Working on a Bridgeport Interact 4 with a Heidenhain 155 control that will not home on the X axis. It will travel in the X+ direction as expected, but when the reference dog switch is reached it jumps rapidly in the X+ direction and trips out with usually a "gross positioning error D" message. Pushing the reference switch at mid travel will produce the same effect but will only travel less than half an inch before the trip out and error message. The X axis hard limit switch funtions properly. The switches seem to be working and there appears to be no wiring problem because the control is recognizing the switch signals. All four of the green LEDs on the axis drive board will light before the trip out. This machine came with no documentation and we are using a list of "generic" parameters. We changed the X axis drive motor and encoder with one from the "cannibal" machine, but did not improve upon the problem. The Y and Z axis work fine.
On the other Interacts, pushing the reference switch will reverse the direction of travel and upon releasing the switch will stop when receiving the next reference pulse.
Has anyone had this similar problem and found a cure? Thanks, Dan