On Thursday 01 July 2021 04:54:32 Les Newell wrote:
> > Re-reading that, linuxcnc will not even start if they don't match
> > exactly.
>
> That's not my experience. What error message do you get?
I can't show it ATM as I haven't yet gone out to reboot those machine yet
this morning, I'm still a
Re-reading that, linuxcnc will not even start if they don't match
exactly.
That's not my experience. What error message do you get?
Les
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
On Wednesday 30 June 2021 21:31:28 Matthew Herd wrote:
> Gene, that’s very odd behavior. My machine isn’t homed (still just
> working on basic tuning) when I’m doing my tests and your behavior
> sounds similar. I wonder if we could determine the reason for this
> difference in behavior.
>
I'd
I'm not familiar with the Pico interface. Basee upon the docs it looks to
be a velocity mode stepgen.
I have a mesa velocity mode Stephen to servo system on my router.
This site was helpful to me getting this set up.
https://gnipsel.com/linuxcnc/tuning/servo.html.
If I recall I had to tune the
On Wednesday 30 June 2021 14:47:57 Les Newell wrote:
> On 30/06/2021 12:52, Gene Heskett wrote:
> > This is good to know Les, thank you. But for those who don't know
> > how to achieve that, a 1 axis example would be a huge help.
>
> In your INI file, there are two places where you can set the
Gene, that’s very odd behavior. My machine isn’t homed (still just working on
basic tuning) when I’m doing my tests and your behavior sounds similar. I
wonder if we could determine the reason for this difference in behavior.
> On Jun 30, 2021, at 9:25 PM, Gene Heskett wrote:
>
> On
On Wednesday 30 June 2021 14:47:57 Les Newell wrote:
> On 30/06/2021 12:52, Gene Heskett wrote:
> > This is good to know Les, thank you. But for those who don't know
> > how to achieve that, a 1 axis example would be a huge help.
>
> In your INI file, there are two places where you can set the
On 30/06/2021 12:52, Gene Heskett wrote:
This is good to know Les, thank you. But for those who don't know how to
achieve that, a 1 axis example would be a huge help.
In your INI file, there are two places where you can set the MIN_LIMIT
and MAX_LIMIT (joint and axis). Just make sure you hit
On Wednesday 30 June 2021 06:30:30 Les Newell wrote:
> On a trivkins machine I don't think it matters much. In coordinated
> mode the lowest speed/acceleration for a given axis will win. In joint
> mode (mainly jogging while unhomed) the joint's speed + acceleration
> are used.
>
> If you are
On a trivkins machine I don't think it matters much. In coordinated mode
the lowest speed/acceleration for a given axis will win. In joint mode
(mainly jogging while unhomed) the joint's speed + acceleration are used.
If you are using soft limits it pays to have to have the axis limits
Ahh, thanks Les. I like the simulated encoder option. The best part is it’s
as easy as flipping a switch. Unfortunately wiring up the drive is a bit more
of an ordeal, although I do have a bunch of steppers and drives as they were
what was replaced. If I get desperate I’ll go that route.
John, Matt isn't using a stepgen. The Pico USC board uses it's own step
generator. Stepgen expects a position command. As far as I can tell from
the USC docs the USC step generator expects a velocity command, hence
the need for a PID loop.
Matt, Do you happen to have a spare stepper and drive
> From: Matthew Herd [mailto:herd.m...@gmail.com]
> Hi John,
>
> I�m just confused, since I�m not clear on how the signal would then be
> communicated if both parameters are set to 0. I did try both
> with zero initially and didn�t observe any movement so I went to P=1. Then I
> saw very slow
EL = 0.01
> HOME_FINAL_VEL = 0.2
> HOME_IGNORE_LIMITS = YES
> HOME_VOLATILE = 1
> #HOME_SEQUENCE = 1
>
>
>> -Original Message-
>> From: Matthew Herd [mailto:herd.m...@gmail.com]
>> Sent: June-29-21 7:32 PM
>> To: Enhanced Machine Controller (EMC)
>
t; Subject: Re: [Emc-users] Advice on Tuning Servo System
>
> I fiddled with the X axis servo drive and tuned the parameters with P=1 and
> jog speed set to 60 IPM. The ferror always returned to
> zero but did so at an exceedingly slow pace. I tuned the drive to the limits
I fiddled with the X axis servo drive and tuned the parameters with P=1 and jog
speed set to 60 IPM. The ferror always returned to zero but did so at an
exceedingly slow pace. I tuned the drive to the limits of stability (or a
little over) and the movement was always so slow you couldn’t
Ok I thought so. I just want to confirm that setting all PID parameters to 0
will allow the velocity commands to pass through. I’d think I’d need P=1 or
something along those lines?
