Try filing the top of the key a little to keep it from dragging on the gear hub. The key is more of an alignment device than an actual drive lug- - - -the press fit carries most of the driving load, so the key does not have to be a perfect fit in the slot. Also, a little anti-seize compound on the parts will help them slip over each other without compromising the fit. An aluminum gear can be heated to about 250 degrees and it will virtually fall into place- - - -I don't think I'd try that with a fiber gear, however.
Jerry



"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!