Router rebuild question

[david brum]

I've got two Dewalt DW618 routers. One runs perfectly smoothly with no vibration(router 1). The other vibrates a bit, so it sound different and doesn't cut as smoothly(router 2). I just replaced the main bearing on router 2, hoping that it would take care of the problem. It runs slightly better, but not as well as router 1. I can't stand it!

Here's what I know: Router 2 has what appear to be good condition brushes. I did file the shine off of the surfaces in an early attempt to get it to work better. The armature appears to be in good condition-no obvious scratches or wear marks. Quite a bit of black carbon dust shook out of the router when I replaced the main bearing, probably as a result of my brush filing(?). The small bearing seems fine.

This router (router 2) is usable but seems like it should work better. Any advice about what to look for?

[pat warner]

If the thing runs rough with no cutter, collet or casting (base), then I'd overhaul it or scrap it.
Vibration is your enemy in Routerdom.

[Michael Mayo]

You say the small bearing looks fine but if you replaced one bearing why not replace them both? That way you have no reason to question the bearings being your source of vibration. I learned long ago when working in the auto biz as a technician that if I am going in I may as well replace everything while I am in there no matter if it needs it or not as I am already in there. I would replace all the bearings in the router to be sure they are all in a known condition.

[david brum]

That's a good idea. It's a 6001Z bearing on that end. I have some a work. I'll try it tonight.

Does anybody know if replacing the brushes with new ones could help? My router isn't that old and the brushes don't seem to have much wear, but I don't know much about universal motors, either. Are there other factors that could be causing vibration?

[Thomas Hotchkin]

David

I've got two Dewalt DW618 routers. One runs perfectly smoothly with no vibration(router 1). The other vibrates a bit, so it sound different and doesn't cut as smoothly(router 2). I just replaced the main bearing on router 2, hoping that it would take care of the problem. It runs slightly better, but not as well as router 1. I can't stand it!

Here's what I know: Router 2 has what appear to be good condition brushes. I did file the shine off of the surfaces in an early attempt to get it to work better. The armature appears to be in good condition-no obvious scratches or wear marks. Quite a bit of black carbon dust shook out of the router when I replaced the main bearing, probably as a result of my brush filing(?). The small bearing seems fine.

This router (router 2) is usable but seems like it should work better. Any advice about what to look for?

If you filed the armature it might not be round any longer, at 22K rpm any small change could be a new vibration. Tom

[Bob Wingard]

I think he filed the brushes to rid of the shine ... not the arbor ... might be wrong, but that's the way I read it.

[Michael Mayo]

The only thing I can think of would be the bearings given you have not changed anything else. Messing with the brushes I would think would not have any effect on whether you have excessive vibration as they are very soft carbon and spring mounted so they should not be the source of any noticeable vibration. Bearings and balance is where I would guess the problems lies. I would not think you have a significant balance problem unless the router was out of balance straight from the factory so the only other thing would be bearings. I would replace the smaller bearing and any other bearings that may be in the router and re-test. If you still have excessive vibration I would contact the manufacturer and see if they might possibly send you a replacement as a router as previously stated cannot have any appreciable vibration or else you will end up with unsatisfactory cuts in the stock.

Also check the bearing bores or seats where they mount into the router. I am not familiar with your router but the bearings should not have any lateral play when installed or else you will have vibration issues.

[david brum]

Thanks guys. I definitely didn't file the armature, just the brushes. It didn't help. I do wonder if it's possible to smooth the armature, though.

I also replaced both bearings and didn't notice much difference in performance. The big bearing is a surprisingly loose fit in the aluminum housing, loose enough for the outside of the bearing to rotate with the router running. Maybe I should try some loctite?

I should also mention that this router gets hotter than the other, good one.

[Thomas Hotchkin]

David
Sorry maybe I misread your first post about filing. If your router's armature has a metal cooling fan, you can check tracking of each blade. Some rough handling at manufacture could have bent one or two blades. Not much you can do with plastic fan blades. Also if your removed bearing fit correctly your new bearing may be under size. We ran into this a lot with imported bearings. The armature's commutator can be turned by a good motor shop, and then rebalanced. Could be less expense to buy a new router. I ran into the same problem with my router getting hot after bearing replacement, my bearing supplier sold me the wrong bearings for the motor rpm, had to get a different bearing grease. Tom

[david brum]

If your router's armature has a metal cooling fan, you can check tracking of each blade

Unfortunately, they're plastic.


Also if your removed bearing fit correctly your new bearing may be under size.

I bought a US built bearing, supposedly "Premium Motor Grade". The original bearing was a pretty loose fit as well, although this one is looser. Grrrr.

I hate to give up on this router, since it is so versatile. Maybe I will just look a getting a new motor body and hope for the best.

[johnny means]

I've got several 618s around the shop and have had similar bearing problems. I had tgem repaired by my local dewalt service center only to have the same sports of problems resurface. They have all now ben relegated t to single purpose set ups and will be scrapped if they ever die. I assume that there must be some thing about the design that affects bearing life. It's shame because it is my favorite router design. anyway my point is, in hindsight I wish I had not repaired them and just replaced them with something else. I would have never regretted a shiny new Festool.

[david brum]

I suppose you're right, Johnny. I hate to just give up on a tool that seems like it should work, especially since these routers weren't cheap. I don't think there's anything more I can do, though. I think I'll follow your lead and use them until they die, then replace them with something European. Too bad there isn't an upgraded motor body to put into all the bases that I have.

[Thomas Hotchkin]

David
Ereplacements $60.00 http://www.ereplacementparts.com/armature-assy-p-71537.html Tom

[david brum]

Thanks, Thomas. The only issue is that I'm not really sure if it's the armature, bearings, alignment or a combination. Argh.

[Bob Wingard]

LOCTITE does have a "gap-filling" bearing retaining compound ... #645 if I remember correctly. It will glue that outer race in place, and can be loosened with moderate heat.

[Thomas Hotchkin]

David
It can be a never ending fight. My 3HP PC router is doing the same as your Dewalt, it's 24 years old and limited parts. Good luck on your project, keep posting maybe someone here will have your needed answer. Tom