Stages of success...
Beevo converted his mid size CNC mill to a different controller. The trip was both enlightening and frustrating at times, but ultimately successful.
Upper Left- first test cut of a part. The part is a tail stock ram bracket for adding a small digital scale. MDF was used for this experiment. Other than the tab thickness, which was easily fixed in Sheet Cam, it came out as expected.
Upper Right- A metal version was cut and it looked a lot like this MDF version shown here. The job was cancelled after the second pass and a full run was made with MDF. The machine was moving in X by about 0.100" between passes.
Lower Left- the problem got progressively worse until this result. A check of the drive components for something loose did not find anything and would not explain why portions of the cuts were perfectly formed. The G Code file made to cut this part had previously worked without issues prior to the controller change. This is a good reason to think objectively when troubleshooting.
Lower Right- A partially shorted wire for the 5VDC output in the main power supply box is the suspected problem. The driver modules for the steppers were changed out, partially for this issue. The original modules were half step units and micro step units were added. This cut is the end result with NO changes to the G Code.