I made a simple robot to perform precision grinding and lapping on a drill. This setup is cheap and despite not being CNC, it tests well. Accurate to within a blonde one, just like the MERCH!✪►https://www.etsy.com/ca/listing/464202928/one-rule-to-ruler-them-all-cheeky-jokes◄✪ Experimenting with gauge blocks https://youtu.be/gbsd2OpPOMw