grinder motor quesions

[Winterbear]

So guys I need some help in simple easy to understand terms, even though I know the basics all I have ever messed with is AC. Gathering parts to build a grinder and came across a couple variable speed 1hp DC motors ( GE 5bpb56saa101) seller said they are tested and operational bidirectional and came out of a overhead coneyor system. Would one of these serve well as a motor for a 2x72 kmg clone and I assume I would need a controller and maybe a converter to hook into my 220 AC service in the shop does any of this sound close to correct?
Chris

 

[Sampson knifeworks]

Hi Chris, I think smaller DC motors usually are 90volts and they run on 110 Ac and the larger DC motors are 180 volts and require 220 Ac. The controllers convert AC to DC and most can be run on 110 or 220 by switching a connector inside the box. I am no electrical expert, but I have hooked up my own controllers to both 110 & 220 DC motors. Follow the instructions that come with the controllers, If you buy a used one make sure there is a manuel on-line to print out! Good Luck.
Clint

 

[BossDog]

the answer is maybe. a 1hp motor for a 3 wheel setup (contact wheel, idler, drive wheel) may work. for a 4 wheel setup (flat platen) probably will be a frustrating experience since you would stop it constantly under load and have to adjust to a very light grinding style. Also, DC motors lose torque as you slow it down. a 1hp DC motor at full speed has 100% rated torque, at half speed, half of your toque is lost also. It's not exactly 1 to 1 reduction in torque to speed but it's enough to be a problem. I run a DC 1.5 on my KMG and at 1/3 speed, I can almost stop it with even a 3 wheel setup.

 

[Winterbear]

Thanks Guys, I passed on these . Now next question I have a variac(spelling?) I salvaged from work and was wondering how it would work with a larger ac motor for a 4 wheel setup? Do you lose tourqe the same way you do with DC ?
Chris