Newton-meters. No need to involve g when usin
On Thu, 23 Jul 2020 at 18:05, John Dammeyer wrote:
> In my case the Motor inertia is 3.4kg/cm^2.
> However, I suspect that the energy required to spin the pulleys and lead
> screw (1000 RPM for the lead screw with 3:1 on the motor) is a small part of
> moving a 220 lb (100kg) table with a moto
On Thu, 23 Jul 2020 at 18:30, Nicklas SB Karlsson
wrote:
> Limit3 function is what trajector planner must follow if acceleration is
> allowed to change instantly, if jerk could be changed instantly it had to
> follw a limit4 function
...
> In doubt Limit3 function is useful in between PID and P
Greetings all;
Slow, makes watching grass grow exciting... 3h:40m into making the
housing cup, its claiming 6% done. And still doing infill for the end
wall stuck on the bed.
Someone said that it will need grease and mentioned the silicon stuff
used in power tool gear boxes. But one of the fe
On Thursday 23 July 2020 12:21:15 John Dammeyer wrote:
> This might have been mentioned on the MACH CNC group but the reality
> is that if you want LinuxCNC and two parallel ports the MESA 7i92 is
> less expensive and not tied to potential speed issues via USB. For
> example WIN-10 won't run the
On Thursday 23 July 2020 13:34:48 Nicklas SB Karlsson wrote:
> > On Thursday 23 July 2020 07:53:45 andy pugh wrote:
> > > On Thu, 23 Jul 2020 at 12:47, Nicklas SB Karlsson
> > >
> > > wrote:
> > > > > I wonder what effect could be had by rate-limiting the PID
> > > > > output to the motors?
> > >
On Thu, 23 Jul 2020 at 17:06, Jon Elson wrote:
> > Who is in charge of the integrator’s manual? I’d like to investigate
> > writing some additional sections.
> >
> You can submit suggested changes to John Thornton, or get
> commit access yourself.
Fir docs you can edit the asccidoc file live o
Teflon or PTFE
Some have reported using Lithium grease for over a year without issues.
The water content might be an issue over time but you're probably not
looking at years of service on the gears anyway.
https://www.machinedesign.com/motors-drives/article/21831576/engineering-essentials-lub
> -Original Message-
> From: Dave Matthews [mailto:n36...@gmail.com]
> Sent: July-23-20 11:24 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Machmaker USB -> Parallel
>
> On Thu, Jul 23, 2020 at 2:18 PM Chris Albertson
> wrote:
> >
> > Is the 7i92 less expensive?
I would very much like to hear what the experts at Mobile say, if you can
get an answer from them.
But what I do is save fail and redesigned printed parts so I can do
experiments on them like testing of Epoxy or CA glue is best or just put
them in a vice and bend 'till they break. I've never don
> Greetings all;
>
> Slow, makes watching grass grow exciting... 3h:40m into making the
> housing cup, its claiming 6% done. And still doing infill for the end
> wall stuck on the bed.
>
> Someone said that it will need grease and mentioned the silicon stuff
> used in power tool gear boxes. B
On 7/23/20 10:41 AM, Dave Matthews wrote:
A link to a video for this thing showed up in my facecrap feed. It
looks like a UC-100 only for LinuxCNC 2.9. They are demoing on a Pi
4. Has anyone got any experience with the Linumeric-LPT v1? Price
and ordering are not shown on the site, you are d
On 7/23/20 2:23 PM, John Dammeyer wrote:
And it's still USB. Can it handle a 2500 line quadrature encoder? The
control is the small part of the overall CNC conversion. I found that buying
the CNC Cape for the BeagleBone which all around seemed like the lowest entry
cost ultimately wasn't
> On 07/23/2020 05:09 AM, andy pugh wrote:
> > On Thu, 23 Jul 2020 at 09:22, John Dammeyer wrote:
> >
> >> Not ignoring you at all. Just waiting for an idea for the math that leads
> >> to calculating MAX_ACCELERATION in the ini file given the parameters I've
> >> mentioned before.
