Question about Saws

1 Answer

Electric Motor Question

Hi. I have a 500W variac (auto transformer) and I wish to purchase an electric motor that I can use the variac to regulate the speed of. Many electric motors won't slow down if you lower the voltage, instead they run at the same speed, sound quieter, and, when the voltage drops below a certain level, draw heaps more amps, but stop working. I have read on the internet that a 'shaded pole motor' will work on a variac, but what about a 4 pole motor? Any advice would be appreciated. Thanks

PS Excuse the strange product category, but I had to enter a valid product.

Posted by on

  • DrSpook Nov 12, 2009

    Your variac will control the speed of a bushed motor, so long as the wattage of the motor is 500 or less. Shaded pole motors are generally low power motors, such as the type used in electric fans, and will be no good for any heavy work. Induction motors are 'brushless' motors, and can only be controlled by lowering or increasing the frequency of the power. Brushed motors are cheap if you get them second hand or reconed. Hope this is of help.


1 Answer

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer


Posted on Feb 27, 2009

Testimonial: "This was helpful. I have since learned from a friend about motors, and he posted an answer on my computer, added as a comment!!! Thankyou for your ans"

1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

I have a Hitachi c 10FS sliding compound mitre saw that won't spin. I can hear the motor trying to go but no action. Could it be the brake? Ceased berring?

The brake is incorporated into the motor field - highly unlikely to be the problem.
If the motor is turning but the blade is not then I would be looking at the belt or possible stripped gear at the arbor.
If the motor hums or does not turn it most likely is the front armature bearing.
The C10FS is not an easy tool to service - the entire thing has to be torn down to get to the bearing, I would recommend bringing it to a reputable shop in your area.

Apr 06, 2015 | Hitachi Saws

1 Answer

Unit has stopped working, checked brushes all ok motor moves freely ,no power

measure the contacts over the 2 coils of the electric field sometimes if there was a faltering powercable the pulsation from the coils was to heavy and then by the field the winding wire can also be broken important by broken wire on electric field , test in all cases always the power cord to stretch test

Mar 18, 2015 | Saws

1 Answer

Makita ls 1211

The 'brake' on tools like this is actually a function of the switch allowing some current to flow to one side of the armature to magnetically stop the motor & blade. If the motor works fine but it is no longer breaking you need a new power switch. You need Makita part number 651923-1 for an LS1211 saw.

May 21, 2012 | Saws

1 Answer

The motor is running slower and the engine begins to smoke as if it is burning up. A suggestion was to replace the brushes.

It sounds like some oil has gotten onto the armature of the motor where the brushes are. That will cause the symptoms of what is happening.
Get some Electric Motor and Brake Parts Cleaner at an auto supply house. Note: It is not flammable.
If you cannot find it. Get the Regular Brake parts cleaner.
1 Allow the saw to cool to room temperature.


3 Spray the cleaner it into the vent holes
4 Carefully remove the brush caps (Small Black things that look like buttons) There are two of them.
5 Spray inside where the brushes are.
6 Let it dry out for a day.
7 Re-assemble
8 Plug it in and see how it works.

If it is still running roughly after you do the above steps. Get it serviced. There is damage to the armature and brushes.

Hope this helps.
Best, Mark

Dec 31, 2010 | Dewalt DW364 7 - 1/4'' Heavy Duty circular...

1 Answer

Can you please tell me if the plastic fan at the back of the motor can be replaced thank you best regards. john.

You can, but you'll have to purchase from an electric motor distributor. I don't know the exact motor that is in that machine.

Part Number 596141-3 is the entire motor assembly which is only around $65.00. Pretty good investment for a tool that is still retailing around $400 with the added assurance of a warrantied part.

Feb 12, 2010 | Makita 10" Dual Slide Compound Miter Saw...

1 Answer

How do I replace brushes?

two black brush caps either side of the motor - unscrew them pull old brushes out and replace. go to www dot carbonbrush dot com for replacements. or look to eurton electric for brushes.

Oct 26, 2009 | Black & Decker CS1012 7-1/4" 12 Amp...

1 Answer

Chicago Electric 4'' table saw. I used it to cut 1/4 inch wood then turned it off and it will not turn back on. I tested the outlet that I had it plugged into and the outlet works. I let it set for over an...

inside the motor is a thermal fuse. once it blows nnthing will work. the thermal fuse is within the winding. get another fractional horsepower motor replacement from grainger.

Oct 17, 2009 | Saws

4 Answers

KS850 circular saw 'burning' & smoking

The brushes in the electric motor have failed..
And sounds like bearing are shot too..
The motor is shot..

Thank you for posting your question on
We are helping people on a points system.
If the information provided here was at all helpful,
please be kind - rate well and close the post.
Thank you – and enjoy your day ;o)

Aug 01, 2009 | Saws

Not finding what you are looking for?
Saws Logo

Related Topics:

134 people viewed this question

Ask a Question

Usually answered in minutes!

Top Saws Experts

Tom Chichester

Level 3 Expert

26238 Answers


Level 3 Expert

63990 Answers

ray gallant

Level 3 Expert

37682 Answers

Are you a Saw Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides