Ailing Makita SCMS needs help

[gordons]

Once again, I come to you for assistance.

My Makita LS1013 SCMS worked fine for the just short of its first year warranty period. Then all of a sudden, when you fire it up, it rattles like there's loose parts in it and it runs slowly and has no torque.

This happened very suddenly while cutting up some regular 2X4's - no warnings, no smoke, no grinding, nothing other than what's described above.

I took it in to the agents who claim to have torn it down and checked it and there were no problems found. Brought it home, same problem. Took it back to agents, they plugged it in and it seemed to run fine. Back home - no go.

I have a separate 20A circuit breaker on my board just for my tools. Eliminated possible extension cord problems by plugging saw directly into outlet - no luck. Tried another separate 15A outlet - no go there either. Took it over to the neighbor's - still sounds like a bucket of bolts with no guts.

My BT3100, Ryobi and Craftsman routers, Rigid CMS, Belt Sander and ALL other tools and accessories run fine off both these circuits. It's just the Mak that ails badly.

Before I make a third trip to the Agent, or try and get hold of a Makita rep, can anyone suggest something that I may try, or look for, or see what I don't?

Any help is much appreciated. Thanks.

[jbrain]

The motor brushes might be a possibility as they are a wear item. Should be in owners manual on how to check them. Hope this helps.

[SARGE..g-47]

My first thought would have been the circuit.. you eliminated that. My second would be brushes as mentioned.. you still have to go there. If they are OK kindly post any info you find on the fix as I am certainly curious as too the problem beyond those two....

[sweensdv]

For your sake I hope it is something as simple as the brushes. If that is what it turns out to be then never ever take this or any other tool back to that repair shop. Brushes should have been, if not the first then, one of the first things he/she should have checked.

[LCHIEN]

First thing that went thru my mind... rattling + slow rotation + no torque = Loose arbor bolt.

But that seems rather obvious for both the user and repair shop.

[herb fellows]

Am I mistaken, or did you say it ran fine at the store? I was going to say loose arbor bolt also, but if it ran ok in the store...?

what about breaking out the camcorder and taking a short film of what it is doing at home. Bring that to the store and let them figure it out from there, maybe that will help.

[gordons]

Thanks for all the suggestions.

Yes, it did seem to run OK at the repair center. I was there and witnessed it.

The arbor bolt is as secure as it will ever be. When the motor runs, it just sounds wimpy and both the RPM and torque are way down. It will cut, but doesn't do that very well on anything above a 1X3 soft white wood.

I checked the brushes again today and they have a good length on them and the pigtails seem secure as do the fittings. Just out of curiosity, is it possible that one of the brushes has a crack in it that could cause this loss of power, much like a cracked distributor cap on a car from "the good old days"?

As a last check, I also shook the saw's power cord around like a lasso while running the saw in the hopes that if there was a break in that wire, it would manifest itself. No luck there I'm afraid.

[gordons]

I took a short video of the saw in motion. It appears to run faster in the video than it actually is. You may have to turn up the sound a bit to get a better effect. Here's the link:

http://www.youtube.com/watch?v=xgCOyPuKlLg

[RAFlorida]

Been following this thread.

Is there any way you can check the voltage at the plug for the saw? I suspect a voltage drop.



Reread your post about trying at the neighbors and still the same problem. That may well eliminate voltage drop from the power source.

[SARGE..g-47]

Very strange.. you said that the saw doesn't come to full power so I suppose that eliminates the blade slipping on the arbor bolt when making contact with the wood to be cut. I would most definitely call Makita Tech and see if they have en-countered this before. I know a number of local trim men that for years have used both Makita and Hitachi local and I have never heard the complaint... Again..

[gordons]

Just to keep you updated on the saw mystery. I have been in contact with Makita tech in Buford, GA. Sent them the video link and they then asked me to send another one of the saw cutting some lumber. This I did. Their opinion is that it might be a speed control or an armature problem. The guy I was dealing with is away on vacation this week, so I guess I'll have to wait till he returns before I know what the next step will be.

[big tim]

I once had a problem with a gas fireplace fan, after running for a while there'd be some squeeling and the squirrel cage would slow down.
When I took the motor apart it turned out that the armature and commutator were loose on the shaft. Once it got warmer the armature and commutator would then start to slip. This could be your problem.

Tim