> > I think
On Thu, 23 Jul 2020, Bari wrote:
Date: Thu, 23 Jul 2020 14:29:55 -0500
From: Bari
Reply-To: "Enhanced Machine Controller (EMC)"
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] Machmaker USB -> Parallel
On 7/23/20 10:41 AM, Dave Matthews wrote:
A link to a video for this thi
> On Thursday 23 July 2020 13:34:48 Nicklas SB Karlsson wrote:
>
> > > On Thursday 23 July 2020 07:53:45 andy pugh wrote:
> > > > On Thu, 23 Jul 2020 at 12:47, Nicklas SB Karlsson
> > > >
> > > > wrote:
> > > > > > I wonder what effect could be had by rate-limiting the PID
> > > > > > output to t
Gene I can get. Custom shaped endmills made in china easy as which is what
I will probably do soon. I might just get some gear tooth shaped endmills
made.. I get custom tools all the time for my tooling company
Regards
Andrew
On Thu, Jul 23, 2020, 11:27 PM Gene Heskett wrote:
> On Thursday 2
Jon machine is going mint. I don't currently have encoders connected back
to the control but I did. The motors are tuned mint. It's just the table
mass at the acceleration jumps a bit when moved.
I might just enable reducing feed rate at corners in fusion360 cam for now
if I can.
I want the ac
On Thursday 23 July 2020 15:26:06 Chris Albertson wrote:
> I would very much like to hear what the experts at Mobile say, if you
> can get an answer from them.
>
> But what I do is save fail and redesigned printed parts so I can do
> experiments on them like testing of Epoxy or CA glue is best or
On Thursday 23 July 2020 16:04:46 andrew beck wrote:
> Gene I can get. Custom shaped endmills made in china easy as which is
> what I will probably do soon. I might just get some gear tooth shaped
> endmills made.. I get custom tools all the time for my tooling
> company Regards
>
> Andrew
>
SW
On Thu, Jul 23, 2020 at 3:25 PM John Dammeyer wrote:
>
>
>
> > > Is the 7i92 less expensive? Do we even know the price of this USB->DB25
> > > device?
> > >
> >
> > $65 + $25 shipping to the US. Given the shipping cost of the 7i92
> > plus the cost of the cable needed it is less expensive.
>
> N
On Thu, Jul 23, 2020 at 3:55 PM Peter C. Wallace wrote:
snip
>
> Looks like it would be fine for a router type applications but not
> mills/lathes
> that need real time feedback for threading, rigid tapping etc. It might
> allow LinuxCNC use without a real time kernel though.
>
My exact applica
On Thu, Jul 23, 2020 at 11:17 AM John wrote:
> Does it even work with LinuxCNC?
>
Their web site says it was specifically designed for LinuxCNC and works
with the stepconf setup app. They claim perfect emulation of the PC
parallel port and that their device can work as the first of second
paral
I hope to be able to do the same but on a MUCH smaller mill. I think you
can even cut helical bevel gears this same way.
One thing, I think this would go faster if you made the first pass with a
larger end mill that could cut faster then do the finish pass using the
tiny end mill.
On Wed, Jul 2
Gene,
Better to just use a standard (replaceable at a reasonable cost) ball mill
and let your CAM software generate the toolpath. No math involved.
If I am making gears I'd not want to have to depend on a steady supply of
hen's teeth. If your part depends on one-off tooling you might never be
a
Hey Gene depends on size. And there are often MOQ or 10 pics. We just try
work it out between us.
Price wise 12mm cutter might be 25 usd.
Small 5mm cutter might cost 8usd.
Off the shelf 6mm endmills for stainless steel. (they are really good
quality. Almost as good as a sandvic one). Cost l
On Thursday 23 July 2020 19:02:47 Chris Albertson wrote:
> Gene,
>
> Better to just use a standard (replaceable at a reasonable cost) ball
> mill and let your CAM software generate the toolpath. No math
> involved.
Yes there is. I know very llittle about CAM so I'd have to write my own.
And its
On Thursday 23 July 2020 19:56:37 andrew beck wrote:
> Hey Gene depends on size. And there are often MOQ or 10 pics. We
> just try work it out between us.
>
> Price wise 12mm cutter might be 25 usd.
>
> Small 5mm cutter might cost 8usd.
>
> Off the shelf 6mm endmills for stainless steel. (they
Could get the same effect as cutting teeth with a multi tooth straight hob. As
the gear is turned, the involute curves are formed as a series of facets. With
a 4th axis under CNC control you can have as many facets as you want. After
milling I'd want to run gears together for a bit with some lap
Gear tooth shaped end mills would be real handy in many situations, especially
where you need two different sized spur gears on one part, and the smaller one
is too close to the larger one for any conventional sort of rotating gear tooth
cutting tool. In olden times those had to be cut with a l
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