Re: Souces of Timing/Drive Pulleys

J.S.,

I agree, it would be wise to match the taper standards of
commercially available parts.

I'm not sure what you mean about not being able to turn the pulley
taper first, tho'...

If the pulley is mounted in a 4 jaw, and indicated in... Then the
taper bore is made... Then a drill mounted to the crosslide/toolpost
is used to drill/ tap the holes in the pulley (using indexing of the
spindle)...

Doesn't matter which is done first, holes or taper. It is all
one "chucking".

The hub material is chucked up. Turned down to the major dia. of the
taper... Taper turned... Then the drill in toolholder is used, same
as before, to drill and tap holes as needed... Finally, hub is parted
off... Again doesn't matter if the taper is before or after the holes.

Hope this helps.

Ballendo

>Ballendo
>The hubs are quite cheap it's the pulleys that can work out
>expensive.
>You need to drill and tap the holes in the pulley BEFORE you turn in
>the taper as it's impossible to tap a hole 1/2 and 1/2 and keep it
>true. If you keep to the Fenner standards you can then change ratios
>at a later date with no problems and mix and match pulleys and hubs.
>J.S.