[ebarker]

My strong suggestion for FRC usage is to get the pulleys with set screws, preferably two set screws 90 degrees apart.

The using a good arbor press and keyway cutter, cut a keyway inside the bore and put the keyway directly under one of the set screws.

Then you can put it on a shaft with a key.

Some caveats. You will need a keyed shaft.

For example for doing 1/8 keys on 1/2 shaft we use the following parts from McMaster. The reamer is to size the bore. You may not need that. The broach and bushing match each other and is used to make the keyway. You will have to mill a keyway on a shaft or buy keyed shaft from McMaster. If you want a hex bore, you mill it yourself.

3106A42 High-Speed Steel Chucking Reamer, 1/2" Diameter,.4355" Shank Diameter, 2" Flute Length McMaster 1 $27.06

3153A16 Keyway Broach, Uncoated High-Speed-Steel, 1/8" Keyway, Broach Style A McMaster 1 $42.06

3151A115 Keyway Bushing for Broaches, for Broach Style A, Collared, 1/2" Diameter McMaster 1 $9.85

We are going to be having some workshops on this side of town and if you are interested we can demonstrate.

BTW - those tools above I keep locked up to keep untrained monkeys from making it as useful as a banana peel.

In general purpose usage, pulleys are bored much smaller than the final usage. Typically machinists bore the pulley to nearly proper size, then ream it with a precision reamer (above) and then make the keyways.

Pressed on bushings/pulleys/hubs when done properly are done with high pressure hydraulic presses Some stuff I've done in the past (not FRC) have used 60 and 100 ton presses to remove the hub.

In the past in FRC we have gone without keys but filed a flat spot on the shaft for the set screws to land. Really ghetto and only is useful for FRC robots with minimal loads or stresses. It requires constant maintenance is and a pain.

Ed