pic: Skunkswerve Module Iso View

[=Martin=Taylor=]

Originally Posted by Dave McLaughlin

Hal was a bit quick to insist that we are looking for an alternative to keyed shaft. We encountered a small problem with holding one of our keys in place, but we have already figured out a way to address the problem. Thank you for the quick suggestion of hex shaft, but we intend to stick with the keyed shaft we have now.

If it is machined correctly the key should have almost a press fit so it doesn't twist around. You can hold it in place by simply having spacers on either side of the sprocket/gear to limit its movement or by using a setscrew.

IMO keyways are MUCH easier to make than hex parts. You need a lot of special tools and skills to correctly machine hex parts. Keyways are very easy.