Advice on building a grinder...

[Matt Benton]

I've seen a homemade, hinged grinder using a spare motor that was made by one of the contributors to FWW, Chris something, I believe. I was hoping to make a similar one using a motor I have, but I'm having a problem.

My motor has a threadless, keyed arbor, and I think I need a threaded one to attach the grinder wheel. Does anyone know how I could modify my motor to be able to attach a grinder wheel?

Thanks in advance!

[Jim Grill]

I've had run-ins with motors like this before. The shafts usually go all the way through the motor making it impossible to put a new shaft on or something way-too-easy like that.

Unless you know a talented machinist who has some free time, I think you are out of options with that motor. I had a machine shop make a special adapter for me once. It's not cheap for them to make something from scratch unless you need several thousand of them. :)

The only idea I have is to find a pulley that would fit and use a belt going to another pulley of the same diameter that would be attached to a threaded shaft for the grinding wheel. I think that kind of defeats the purpose.

[Greg Peterson]

If you are not able to attach a grinding wheel directly to the motor shaft, you might consider putting a pulley on the shaft and use a mandrel.

http://www.leevalley.com/images/item/woodworking/sharpening/68k0101s1a.jpg

[Al Killian]

My grinder is like the one Greg showed. Mine was made that way from the factory and dates to the late 30's.

[Matt Benton]

Thanks for both of your replies!

I'll probably end up going with the mandrel, as Ace Hardware sells one for @ $25. Just hoping to minimize the space needed.

Thanks again.

[Bruce Wrenn]

Grainger stocks an arbor to fit your shaft. Also have seen them at Lowes a couple years back. Some "better" hardware stores stock them, along with Surplus Center in Lincoln Nebraska. Before building a hinged grinder, as Curtis Erpellting (spelling?) did, look at a copy of Ian Irby's book, "Sharpening With Waterstones". He shows a couple of simple jigs for holding chisels and plane blades. The rest is a piece of round bar stock. I have adaped this design to both my home made and store bought grinder.