CoreXY and handling of axis limits

No, 2,8 is what the master branch will be called when it is released.
2.7.8 is the latest officially released version.

To get the 2.8 / master branch with all the JA updates you need to change the repository settings then update. see:
buildbot.linuxcnc.org

Aha, that would explain a lot! After installing the "real" 2.8 (not 2.7. and a little more tweaking to the config files, I seem to be getting somewhere. Since this version offers to automagically update one's .ini/hal files, I reverted to the ones from before my manual attempt and let it do its thing. The update script defaults to creating joint limits, set equal to the axis limits. This led to the familiar "exceeded xxx limit" errors, but setting the JOINT_0/JOINT_1 (X/Y) limits to (-999999, 999999) seems to have cured it.

With this done, after some brief testing homing appears to still work correctly, AND I can jog X/Y in any legal permutation within the *axis* limits. I'm still getting "joint x following error" halts when running at full speed even after setting fairly lax limits for this, but that's a separate issue and probably down to my not fixing this PC's horrible realtime performance yet.

In case anyone is coming to this thread with the same issue, here are my current config files - maybe a worked example will save someone a bit of time.

Thanks everyone for all of your help!

Drmn4ea wrote: Since this version offers to automagically update one's .ini/hal files, I reverted to the ones from before my manual attempt and let it do its thing. The update script defaults to creating joint limits, set equal to the axis limits.

It has no real choice, there are no other numbers to choose.

I'm still getting "joint x following error" halts when running at full speed even after setting fairly lax limits for this, but that's a separate issue and probably down to my not fixing this PC's horrible realtime performance yet.

Is this a parport/stepper machine? If it is, then the f-error is really reporting that you have asked for more step pulses than it has had the time to create because of the base-period time. So this is indirectly due to latency, but only to the extent that the latency measurement is used to choose a base period.

Hey there. Just to clarify, If I want separate joint and axis configuration in my ini file, I would need to upgrade from 2.7.8 to 2.8, right? Would I then need to change form hm2_5i25 to hm2_pci for my mesa card interface?

Also, would it make sense to keep the RTAI version since that's what I currently have and what works or should I try switching to the new uspace version?

I don't think there has ever been a hm2_5i25 module. hm2_pci will create pins called hm2_5i25... if that is the card fitted.

Dohhh. I was looking a the resulting pins. Sorry about that.


I've upgraded and the only problem I have now is I still need the 4 axes for it to start, even though I have 3 axes and 4 joints. (tetrapod config, not a gantry).

It fails with this error:

./kintest.hal:219: Pin 'joint.3.motor-pos-cmd' does not exist

So it looks like the number of joints is still tied to the number of axes.

When I choose 4 axes, I can jog fine in world mode, but if I try to run a program I get this error:


USRMOT: ERROR: invalid command
Linear move on line 3 would exceed A's positive limit



I've tried including a fake A axis (below) and setting it's limit to a large number, but it still gives me this error.

[AXIS_A]
HOME = 0
MIN_LIMIT = 0
MAX_LIMIT = 99999