On Wed, 10 Sep 2008 19:16:35 -0700 (PDT), N Hurst
wrote:

On Sep 10, 9:53*pm, dpb wrote:
Purchase a pulley of the proper diameter and bore.

Any recommendations on where to go for one?

http://www.mcmaster.com/ (my preferred online "go to")
http://www.grainger.com (my preferred local "go to")
http://www.mscdirect.com
http://www.grizzly.com

etc.

or do a Google search for "sheave" any your city location and it may
bring up some local outlets.



Rather than a flat side section on the spindle like most motors I've
seen, my motor has a notch cut out of the spindle in which a small
square metal peg was inserted.

A square key fits in the notch and mates with a similar notch in the
sheave to prevent the sheave spinning on the shaft. If you check the
motor dataplate, find the frame size, and compare it to the entries in
a NEMA frame chart, it will give you the diameter of the shaft and the
dimensions of the notch. Or, since the key slots are standardized
based on the shaft diameter, you can just get one that matches from
the same place you get the sheave.

For example a motor with a NEMA 56 frame has a 5/8 dia shaft which
takes a 3/16 square key. See for example:

http://www.electricmotorwarehouse.com/PDF/NEMA.pdf


Any keyed sheave/pulley fitting that shaft would also have a 3/16
keyway. Here's an example

http://www.grainger.com/Grainger/items/3X896

Note the description and specs indicate that the sheave has a keyway.

A 12" length of 3/16 keystock from Grainger is about 95 cents if you
want to cut your own.

Tom Veatch
Wichita, KS
USA