Want2b,

There are two means of sensing in use for operation. the first is an IR reflectance sensor remote sensing the xy distances of the board and the other is an electrical contact sensor for the cutter tip for z distances.

The IR reflectance sensor at the base of the z-axis measures the length and width of the board and is coordinated with the brass tracker wheel to provide rectangular dimensions of the board. Vertical distances are determined by the difference between the tip of the cutting bit touching both the brass tracker wheel and the flag arm that swings out on the other side of the track belts from the tracking wheel. The final measurement prior to cutting is then made with a touchdown at the swing plate. This collected information is then used to evaluate the board prior to cutting for the correct cutter, dimensions, and design considerations prior to cutting.

To the best of my understanding, this is what I believe is going on.

Regards,
Jim