will a dc motor work?

[beochie]

after reading a bit I saw a few guys using DC motors to power their grinders how are they doing this?

 

[Jack O'Neill]

They are variable speed , the controller converts the a/c to d/c .

 

[beochie]

Thanks I google'd it found a ton of info

 

[beochie]

will this one work?http://www.auctiva.com/hostedimages/showimage.aspx?gid=997465&ppid=1122&image=285494566&images=285494440,285494498,285494566&formats=0,0,0&format=0

 

[John L]

It looks like a treadmill motor. You may use this but the true Hspwr is much lower than 3.

 

[beochie]

yea thats kinda what I thought but I'm overwhelmed with info trying to spec one out

 

[somberbear]

https://www.surpluscenter.com/item.asp?UID=2009071720574380&item=11-2102&catname=electric

one of these.... and a large motor i got from a surplus yard run my milling machine... its great... i cant get 3 phase , and single just makes things choppy.... only draw back ... the large perminate magnates have magnitized my machine.....

i been thinking of building a couple grinders or belt grinder some time....

 

[logem]

https://www.surpluscenter.com/item.asp?UID=2009071720574380&item=11-2102&catname=electric
[\QUOTE]

That's basically the same drive that I have controlling my grinder with a permanent magnet 2-hp Baldor motor.

I wouldn't recommend a treadmill motor for a grinder application. They are generally rated with higher horsepower than they actually put out, and are not rated for the same type of duty factor. In essence, they are disposable motors.

A good DC motor will cost well over $1000. The only way to go this route is to pick up surplus motors or find a good deal on eBay. I bought both of my DC motors there and payed under $200 each, including the controller.

Here's the motors I bought:

MOTOR SPECS HERE

Mike L.

 

[Stacy E. Apelt - Bladesmith]

I like DC drives and motors. I have used them for years without any problem.
The other option is a 3 phase motor and a VFD. Either way, the drive is often the bigger expense. Good motors (TEFC) of either type are available on ebay and other places cheap. Make sure the drive is matched to the motor. Forget treadmill motors for most shop uses.

DC drive, or 3Ph VFD -either one - once you go variable speed, a whole new world will open up to you.
Stacy

 

[somberbear]

i can barely remeber. but isn't one of the draw backs of dc , that as you reduce speed you also reduce power(torque/hp)?

its not been an issue for me really... just a thought....

 

[J.D.]

Do you need 3 phase power, to run the 3PH motor with a VFD?

 

[Don Hanson III]

3ph motor w/VFD uses single phase 220v.

i can barely remeber. but isn't one of the draw backs of dc , that as you reduce speed you also reduce power(torque/hp)?

This is true but with a good controler, it's not noticed and the HP is not need at slow speed with finer grit belts.

K&G had 1.5 hp DC leasson motors dirt cheap a while back. Ebay's usually a good place to find a deal also.