0.92 Stuttering/Stalling on Rostock MAX v2

otherguy

I decided to upgrade my Rostock MAX v2 from 0.91 to 0.92.9 for the built-in PT100 support.  I was very careful to make sure the new configuration matched the old one.  I got it to the point where it works well on simple prints, but on more complex ones, specifically slow prints with large curves, it stalls quite a bit leaving blobs all over the place.  In severe cases it will completely lock up requiring a power cycle.  I tried several suggestions from others who posted about stuttering issues but wasn't able to get any improvement.

I went ahead and back ported the PT100 code into 0.91 and went back to using that.  It does not have this issue.  From what I've been reading it seems like this is most likely CPU starvation.  I've verified that it doesn't appear to be a command buffer issue.  I wonder if there there something in 0.92 that's taking more CPU cycles and the processor on the RAMBo is just not able to keep up.  Anyone have any thoughts or suggestions?

Repetier

First check free ram. 0.92 and 1.0 have more features requireing more ram. So if buffers were before just full then in 0.92 it might be too full. A full hang normally happens when the stack runs into variables.

For deltas we advice using a due based board whcih can have more buffers and mor eupdates per second and is still faster.

otherguy

I did notice something interesting when testing.  It seems I can cause a full hang by printing an arc at extremely slow speed (~1-2mm/s), the hang is usually accompanied by some corruption on my lcd screen.  The same print at normal or moderately slow speed will just stutter and pause a bit, but not hang.  I don't fully understand why slower print speed would be a factor.  Perhaps your idea about not enough free ram is to blame, at slower speed some buffers aren't emptied as fast and it ends up causing corruption?  Just a guess.

I have a Duet board on order and will probably just stick with 0.91 until it arrives.  If I have the time and inclination do any more tinkering with 0.92 I will post the results here.

Repetier

You know that duet is not supported?

otherguy

Yes, I am aware and that was something I considered long and hard before buying.  However, I decided to give it a shot anyway, and still hope that maybe someday in the future it'll be supported.