Question

how can I mount a 3" wheel on a motor with a 52mm dc motor

Answer 1

There are a few popular ways to fasten pulleys/gears to motor shafts, but like in most cases the perfered method is dependant on purpose. You should keep in mind the potential load the system will see while in use when figuring out what fastening method to use. Personally, unless the intended purpose is to run a little scroll saw or the like, I would default to using a keyed motor/pulley.

You may get away with a standard keyed system, but if you're "going big" with your sander, you may need to bump it up to a woodruff key, or even a keyed taperlock pulley. I think the first course of action is to determine the size of your sander and then spec the motor needed to drive such a machine. Odds are, the motor size will determine what you're going to need to do, to securely fasten the pulley.

Simple. Makes sure you know the size of the shaft on the motor. 1/2", 5/8" or 3/4" will be simple

The shaft may or may not have a "keyway" , (groove in the shaft) if it does, you want to get a key and pulley that fit it.

If the shaft is completely smooth, the pulley will have a set screw to hold it on . I suggest that you file a small flat spot on the shaft for the set screw to grip. It's not really necessary but helps

Stephanie simple pulley fastening is often done with a setscrew that screws through the pulley against the shaft, a flat spot on the shaft will help to keep it from slipping HTH