Router variable speed failure

[Rob Blaustein]

I was operating my Dewalt 618 router recently and had the speed set to around 4. In mid pass the router got much louder and higher pitched and I realizes that it sped up to full speed. So I appear to have lost the variable speed control. Is this a common way for routers to malfunction? Is it typically an isolated thing that is easily repaired or does this signal the end of the router's life? I haven't used the router much over the 5-6 years that I've owned it.

[David DeCristoforo]

This is why I have never liked variable speed tools. The "brain boards" crap out and they are not cheap to fix, even if you are lucky enough to have a model for which there are still parts available. Consider yourself fortunate that your router "defaulted" to full speed and not "no speed". I still have one of the original "five speed" PC monster machines. The "brain board" burned out after a few years of use so I "lobotomized" it and it has been in use ever since as a "one speed" router.

[David Perata]

Is your router a soft start? You can't use the variable speed boxes with soft start routers.

[Joe Spear]

Is your router a soft start? You can't use the variable speed boxes with soft start routers.

Nobody said anything about a variable speed box. The routers mentioned both have their own variable speed controls.

[Rob Blaustein]

I'm not sure I understand this--I believe the Dewalt 618 has a soft start feature and it has variable speed. I don't know what a variable speed box is.


Is your router a soft start? You can't use the variable speed boxes with soft start routers.

[Matt Day]

I think me means the cheap little add-on variable speed box from Harbor Freight, no?

[Curt Harms]

I'm not sure I understand this--I believe the Dewalt 618 has a soft start feature and it has variable speed. I don't know what a variable speed box is.

Porter Cable & Freud have an enclosure in the case that has the variable speed control wheel sticking out of it. There are wires going to the motor and to a speed sensing device. The DW618 is current production so you should be able to get replacement parts. The other option would be to run wires from the cord to connections on the motor out and use one these. (http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/speed_control.html) I have no first hand experience but would expect the factory option to be better, the external control to be cheaper. Of course for routers for which variable speed units are no longer available, the external box is the only choice.

[Paul Nienaber]

I read on another board that there is a round magnet under the speed control. Sometimes this magnet breaks, causing router to go to full speed. It is a cheap and quick repair if your comfortable taking your router apart.

Paul

[Rob Blaustein]

Thanks Paul, that's very helpful. If you recall where you picked that up I'd love to read more about it. I don't mind taking things apart as long as I have some guidance.
--Rob

I read on another board that there is a round magnet under the speed control. Sometimes this magnet breaks, causing router to go to full speed. It is a cheap and quick repair if your comfortable taking your router apart.

Paul

[Paul Nienaber]

Not sure if I can post a link to another forum here, so pm sent. Hopefully there's enough info there to help you out.

Paul

[Rob Blaustein]

Got it, thanks so much Paul. I think you're correct about not linking. Excellent discussion there at that other woodworking forum! Turned out it was the magnet that's part of the speed feedback control that cracked (it spins at the speed of the router shaft). Rick Christopherson correctly diagnosed the problem.


Not sure if I can post a link to another forum here, so pm sent. Hopefully there's enough info there to help you out.

Paul

[Mike Moe]

I had the same experience with a Porter Cable 7518, which is only used upside down. I removed it, remove the top and used compressed air to blow out the speed selector switch and the problem was solved.

[Rob Blaustein]

Well that's certainly easier to try--mine has also been mostly used upside down in a router table. Maybe some dust got in there. Good tip, thanks.


I had the same experience with a Porter Cable 7518, which is only used upside down. I removed it, remove the top and used compressed air to blow out the speed selector switch and the problem was solved.

[Rob Blaustein]

I opened up the router and it turns out that my problem was identical to the one discussed in the other forum that Paul referred to--a broken magnet that is part of the speed feedback control.

As discussed in that other forum, since the router still functions, albeit at full speed, the system has failed in a closed-circuit. According to Rick Christopherson, the most likely culprit in such a scenario is a broken magnet. As usual, Rick was on target. Now I just have to figure out how to remove the bearing to replace the broken magnet. I don't have a gear puller. Anyone have any advice on how one removes a bearing from a shaft without damaging anything?

[Simon Dupay]

I opened up the router and it turns out that my problem was identical to the one discussed in the other forum that Paul referred to--a broken magnet that is part of the speed feedback control.

As discussed in that other forum, since the router still functions, albeit at full speed, the system has failed in a closed-circuit. According to Rick Christopherson, the most likely culprit in such a scenario is a broken magnet. As usual, Rick was on target. Now I just have to figure out how to remove the bearing to replace the broken magnet. I don't have a gear puller. Anyone have any advice on how one removes a bearing from a shaft without damaging anything?

A bearing separator should work.