A sharpening jig for small drill bits. Designed for drill bits with diameters of 1, 1.5, 2, 2.5, 3 mm. It will form a point angle of 118° and a relief angle.

With this jig you can precisely and symmetrically sharpen both lips of the bit, and you don't need a Dremel or a bench grinder. Sharpening is done with a 180 grit sandpaper on a flat surface.

Concept:

There are many drill bit sharpening jigs on Thingiverse that only constrain the point angle, so the relief angle depends on how you position the cutting lip. Without a constraint on the relief angle your drill bit may not be functional or may have a wrong point angle (yes, it has an influence on the point angle too). I needed a jig for small drill bits, where it's hard to see how the cutting lip is positioned during sharpening, so I made this jig that lets you verify the correct positioning before sharpening.

Usage:

1. Inesert a bit into the matching hole
2. The cutting lips must be parallel to the guide lines
3. Make sure the cutting lip is only a little (~0.1 mm) higher than the jig's surface
4. Gently tighten the screws
5. Grind one face of the bit on sandpaper until you feel you're not grinding the bit anymore
6. Grind the other face

Notes:

I wanted to make an adjustable version of this jig, for arbitrary drill bit sizes, but I made a superior 4 facet sharpening jig for the same price. https://thingiverse.com/thing:4005898