z axis skip, head going slowly down

Hi everyone,

I built my machine some months ago, did not use it that much but getting back to it now.

My z axis is starting to show issues. Basically during a long cut it slowly goes lower and lower. I guess there are skipped steps, but it is always in the same direction. The motor is skipping when going up, not down. Is it a pattern you guys recognize ? The material is really soft, foam.

I’m using a firmware from last summer, without lcd. This is the basic version of the machine, that I made myself. The laptop driving it is quite crappy, maybe that is the issue ?

Thanks for your help !


this is my kit: https://www.v1engineering.com/forum/topic/new-build-in-bordeaux-france/

This comes down to Rapids usually. Make sure you have a look through my estlcam basic and look at the rapids setting highlighted in yellow. Make sure not to exceed these speeds and you should be fine. The slower you move the Z axis the stronger it is.

The other issue is lube and how easily the z-axis moves when un-powered.

If you are still using the allthread I was wrong and we have switched to T8 leadscrew for the power and speed advantage.

Allright thanks ! I do have an allthread for now, just ordered a leadscrew.


Just in case somebody sees the same issue, I realized the fan on the stepper driver was unplugged, and this issue came from driver temperature reset… All good now.

Thanks for your help.

Have a look at your driver voltages, typically we do not need them high enough to need a fan anymore. 0.7V on a DRV8825, should be fine without a fan and a little high for most steppers.