On Tue, 04 Sep 2007 18:11:21 -0700, Tim Douglass
wrote:

On Tue, 04 Sep 2007 23:04:00 GMT, (Doug Miller)
wrote:

In article , Tim Douglass wrote:

Now I have in hand a proper cast iron pulley. The shaft and bore both
are supposed to be 5/8", but I still can't get the pulley to go on. So
what do I do next? I'm thinking that I could heat the pulley with my
heat gun then slip it quickly in place, but I'm not sure that will
really work. Otherwise I could buff a few thou. off the shaft - it
seems to be a bit rough, so that might be a good idea anyway.

Agree with Upscale that if you're going to mod anything, it should be the
pulley arbor and not the motor shaft.

Do you have access to a good dial caliper, to measure the OD of the shaft and
the ID of the arbor? You may have a 16mm motor shaft (0.6299") instead of
5/8".

I went after them with my better dial calipers (the ones I use for
reloading rather then the shop ones) I got .625 for the pulley and
.627 for the shaft. That is probably within tolerance for the
low-budget-no-name Chinese motor maker. The shaft is pretty rough -
like it wasn't final ground after the lathe or something.

First, run up the motor and touch the shaft with a strip of emery for
a few seconds while it is running. That will knock off the burrs,
nibs, and even out the natural machining lobes to make it more "round"
.. It won't hurt it, but it won't remove much material if it is at the
correct hardness. Then make sure the pulley is chamfered on the end
of the bore, if not do so. if it still won't go on, gentle heat to
the pulley.

Frank

If they're close (within a couple thousandths) you can pop the pulley on by
heating it -- but probably not with a heat gun. Think torch, and heavy leather
gloves.

That's what I wondered, just how hot I would need to get things.

If they're not close... what you do next depends on what you measured with the
caliper. If the motor shaft is really supposed to be 5/8 (0.625) and it's
actually 16mm, either you take it back to the point of purchase, or you get a
16mm pulley. If the pulley is undersize, you could ream or bore it out.

I don't have the equipment to bore out the pulley that precisely, but
wouldn't be hard to take the shaft down those couple thou. with some
silicon carbide paper and a metal backing block against the spinning
shaft. I'll think about it a bit and see what other suggestions crop
up on here.

Thanks all.

Tim Douglass

http://www.DouglassClan.com

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