[deacs]

Hi All,
have just joined up and a quick intro, I have in the past been a framer but now only do my own stuff. I am now just a DIY'er really and looking to fit my kitchen out. Looking forward to learning new skills and hopefully helping out where I can.

I recently purchased a used makita 3612c router off ebay (I know probably not the best idea) that was described as working, turns out it does work (to a fashion) in that it starts up and spins really slowly with a fair bit of brush sparking you can see from the top vent. It doesn't spin up all that fast (the variable dial does however change the speed), my biggest concern is when I let go of the trigger and the motor slows down, the motor seems to catch and jolt the router to a stop which suggests either the motor or some other part is binding on something.

Could this be a bearing problem or is it more serious than that? I've checked to see if there any play on the chuck (by wiggling it side to side) at it seems minimal.

I've also checked the brushes and they don't seem all that worn, what could be causing all the sparking? does anyone know if there is a service manual for the 3612c? There seems to be no problems in fing user manuals but nothing in the service manual dept.

I haven't opened the router up yet as if it's beyond economic repair I'll try and get my money back, the ideal is that it's something easily remedied.

cheers
Deacs

 

[sreilly]

Welcome to the forum. I'm not familiar with this router but is it possible it was damaged by shipping? Maybe a claim is warranted....

 

[Biagio]

Hi Deacs, a few of us this side of Greenwich have that model, and can attest to it being a workhorse. Check that the spindlelocking mechanism is not the problem. If not, chances are it has been abused - if you can, get your money back.
The sparking may be due to a worn/damaged commutator - no idea what that would cost to repair.

 

[roxanne562001]

Welcome to the forum. I would contact ebay they are usually very helpful getting you a refund / return from the seller just don't wait too long to file something with them.

 

[jw2170]

Welcome to the forum.

Apart from my Tritons, The 3612C is my goto router....
It may be an issue with the speed control?

Keep in mind, if you want to go down that route, you only have a limited time to claim back from Ebay, if you paid by PayPal....

 

[jw2170]

PS.. You can get the manual from here.

Makita - Library

Makita Power Tools. The preferred brand of power tool to the trade

www.makita.co.nz

 

[old55]

Welcome to the forum.

 

[sunnybob]

Remove the brushes and then spin it by hand. If it catches or rumbles then send it back straight away.
If it runs smooth and runs on look at the commutator (the segmented bit that the brushes run over). If its corroded or jagged you can GENTLY sand it smooth. Then buy new brushes anyway.

 

[deacs]

Thanks All for the advice and welcome, much appreciated.

It deffo wasn't damaged in transit so no option for a claim but yep paid by paypal but again given the seller didn't say good working condition I may struggle but we'll see.
I'll inspect the spindle locking mech and commutator and see if it is still usable, fingers crossed. The router certainly is very used and I would suspect abused.

thanks
Deacs

 

[Biagio]

You can find the parts diagram and list at mtmc.co.uk

 

[deacs]

mtmc.co.uk

Cheers Chap, yup I found that one and have saved it but had wondered if they did a service manual (a bit like a workshop manual for cars and bikes).

What would I be looking for in the spindle locking mech that might be a prob? It's spins freely enough and seems to tighten and loosen well enough.

I see you have the SAFA flag on your profile, so when you say you're over in Greenwich I take it you're over here in Blighty now? I'm originally from Cape Town but been over here for 27 years now crikey - thats makes me a whole lot older than I want to be

cheers
Deacs

 

[deacs]

Remove the brushes and then spin it by hand. If it catches or rumbles then send it back straight away.
If it runs smooth and runs on look at the commutator (the segmented bit that the brushes run over). If its corroded or jagged you can GENTLY sand it smooth. Then buy new brushes anyway.

Thanks for the advice there SunnyBob, I've removed the brushes and spun the spindle up but hand as you suggest and it seems pretty smooth and runs on for sec or 2. If I was super critical I could say there's a slight rumble but tbh it just sounds like the bearing spinning and nothing sinister.

I guess I'll pull it apart and inspect the commutator and take a look at the speed control as JW2170 mentions.

thanks again
Deacs

 

[deacs]

Thought I'd post a video of it running up and then slowing down - it may just be the power of the motor as it slows down but my cheapy 1/4" doesn't kick like this.

router sparking and slow down kick

 

[Biagio]

Hi Deacs,
By east of Greenwich I meant this side of the Atlantic- most of the guys are in North America, and are used to other brands. No, happily sweating in Jhb, watching you guys freeze, but the east coast has just been hit by Tropical Storm Eloise.
Your problem does not sound like the spindle-lock. I gather sometimes a weakened spring lets the locking pin vibrate into the hole in the spindle, causing the sudden lockup you describe.
Try what Sunnybob suggested. I have had little traction from smoothing commutators, but your mileage may vary. There is another site that has the "workshop manual" for other Makita routers, but surprisingly has only a one-pager for this model. Makitapro.ru.
From memory, a former member called Stick486 posted a whole lot of stuff (conveniently available in pdf) on how to test motors, and general router troubleshooting - well worth the search (things have been re-organised due to a platform upgrade, otherwise I would have found it for you).

 

[deacs]

Ahh I get you, yup we've just had a light dusting of snow here in Oxford but nothing worth going out for

Thanks for the advice appreciate it, I've downloaded the pdfs so will run through the tests I took a look at the Russian site but couldn't see anything relating to router maintenance but the exploded diag should suffice.

thanks ahain
Deacs

 

[Biagio]

Just a thought: if you know your way around the electrics, or know someone who does, it is possible to bypass the speed controller. If the motor then behaves normally (other than speed control), you have a culprit.
Just to be sure, I went and fired up mine - it does have a little kick on stopping, but not to the exent yours shows in the video. My brand new Makita has the same little kick, some of my others wind down more slowly. There may be an EU requirement as to how quickly an electric tool must come to a stop - health and safety.

 

[deacs]

Cheers, yeah I think the kick was like a brake system (although since cleaning it doesn't seem to catch like before) thanks for the advice.

I've cleaned up the commutator as it had a lot of carbon build up and was quite scratched, it looks a whole lot better now.
As I don't have new brushes I sanded the rough and sharp edges (where it seemed to be scratching the commutator. It's still sparking although maybe not as much as before (can anyone confirm if they have sparking on theirs and how much) interestingly the kick has now gone after cleaning the router completely when it was apart.

I'm not sure the thing is spinning up to full speed as 23k rpm should seem a lot faster (this may be the switch as you say Biagio and JW2170 advised), I don't suppose some kind person would post up a video of their 3612c spinning up to full rpm would they?

 

[Biagio]

Deacs, I could try a video (no time right now), but not sure how you would gauge the rpm? I do not have a suitable tachometer, not sure how reliable it is, doing it by the noise?

 

[Biagio]

You might be better off by-passing the speed controller, at least you would hear what max rpm sounds like on your machine.

 

[deacs]

Cheers Matey, it just sounds very slow and the motor should whine a lot more than mine at full rpm (it could still be the commutator is faulty / worn?!)

I'm considering just sending it back for a refund so if I start removing bits I might end up being in contravention of ebay rules ?!