Variable Speed Control for Belt/Disc Sander ?

[Doug Shepard]

I got to wondering today if it would be possible to use one of those foot pedal operated variable speed controls (the ones marketed for router use) on a belt/disc sander. I've got a Delta Sanding Center 12" disc, 6x48" belt combo. Is this motor burnout problems waiting to happen? I was originally pondering this for low-speed (and temp) sharpening but think it would also be an advantage for better controlling the amount of wood removal for fine sanding.
Any thoughts?

[Steve Stube]

The router speed control is for universal motors (brush type) but not an option for 6x48. You have several options for regulating the speed on your sander but using your current motor with step pulleys is about it. Expanding sheeve and hydraulic variable speed drives will take additional horsepower probably requiring a larger motor. Other options are the use of a DC motor and controller or switching the motor out for a 3 phase AC motor and adding a VFD (variable frequency drive). How much is it worth to you to have variable speed?

[Doug Shepard]

.... How much is it worth to you to have variable speed?....

Probably not worth the cost. Thanks for the quick feedback. I had a hunch it wouldn't work or others would have thought of it and done it long before me. The step pulley idea might be worth looking into though.

Thanks Steve

[Steve Stube]

I have converted several shop machines to variable speed but not a 6 x 48 belt sander but that doesn't mean it's a bad idea - just haven't tried it yet. I do run one 6 x 48 at the slowest speed possible with 1725 rpm motor and the smallest pulley possible on the motor shaft. I haven't actually measured belt speed but it is slower than other units I have. It does a good job at slow speed and I get by nicely with only a 1/3 HP motor on it.

[Dev Emch]

Sorry Doug, it aint going to happen. The sander motor is an induction motor and the router is version of a DC motor called a universal. Speed control in an induction motor is available by controlling your AC line frequency. Doing this with a single phase motor is not a good idea!!!! Even with a three phase motor, there are quite a few operational caveats.