Drill bit sharpening block with relief angle

This block serves as a guide for a grinding wheel (use wheel side) or a hand-stone when sharpening drill bits.

Despite the simple design and the ease of use, sharpening precision is very good.

Main characteristics:
- Ability to firmly hold the bit in place by means of two M4 screws.
- You can sharpen both sides without re-positioning the bit, making it easy to get almost-perfect symmetry.
- Guide line to help with bit positioning.
- The block has two faces (top and bottom), to hold two different angle combinations.
- You can print adapters to use the same block for different bit diameters.

You can change OpenSCAD parameters to modify:
- tip (lip) angle
- relief (clearance) angle
- bit diameter (though it is probably easier to use adapters)
- block size

I included stl files for:
- block 118° and 135°, 12° relief, 10 mm bit
- block 118° and 135°, 8° relief, 10 mm bit
- adapters for 2-3-4-5-6-7-8-9 mm bits
- handy angle gauge

Infill 20% is sufficient.
Holes