Quote Originally Posted by Diysurgeon View Post
Thanks, you were spot on. I tried to lower the sensor so it was closer to the plate but it made no difference. I then put a thin washer on the plate and as the sensor passed over it worked! the motor stopped. Obviously its not a micro switch do you know how this sensor works e.g. magnetic read switch or some other?

Thanks for your help I'm back up and running.

Now to work out how to fit a fourth axis.
There are many types of proximity switches but your type is an inductive type that senses metal causing a shift in a magnetic field. This explains better than I can.
https://en.wikipedia.org/wiki/Proximity_sensor

Regards the 4th axis then the last machine I converted had the 4th axis and it used a Custom driver Board which connected to the main driver board and talked to the Boxford controller. I would imagine it's a very expensive add on. The Boxford 4th axis was also very poorly made.