Question about router carbon brushes

Hey there everyone… have been absent on the forum for a while basically because it has been a long and cold winter, and I’m just now getting back out to the workshop, putting me waaaayyy behind.

Prior to shutting down the winter, we had replaced the entire Makita router, because three times within the space of two-three weeks, we had to replace the carbon brushes.

Ok, so I just started carving again last week. I have completed two pieces relatively small, both less than 300 x 200 mm. And I believe that after the replacement of the Makita, I only ran it one or two times to complete two projects.

So that being said… i’ve run this router now a total of maybe five times. And that is a push… short runs, no all day projects.

Yesterday I started up the router, it sounded so nice and quiet… as routers go. This evening, it is clanking…
:::shrugging::: I already have to change the brushes…?

After a lot of research… this just doesn’t seem right…
Am I missing something… what do I need to be looking at… obviously if I’ve changed out the router, it must be my setup… just not really sure what would cause the brushes to be affective.
As for speeds and feeds I use the guides between Sienci and PreciseBits. I don’t ever exceed recommendations…

So what should I look at next? Well I was going to upload the video to let you hear the noise in case I was wrong, but I it just now refuses to come on… so I believe I’m correct.
If anyone can let me know what I need to troubleshoot, I’d be happy to hear… thanks.

with the router off, is there noise, when you jog the does the machine move fluidly?
any odors coming from the router body?
clanging and shuddering, needless to say not good and now that it does not start uh oh!
sounds like more money to me!

Changing the brushes a couple of times, I would suspect the bearings. Router OFF, see if there is any play by the collet end.

Hey Andy…no, no noise when router is off…only when u hit the power button and for a moment, the noise was only at lower speed.

Now of course brushes changed, no noise.

No odor at all.

Yes, fluid movement all around

So we thought about that to. With the router off…there is no wobble at the collet and bit.

I mean if we have replaced the router itself, and we are experiencing the same problem in so few cuts…what else can it be?

Once my router started making a bad noise and slowing down so I shut it off thinking that I needed to replace my router. A couple hours later I thought about the brushes and took them out. One of them had a bent spring which I straightened out by hand. It has run great ever since.

My experience doesn’t sound like it is much help for you but it’s all I have. Not sure if you’ve removed the brushes in the second router yet but if not I would check them out and see if one is bent or anything.

Michael, well it is definitely the brushes hands down…i need to find out why now two routers are needing frequent brush changes? This new router has maybe five carves. That seems fairly extreme for a new router to already need brushes.

@chapklc I can’t speak to the original brushes in a Makita router. However, some of the non-OEM brushes being sold on online stores like Amazon are reported as being terrible. I have only replaced the brushes on my Makita once in many hundreds of hours. You may want to contact a Makita authorized repair location and speak to them. The local one here is excellent.

here some words that helped me understand the noisy result i got when replacing the brushes on my porter cable 691.

How Are Carbon Brushes Maintained?

There are several ways to check for issues and to be sure your carbon brush — and your motor — are working properly.

One of the first things to look at is carbon brush stability. Check the clearance between brush holders and the brush to ensure it is stable and slides properly. It’s also important to check the distance between the brush holder and commutator slip ring to ensure the brush holder is adjusted correctly and at the proper angle.

It is important to also check for signs of commutator wear and for the presence of copper dust. Dust leads to high brush wear, machine pollution, grooving of commutators/slip rings and brush side gulling. The best way to prevent this is with regular motor cleaning to ensure air filters provide clean air to the motor.

My holders were not correct and the commutator was worn , however the router is quite old. I adjusted the holders .

this excerpt above is from

How It Works – Carbon Brush Operation - Renown Electric.

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Grant… Right!?! Hundreds of hours…thats what my brain is struggling with. We are adjusting power and positions today…I changed out the brushes last night… so hopefully this will be the solution…