Anyone put a dimmer switch....

B

bigretic

Joined
Apr 7, 2008
Messages
423
on a Work Sharp?

I've been doing it for a bout a week.Been getting outstanding edges w/ freehand.

Just curious if anyone else has done this?
 
A dimmer switch ... to slow it down? I thought it has variable speed anyway?
 
Probably the original model, which was one speed.

If the motor's not designed for it, it'll burn it out eventually.
 
Dimmer switches work by effectively reducing the AC input voltage (normally 110-120 VAC at the plug). For light fixtures, usually not a problem. For most electric motors, that's another story. If the motor is designed to run only on 60HZ 120 VAC (check the nameplate on the unit), reducing the input voltage will create a surge in current. The motor draws more current in an attempt to maintain the same electrical 'load' (for which it's hard-wired); the higher current will overheat the tool's power supply and/or motor, and damage it or shorten it's life. Almost certainly will void the warranty as well, if the tool wasn't designed for such use. If it's already got a speed control (which works by reducing the rectified DC output of the tool's internal power supply, for which it was designed), all the more likely the dimmer switch on the input voltage may do more harm than good, in the long run. Some heavy-duty tools may have enough overhead to absorb the extra heat generated by reducing input voltage, but it's generally not good for the power supply and/or the motor, unless it was specifically designed for it.

This is quoted from the WS user guide ( http://www.worksharptools.com/media/mconnect_uploadfiles/w/s/wsktsuserguide.pdf ):
"Motor
Be sure your power supply agrees with nameplate marking. 120 Volts AC
only means your tool will operate on standard 60 Hz household power. Do
not operate AC tools on DC. A rating of 120 volts AC/DC means that your
tool will operate on standard 60 Hz AC or DC power. This information is
printed on the nameplate. Lower voltage will cause loss of power and can
result in over-heating."
Click to expand...


David
 
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I was going to do the same thing with my first HF 1x30 belt sander, but when I went to the hardware store to pick one up the dude there told me basically the same thing David posted above. I wouldn't suggest it.
 
Yep. Alternating current motor speed controls are not as simple as a dimmer switch. It's complex enough that people have machined pulleys to slow down those cheap belt sanders rather than deal with doing it electronically.
 
You might use a motor speed switch, like those designed for high mounted ceiling fans. I have used one for years to control a duct fan to move heat from one room to another. BUT, I'm not sure it will work in your application. I'm thinking that the power reduction may cause problems on a power tool.
 
dimming equals heat. I would say that you could make it all work, but not without re-wireing everything, and that is something I don't know enough about.
 
If there was a quick cheap easy way to put a speed control on a grinder, it wouldn't be such a big deal. It's not trivial.
 
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