@Bogdan said in Steppers PID - NOT heaters PID:
(It may already be implemented in LinuxCNC, but I didn't look into the details).
for servos only.
I think you are missunderstanding the basics
"motor pid" is positioning them, with stepper that makes zero sense, you know where stepper is.
what's mentioned further is the way movement is calculated (constant jerk, trapesoid, S curve, junction deviation etc etc ..) and that's a completely different thing.. it's where 3d printing path calculators are behind some professional cnc machines but that's mostly 'cause it would bring nothing or close to nothing to 3d printing story (our lateral forces are pathetic compared to milling machines). we are much closer to engravers than to mills and you will not find these calculations there neither..
the ringing you mention has very little to do with this (nothing to do with videos you linked). maybe S shape will reduce ringing but that's minimal, ringing is caused by shitty parts used on most printers... GT2 belts used 'cause they can bend over a tight radius, but they normally stretch and that equals ringing... you can find glass enforced GT2 but it's rare, expensive and not mounted to any of the printers I seen so far (from prusa & ultimaker to super cheap PRC stuff) ... the new E3D machine supposedly comes with german GT2 that's reinforced, we'll see how it behaves when it arrives.. but look at your regular cheap popular printers these days (ender 5, ender5s, wanhao d9, creality cr10 etc etc..) there is a SPRING on the each belt!!!!!! there's no electronics that will remove ringing produced by those springs, the only thing you can do there is crawl to halt (reduce acceleration to nothing and jerk/junction deviation to zero )