Tracking down stuttering (deb-12, LinuxCNC-2.9)

Thanks, I'll try halscope next time I have a chance to debug the machine.

I'm seeing the same issue with wireless or wired keyboards and do have a spindle encoder (the spindle on this machine is a 3.5hp servo).

Ah, maybe  add a 7i73 for MPG support once you get past this current hurdle. keyboard jogging is not something I've ever really done until recently.

I didn't see any following error and don't think I'm loosing steps. It might just be the cheap stepper drives (this machine uses generic TB6600 drives as standard -- they are about $10ea on Amazon). I ordered a nicer Leadshine EM542S drive for X to see if it makes things smoother, if so I'll upgrade to those on Y1 and Y2 as well.

New drivers made all of the difference. Life is too short to try and debug cheapo ones.