This gets stranger and stranger. I went to the sensor reading and pushed the truck across to see where it dropped to zero, the sensor was centered directly above the board edge, so much for a off set sensor. I then decided to see if I could run the sensor calibration. I put the tape on the board edge to fool the clear sensor. The unit went to measure the board width (OK) then it went to measure the length (OK) came back and then gave a Z axis stall........................OUCH