Re: Keyways or set screws

> A tight-fitting key is very good.

Is that hard to achieve? Will I be able to get a tight fit with a
keyway broach? Does it take experience to use one properly? I don't
have a press, can a 9x20 lathe push a broach through aluminium?

> High-torque servo motors can loosen
> any setscrew, although installing two screws, one on top of the other
> has been a time-honored trick to keep them in place. Another scheme

is

> to drill a dimple into the shaft where the screw seats. The best

scheme

> is locking collars or collet hubs on the pulleys, although these can

be

> quite expensive new.

Yes, I've seen them. Gates make the perfect set of pulleys I was
looking for, unfortuantely the local Australian distributors don't
stock the particular series - they said they would need to import some
parts from the US and the others from the UK - free shipping would take
3-4 months, or I could pay $200 for air freight :(