Drill Bit as an exercise

Here’s a drill bit I modeled. Mostly as a modeling exercise, but also to learn more about drill geometry. Drill bits are a bit more complicated than I expected. In particular, the chisel angle and the cross-section of the flutes are not immediately obvious and can be mathematically complicated (especially the flutes).

Anyways, don’t take the facet angles too seriously. Some angles are close to correct (30 deg helix angle, 8 deg clearance angle, approx 120 chisel angle, 135 deg point), others are just eye-balled.

I might try to create a guide for drill-bit sharpening, but I doubt I would come up with anything better than a Darex, Tormek, or Drill Doctor. But maybe some guide that could be 3d-printed for a silly hobbyist maker, like myself.

Maybe useful as a teaching tool for those learning to become machinists.

Drill Bit Geometry.stp (3.5 MB)