[Tom Lindsay]

Hi all! Was poking around on the web looking for some help with a router issue I'm having and came across this forum. I am in need of some guidance regarding a DeWalt 625 router that I own. The router had been working fine other that some occasional chattering, which got progressively worse. I ordered bearings and just finished replacing them; not too bad a job if you have a 2 prong gear puller for the old bearings. Got it all put back together, plugged it in and turned it on and nothing! No clicks, no smell, no smoke, nada. Bummer!

Took it back apart, and checked the wiring and everything looked ok. I used a multimeter to check the on / off switch, and that looked ok too. Pulled out the brushes again, and they looked ok too. Took an awl and an air hose to loosen up and blow out all of the dust particles I could get at as well. I am suspecting the speed control, which worked fine before I started my bearing replacement project. Now a disclaimer. I did take pictures of the switch / speed control / brush wiring as I did the initial disassembly for the bearings, but the quality of the speed control wiring pictures was poor, and I used another picture off of the web as my guide (lesson learned; check the quality of your pictures as you disassemble). This is how I have it wired right now.

I am not an electrician and I don’t quite understand the wiring of the speed control module? It has a hot and neutral going in directly from the switch, and also has a single red wire attached as well that runs from the speed control to the inside metal case? I am assuming the red is the variable voltage coming out, but that’s just a guess on my part.
I probed the brush connectors, which I would have expected to have some voltage to them based on the setting of the speed control, but they came up as 0. But, maybe that’s not the right way to diagnose this issue?


I am more than willing to probe the speed control connectors with the multimeter if that could help isolate the point of failure? Any suggestions? I am more than willing to order and replace the speed control, if I can demonstrate to myself that I'm actually replacing the right part ;-) Thanks in advance!

 

[biotec]

@Tom Lindsay

have you checked the brushes are placed correctly? #4 in #6

this should have been the last step shaft install. they are easy to break.

there should be tension on the wire in the brush. push against the motor shaft (Armature)

copper end lower right

 

[Tom Lindsay]

Biotec, Thanks for the suggestion. I had actually checked them when I did my initial reassembly and they were fine (not broken, good spring tension against the armature, wires connected). Just checked them again to be sure and they still look good. Based on the multimeter testing (touching each brush connector with the multimeter leads; reading a voltage of 0), I'm assuming the brushes are not getting any power. The other thing I had verified that was not in my original post was that the magnet that sits at the top of the shaft for the speed controller was still there and in good shape. Have read that these occasionally fly off and break.

 

[reuelt]

I would just use a jumper cable suitable for 15amps to bypass the speed controller.
If the router can run at full speed when the speed controller is bypassed with a jumper cable, then BUY a new speed controller.
(I replaced my Hitachi M12V speed controller after testing that my M12V ran at full speed with a jumper cable)

 

[Tom Lindsay]

Reuelt, Just tried the jumpering and the router did run at full speed. Many thanks! I had considered that, but wasn't exactly sure what to jumper, so I was a little concerned about frying something else in the router (again, I'm an electrical newb ;-) Will be ordering the speed control (looks to be ~$55). Still not 100% sure about wiring up the new one, for fear of frying it if I get it wrong. Hoping the new control comes with a wiring diagram!

BTW, great forum!

 

[reuelt]

Still not 100% sure about wiring up the new one, for fear of frying it if I get it wrong.

Don't take off the existing speed controller yet. The new OEM speed controller will be identical so just follow the exact wiring. If you cannot reach one end of a wire like my M12V, I just used an insulated wire connector.to join an cut existing wire to the same wire in the new controller.

 

[old55]

Welcome to the forum @Tom Lindsay

 

[jw2170]

Welcome to the forum, Tom.

 

[Rebelwork Woodworking]

I’ve replace 2 of these. It’s a common problem..

 

[old55]

Welcome to the forum @Tom Lindsay

 

[Ola C]

Don't know if any of my latest disassembly pictures can be of help.?

 

[4DThinker]

Dated thread, but bearing failure on these routers is due to bearings not rated for the top speed setting of the router. I've been using these Dewalt routers on 4 CNCs for the last 10 year or so and never had to replace bearings. I keep the speed setting one number down from the top. If the top number is 6 I set all the routers at 5.
4D