converting belt sander to variable speed?

Most of the 6x48's are pulley driven - step pulleys would probably be simple and fairly inexpensive to setup on it.
 
The current controller that KMG uses is an AC setup, so in theory, it would be "plug and play". The bad news is that those controllers are NOT cheap.
 
this may sound stupid and it probably is but what about integrating a adjustable light switch into the wiring of the electric socket. any idea if thats possible?
 
marekz said:
this may sound stupid and it probably is but what about integrating a adjustable light switch into the wiring of the electric socket. any idea if thats possible?
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May work fine, May also cause the windings to overheat if under a moderate to heavy load. I wouldn't use it to get a very low speed. Maybe use 50% of normal as the slowest speed. Also, speed control may be sloppy, dropping a lot at lower speeds.

I've used phase angle control (which is what dimmers use) on small-ish fans, and they seem fine with it, however they slip in the air easily at low speeds where a grinder may still see a high load. Also, most motors not designed for variable speed use class F insulation. I doubt insulation breakdown would be a problem with phase angle control, but something to keep in mind.

So, My suggestion would be to try this on grinder that you don't really care about. If it burns up, no big deal... ...if not great!

-Dan

P.S. I'd also add a few fuses, incase something goes wrong!
 
i have already tried the light dimmer method, with no luck the motor still wants to run at peak rpm. i thought myself that the dimmer would work. apparently not though
 
yeah i tried that earlier today before you mentioned it, you would think it would have worked but i quess its not as simple as it sounds
 
The variable speed setups that KMG and others use is a 3 phase AC motor coupled to a VFD that converts single phase to 3 phase and controls the number of cycles of the out put. You can also find some DC motors with variable speed set ups/ I think a single phase AC motor will be tuff to control. A lot of small fractional hp ac motors that have variable speeds use a different set up than the larger motors. Either brushes or several sets of windings.
 
Dimer switches and similar speed controls won't work on most motors that power simple ( cheaper) shop tools. The motor is the wrong type. If it were that easy, all such equipment would come as variable speed.
Stacy
 
There is a huge difference between a palm sander and a belt sander motor. The palm sander, drawing less than one amp, may run slower on reduced voltage, but will probably overheat if under load. The belt sander ,drawing several amps, will probably not work on a dimmer, and may burn out the motor if used under load.
Stacy
 
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