Making Keyways

Grinding Exterior Keyway

Use cutoff grindger wheel and guide, then use a dremel to clean up:

Brute force with grinder:

Summary of grinder route:

1. Use cutoff grinder wheel with guide to make the sides. Use a guide clamped on the shaft. This provides the straight, vertical edge
2. Use a larger grinder wheel to bore out between the sides.

Internal with Grinder

• Doesn't really exist.
• Use a reciprocating broach, or parting tool blade if you don't have a broach
• Or, get creative:
• We can hack this by making a 'through keyway'. Does it exist? Closest is this - [1]
• Concept of through keyway - create an inner keyway - from the outside! By going all the way through

Broach

• Arbor press and broach is the industry standard.
• Keyway broaches add cost - $40 for a single broach [2]

Universal Axis

• Simply mount a needle file on a Universal Axis - based reciprocator, and let it CNC all night long to make a perfect keyway very slowly. With 10 micron step size, this should not be a problem. Working out functional parameters would be a good project for a student. Needle files: [3]
• The above is inspired by this:

Angle Drill

• Can we find a tiny angle drill?
• Harbor Freight 3/8" drill attach. If take off right angle chuck, may have a way to mount grinding disc. [4]