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)


Hello @Anthony_Yan, I’m highly interested in designing geometries. Could you guide me on how to get started? Also, I’m curious if it’s possible to design them using Grasshopper.

Hi Mr.Ralf,

If you are interested in drill bit geometry, then I would suggest Googling about it. I can probably find a few links I used, but I don’t remember them off hand. Drill bit geometry is surprisingly complicated, and I wouldn’t be good at explaining it.

It certainly is possible to use Grasshopper to design drill bit geometry. I haven’t done this, but clearly it is possible. But you would need to have a good understanding of drill bit geometry before you start.

If you are interested in Grasshopper in general, then you can find some tutorials on the Rhino3d.com website:
Rhino - Learn to use Rhino

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