With every Z setting device there is an offset distance. In many cases for the portable type this is simply the thickness (distance from the top to bottom) of the device. In others (mostly the fixed type) the offset distance is the distance from the top of the spoilboard to the top of the device.
Which ever version you use you can set up a second macro or script and simply enter the distance from the rotary axial center to the top of the device. or look at the attached graphic from one of my rotary training slides.
In this method you verify the height of the chuck or some other fixed object, and apply a user offset from the keyboard to that height.
Hope this helps, GC
CNC Technology & Training
The Ultimate Woodworking Machine
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