Thread: grinder build motor question

Slow is good, especially after the blade has been heat treated. Mine is about 1700 rpm's and I can't remember the exact drive wheel size, but I think it's about 3.5". With my 8" contact wheel, you can see it going round and round if running nice and slow.

Speed kills razors and knives...

Slow is better. I rarely run my grinder at full speed. Any grinding mistake or un-evenness is magnified with the speed. Slow -> even grinding. Fast -> error prone.
Besides, I've found slow grinding to be fairly fast as well, because you give the 'teeth' more time to sink in, and belts will wear slower due to the decreased heat and decreased mechnical impact.

Adam,

I like the slow grinding too. I have the Hare and Forbes motor (1HP) 1450rpm single speed with the 4 speed pulley. I don't like grinding on the fastest speed at all, not even for the rough grind. I would actually like to go just slightly slower than the slowest pulley combination with the finer grit belts.

Stu

How about a washing machine motor Adam any options there?

I pretty much agree with all of the above. My rig is variable speed. I have gone as high as 3000 rpm for rough grinding before heat treat, and some of the other things I use my belt grinder for, but most of my grinding is 1000 or less - much less post heat treat. I think you have all the info you need now to get that puppy spinning. Good luck, and keep us informed.

Originally Posted by Substance

How about a washing machine motor Adam any options there?

Afaik, washing machine motors don't have enough power.

Thankyou All.
Really appreciate the info. Slow it is.
Regards,

DC motor with a controller. You can run it from barely turning to SMOKING fast. You can even reverse it if the controller is set up right.

After fighting belts and pulleys on mine, I'm going the DC motor route. Buddy of mine is a wizard that works on mail sorting machines and has a pile of motors. He's gonna rig my 2"X72" belt grinder up for me.