dial indicator back plate tool holder

This is a back plate for a cheap dial indicator that also has a quick change tool base on the back. The screw holes for my dial indicator are 33mm square (46.7mm corner to corner), and the outer diameter of the back plate is 53mm.

The back plate sits about 6mm away from the tool holder, because my base mount thing has a bolt on the lever that got in the way otherwise.

[OnShape document](https://cad.onshape.com/documents/de33ded0fcf7c2443633673d/w/dcf15e40641250eda2965634/e/04fa5613907eb5ac72e5558b)
(warning, the CAD is a bit of a mess...)