Quote Originally Posted by Husky1 View Post
The holes positions have same error, so i assume it is worn leadscrew / nut, but when i move the x axis by hand, i dont feel any movement, so i wonder, is this mechanical error or is there some electrical issue? i use chinese servo motors (bst motion, krs?? 400w) and cslab csmio ips controller.
If the drives were tuned correctly and you changed nothing and the error is repeatable then it's a most likely mechanical issue. However, I'd expect you would feel 0,5mm easy enough. That said it's the first place I'd go looking before started messing around with tuning. Set the drives to show current and see if they pull higher current than usual or in different parts of travel, they could be binding in one spot and causing the motors to fall behind slightly but then catch back up, this wouldn't fault the drives but the error would still show on the part.!

After this, I'd look for loose electrical connections. Then move onto re-tuning the drives.