This will allow you to temporarily mount a standard dial indicator (with mounting lug) onto a 52mm CNC spindle to aid in leveling the spoil board relative to the machines XY axises. I used a 1/4 inch screw and nut to mount the gauge to the clamp, a #10 or a M4 or M5 should work just as well. The thumbscrew uses an M3 screw and nut. A 1/8 inch screw should also work, but you may need to set the nut with a soldering iron.

I am sorry, the thumb screw shown is not included. It was one I had in my screw jar, but there are plenty of knob generators on Thingiverse.