Jerk-limited movement?

[l29ah]

Seems like it is impossible to limit the motor jerk in machinekit at the moment. What would be the easiest way to hack it in?

[ArcEye]

Impossible to comment on without more detail.

What exactly do you perceive as the problem and what is your solution?

[l29ah]

I have to limit speed and acceleration a LOT to avoid sudden stepper skips and failure to accelerate/properly decelerate(?) on my trapezoidal screw-driven cnc mill, that is especially sad occurring a few hours into the 3d printing job. I was suggested to limit jerk by 3d printing people, so i decided to give it a try.

[ArcEye]

..........so i decided to give it a try.

What did you try? Or is this you trying?

If you are aware of some code which works, then link to it.
AFAIK linuxcnc has discussed this ad infinitum but has never been able to implement it.

A general solution might not work for CAM code anyway, which is generally made up of lots of little sections, with acceleration and deceleration within a very short time.
People tend to ramp up their acceleration and velocity way beyond what the rigidity of the machine and capability of the drives is capable of.
They get away with it because moves never last long enough to reach full speed.
If / When they do, they loose steps or position due to flex or crash and burn some other way.