I know that heat could be an issue, but could having the pots adjusted too high throw off the cutting path…? I was having trouble cutting a job today and the only things I changed was 1.I installed the new DWP611 mount and 2.Increased the motor current pots. I readjusted all the belts and v-wheels too to make sure that everything was still properly tensioned after the new spindle mount install. But after three tries the job continued to cut wrong. The location and type of error was different on each attempt but it always occurred less than 10 minutes into the job. Sometimes within the first minute.
The pots adjust the current limit for the stepper motors. If the current limit is too high the stepper motor driver chips can go into thermal shutdown.
As the chip cools it will start functioning again until it gets too hot and then it will shutdown again.
The Arduino doesn’t know if the chips shutdown so it could still be processing move commands that the driver chip will not see.
So, having the current limit set too high could be causing your problem, or it could be something else entirely.
Try loading a complex job with lots of x, y & z movements and then ‘air-cut’ (raise the tool and leave the spindle motor off) while adjusting each pot.
It’s relatively simple to find the ‘too high’ and ‘too low’ points and to then leave each pot in the approximate mid point between these two extremes. Pretty-much, all you need to to do is (very gently) adjust each pot until that axis runs nice and smoothly. Once each motor is making a nice ‘clean’ whining noise without any ‘stuttering’ or harsh noises, you’re good to go.
It’s not terribly scientific, however it turns out to be reasonably effective.