Jobs ruined after long run

[JAZZCNC]

Hi Bernie,

Ok well you need to start by checking the machine from head to toe for any mechanical issues. Mostly likely cause would be binding or failing bearings etc.
Any of these and the motors will struggle and start losing position or worse case stall completely.
It's actually quite common for things like this to happen on long jobs that run at higher feeds where torque is starting to drop off. The combination of heat which causes binding and steppers working in speed range that can be affected by resonance can also be a factor.

If you can't find any mechanical issues and the G-code is correct then it's strong possibilty you are being affected by Mid band resonance. This happens like the name suggests when the motors are working around there mid rpm level which at 2500mtr/min then you could be approaching(depending on screw pitch).
If you are being affected by this then you have limited options. Changing the feedrate to lower or higher speed is an easy test to see if you can move the motors out the frequency range where resonance affects drives/motors. If it is resonance then you'll likely struggle to go higher before motors stall.

Next option and the one which is most likely to work is changing the micro stepping settings on the drives(If they have any). This can shift the resonance to different frequency which the drives can handle better.

Replacing the drives with better drives is the last option and one that will most likley cure the issue if resonance is your problem.

Checking all the wiring both on the machine and in control for lose connections is second thing to try after checking mechanical.

If you post the G-code by zipping it up or in txt file (don't post all lines on here) then I'll take look to see can bad code.