Slowing a belt sander down

[ricklee4570]

Im posting this for a friend. He has the Harbor Freight 1x30 belt sander and he is sharpening knives with it.

He has become pretty good. However, he is wanting to slow the belt down for some more intricate work that he wants to do.

Is there anyway to reduce voltage or add a different pulley to slow the belt down? If not, what would be the cheapest variable or slower 1x30 tabletop belt sander out there?

Thanks!

 

[oronocova]

I would also like some input on this exact question... As I understand it you need a motor made to be variable speed to vary the speed without damaging the motor. I tried this myself with a dimmer switch and ruined a cheap grinder once.

I wonder, though if you could use a pedal off an old sewing machine or the like. I'm not sure if that would also damage the motor since it would be just on/off/on/off/on/off... IE when the motor was running it would be getting the correct voltage just doing it in cycles.

I looked into it a while back and you can also get devices to control a motor that use something like Pulse Width Modulation which to my understanding do the exact same thing as the pedal I mentioned just much faster. They are expensive and I'm not sure if they would damage the motor or not.

Hope someone else has some better info, I'd like to know the answer to the same question.

 

[Noumenon]

I think someone has posted this here or elsewhere but depending on what type of motor your grinder is, this should work.

http://www.contractorsdirect.com/Variable-Speed-Control

 

[ricklee4570]

I found this as well: http://www.harborfreight.com/router-speed-control-43060.html

Im not sure if it would work with the belt sander though.

 

[65535]

If you want variable speed, you'll need a 3PH motor and controller, 1PH motors are not designed to be run below full speed and they don't do well.

You could get a lower rpm motor for the grinder, or you could set up a jackshaft and use pulleys to slow it down.