I hope to try this one evening this week if I can get to the shop.
Matthew Herd
herd.m...@gmail.com
Ok I thought so. I just want to confirm that setting all PID parameters to 0
will allow the velocity commands to pass through. I’d think I’d need P=1 or
something along those lines?
I hope to try this one evening this week if I can get to the shop.
Thanks again!
Matthew Herd
I just checked the docs and you are correct. I assumed you were using a
standard stepgen. I didn't realize Pico USC works differently.
Les
On 29/06/2021 13:18, Matthew Herd wrote:
Hi Les,
I’m not sure if that will work with the Pico USC board. If I’m not mistaken
LinuxCNC treats the motors
Hi Les,
I’m not sure if that will work with the Pico USC board. If I’m not mistaken
LinuxCNC treats the motors as servos and the board handles the step generation.
Matt
> On Jun 29, 2021, at 7:42 AM, Les Newell wrote:
>
> Hi Matt,
>
> Use Stepconf to generate an example config. It creates
Hi Matt,
Use Stepconf to generate an example config. It creates a stepper config
without any PID. You can basically cut and paste from that to your hal
files. The drives themselves are doing the PID work in your setup.
Les
On 28/06/2021 22:31, Matthew Herd wrote:
Hi John and Les,
Thank
Sorry meant to say noise comes from the angular contact of the two bevel gears.
The bearings are quiet.
> I swapped in a 750W Bergerda with 3.2:1 and now I get 150 ipm and that's
> scary fast for the knee. And I did upgrade the radial ball
> bearings and bushings for the horizontal shaft to
achine Controller (EMC)
> Subject: Re: [Emc-users] Advice on Tuning Servo System
>
> Hi John and Les,
>
> Thank you for the input. I wasn�t sure how to tune the drives without the
> PID. P=0 & FF1=0 will yield a commanded velocity
> calculated purely on the c
load?
>
> And I agree with Les. Set step/dir, P=0, FF1=0 and first tune the drives
> without LCNC.
>
> John
>
>
>> -Original Message-
>> From: Les Newell [mailto:les.new...@fastmail.co.uk]
>> Sent: June-28-21 8:03 AM
>> To: emc-users@lists.sou
Newell [mailto:les.new...@fastmail.co.uk]
> Sent: June-28-21 8:03 AM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] Advice on Tuning Servo System
>
> Hi Matthew,
>
> That FF1 is probably causing the increasing following error. Again I'd
> strongly recommend
Hi Matthew,
That FF1 is probably causing the increasing following error. Again I'd
strongly recommend using just stepgen rather than a combination of
stepgen and PID. At the moment LCNC and your drives are fighting each other.
The oscillation could be the drive tuning or the loops fighting
Hi Les,
I’m jogging at 60IPM, 120IPM, and 250IPM for testing purposes. Depending on
the PID parameters I was seeing increasing ferror with jog time at all three
speeds. The delay in stopping also seemed to correlate with the ferror.
Tuning eventually brought it down to constant ferror, but
Hi Matthew,
I'd recommend setting this up as a stepper system and ignore the encoder
feedback for now. The feedback loop inside the drive is likely to fight
with the PID loop inside LinuxCNC. The encoders can be used for position
feedback but that's not essential and is just making it harder
Hi Les,
The drives accept step/direction from the USC board to command position, not
velocity. The encoders are pass-through to the USC board and then to LinuxCNC.
Thanks!
Matt
> On Jun 28, 2021, at 9:02 AM, Les Newell wrote:
>
> Hi Matthew,
>
> First of all, how are your drives
Hi Matthew,
First of all, how are your drives configured? Is the step/direction
commanding position to the drives or velocity? If you are using position
(the most common with step/dir) all of your PID tuning should be done in
the drive. Do you have feedback to LCNC from the encoders?
Les
I think I might have been adjusting the wrong velocity & acceleration
parameters … see below for the trajectory planner section of the INI:
I assume that increasing the max linear velocity term will help with at least
some of the issues. And making sure my max linear acceleration is 25%
31 matches
Mail list logo
