Milling is slipping

I hope you can understand even though my english isn´t that good…

I have som problem with repeatability.
I have set an startposition for my mpcnc, but the coordinates is sometime a little off, up to 1mm off. I need to get that spot on every time…

My other problem is that sometime the milling slips a little when it goes down deeper in the wood.
For each layer the milling starts a little bit off… See picture.

These things should all be included in your post. It makes it much faster to diagnose problems.

  1. Did you buy everything from here?
    a)If you didn’t or changed some things please don’t leave out any details.
    b)What firmware?

  2. Are you using end stops?
    a)If so please disconnect them.

  3. Are you using all my recommended parts?
    a) If not please list what parts you used.

  4. Include a picture so obvious errors might be spotted.

  1. Did not buy from you since I live in sweden and the customs taxes would make it very expensive…
    a) I have bought comparable parts
    b) Downloaded the firmware from your site (where do I find the firmware number?)
  1. Yes uses endstop to set startposition when switching bits. The problems is showing up even under the same milling session

  2. Yes I use recommended parts

  3. se attached image

It´s like the stepper motors count wrong or that they drop steps - but I have set the motor to quite high voltage (0.750 amp)

Move your zaxis it’s full range of motion by hand and see if there is any binding.

The new firmware has slower Z axis accelerations that might help if you are on old firmware.

You didn’t give specific information or pictures so that is the best I can do.