Hey guys,

I have a Dremel 100 which is a single speed rotary tool. I would like to be able to control it's speed because it's not always best to use it on full blast.

I've read one thread over at the EEVblog forums that one person said that the Dremel rotary tools use a universal motor and can be controlled using a light dimmer you can get from the hardware store.

I did try to contact dremel if this tool has a universal motor but they haven't yet responded.

That person from the other forum has a pretty high post count so I think he know what he was talking about.

So what do you guys think? Given that this tool is equped with a universal motor, can I use a light dimmer to control its speed?

 

Well the reason I asked is because light bulbs are resistive and a motor is inductive.

I don't know if it will damage either the dimmer or the motor or both.

Is there a reason why a universal motor would work with a dimmer?

 

You can also get the fan controller type 'dimmer', they are all basically the same in design, usually the motor types, especially Universal often have extra suppression etc.
The worst that most likely can happen on failure is the Dremel will run at full rpm.
Max.

 

You mean those ceiling fan speed controllers?

 

You mean those ceiling fan speed controllers?

Yes, if you Google dimmer or Traic circuit, you will see many simple designs to get an idea how they are constructed.
Max.

 

I have something around here which was made for that, but I'm not sure what's in it. If you Google "router speed control" you'll see it. It's a little black box with a knob and an on/off/variable switch on it. I think it ran twenty bucks or so at a mail order woodworking place.

It wouldn't surprise me if it were just a dimmer in a box though.

 

Its cheeper to buy a Adjustable voltage reg PWM AC motor speed controller 50V-220V AC 10Amp for $3.43 freight free from Ebay. I have used them as motor speed controlers.

 

Its cheeper to buy a Adjustable voltage reg PWM AC motor speed controller 50V-220V AC 10Amp for $3.43 freight free from Ebay. I have used them as motor speed controlers.

Are you sure these a PWM? Usually you would see a IC such as a 555 and some large power capacitors and a bridge?
They resemble a triac phase controller?
I checked their ebay site, and they appear to be taking license with the term PWM in the normal definition?
Max.

 

Your right Max, they are taking licence with the description. Its just a triac type Dimmer/ Speed control. But they work & a reasonable price, hardly worth making your own.

 

just buy this somewhere and it will solve your issue, no need to "re-invent" the wheel so to speak.

http://www.harborfreight.com/router-speed-control-43060.html

 

15 amps is a little OTT for a a Dremel?
Max.

 

BTW, I forgot I'm from the Philippines (SE Asia) so I buy my stuff mostly from eBay.

I'll just get one of these:
http://www.ebay.com/itm/1-pc-Lighting-Control-Dimmer-AC100V-120V-800W-Taiwan-/140519463162

Or this (it says for incands only but what the heck):
http://www.ebay.com/itm/390739211424

Both seem to be just rheostats.

 

15 amps is a little OTT for a a Dremel?
Max.

for $20.00, cant beat it, it may be a bit overkill, but you can also use it for other tools if needed be.

 

BTW, I forgot I'm from the Philippines (SE Asia) so I buy my stuff mostly from eBay.

isn't your mains voltage 220 over there? ( I grew up in Angeles City, Pampanga).

 

Hey!

Yep its 220V. I have a 220v to 120v step down traffo and a 110v computer voltage regulator. I could use either.

I suppose I could use either of the two ebay links I posted aboove?

 

I would probably choose the first one, just because it can handle higher wattage, and seems more durable.

 

Okay thanks for the help guys!

Edit: So I basically have to put this inline with either the hot or neutral line, right?

 

Hey!

Yep its 220V. I have a 220v to 120v step down traffo and a 110v computer voltage regulator. I could use either.

I suppose I could use either of the two ebay links I posted aboove?

If ebay, Why not go with the ones in post #8?
Max.

 

Okay thanks for the help guys!

Edit: So I basically have to put this inline with either the hot or neutral line, right?

I've never worried about any polarity with dimmer switches.

 

If ebay, Why not go with the ones in post #8?
Max.

Tell me, why should I choose one over the other? Pros and cons?