I have a homebrew router, 2X2 cutting area. It is stepper driven by means of Gecko 201s. The steppers are old compumotors by Parker. The control is DeskCNC. I have a large knee mill and plasma table that are under DeskCNC control also. I have had a problem that I have been working on for a couple of months off and on. I first thought it was electronic in nature and rebuilt from that standpoint. It was still problematic. I then rebuilt the mechanics. It is still not performing very well. Sorry about the long lead in to the problem.
The problem is in the Z axis. It always errors incrementally in Z in the positive direction over time. If there are few moves in a project, there is little Z error. If there are a lot, like in the stl file that I have been trying to cut, the error becomes so excessive that in a couple of hours the machine has risen above the work and is cutting air.
The stepper motors are old, I am guessing 80's vintage. I have swapped motors and drivers with other axis and have not been able to nail it down.
I was thinking about swapping cables but I cannot think how that could be uni-directional.
Any ideas would be greatly appreciated!!