binary works - compilation not smoothly???

Hi there,
I have been using linuxcnc for quite a while now. I have a very old Version (2.4.something). I'm using the realtime kernel of an old Linux cnc System. This works really nice.
Now I'm trying to install a 4th axis and wanted to change to the latest linuxcnc (current git master). I also added the rot4thaxiskins from the wiki and adapted the Makefile. Compilation works.

I am using the old ini files (with some apations because ofthe JOINTS Concept and the new kinematics. This works!

But when I am jogging the axis they are not running smoothly…? Did I do thingting wrong during compilation. For me it seems (actually it sounds) that the step-distance is jittering…?

Any hint?

Thanks
Georg

Hello Andy,
thanks for the quick Reply.

Everything is as it was before.this auto-conversion tool did the Settings for the missing joints itself
I will check the config and upload it later.
from my point of view either the pulses are too short, or they are not in constant intervals. I can check this with an oscilloscope in the next days.

Might it be that I'm running without realtime kernel option somehow??


Thanks
Georg

Hello Andy et al,

sorry for the late reply, took me one day to repair the power electronics of one axis I destroyed when I was trying to probe the signals...anyhow...working now again.

I figured out that in good working condition my pulses are 50µs long and 3.3V high. In bad working condition they are only 5µs long but some 800-900µs long Signals are in between them. Seems this causes the jitter.

I added a few attachments for the working and non-working cases. You will find the outputs of the startup and the configurations. I'm using the precompiled binary in case of working and the selfmade compilation in case of non-working.

Thanks a lot for your help. Hope you have an idea
Georg

Hi,
here are the requested outputs.

I didn't mentioned before, that the machine is a stepper machine based on an an L297, but I guess you have seen this from the configs already.


Thanks
Georg

Hi,
thank you very much.
I just tried it out very quickly.It seems to work now.

….now another topic comes up maybe you can help here too:
Using the configuration as shown above "axis" provides me 4 axis only! What do I have to do in order to get the others?

Remember I was trying to use the rot4thaxis kinematics, that means I have three joints for shifting one for rotationg (around x). I would expect at least XYZAVW (V and W will become my new Y and Z axis as YZ will be rotated around A)

Thank you again
Georg