I have an interesting problem on Beaver mill with a TNC145 control. If you try to reference the Z axis it runs to the home switch, reverses and finds the index as it should. Once it finds the index it then runs away at full speed and trips out a gross positioning error. The same happens with the Y axis but not X.
I swapped Z and X encoders with no effect. I have also swapped the axis drive boards. Anyone seen this before?