Brushed motor burnt/toast?

[Shinjari]

Alright so I have a Holmes torquemaster 45t expert. Was in my 1/6 Willies jeep, specs are scx10 axles with xr-10 mod & scx10 tranny 87/17 gearing, BRXL, Hitec 7950 steering servo on TSS Stockers wrapped in 1.9 TSL XLs. Ran it at least every other weekend for an hour or so on 3s for a good 6 months with no issues. Decided to go with a 35t in it, and put the 45t in my Hilux.

Hilux has similar specs, scx10 axles, tranny, 87/16t gearing brxl, 7954sh servo, on tango downs wrapped in Pitbull growlers. However when I took it out for its debut run, about 10 minutes in there was a burning smell and even a faint sign of smoke when i stopped the rig.

The motor was not too hot, as I was able to put my finger on it for at least 5-10 seconds with it barely being 'warm' in my opinion. Adjusted the gear mesh and tried to run it a bit and still same scenario....burnt smell and now a buzzy/clicking noise.

Got home, took it apart to check brush lengths and comm condition....however as mechanically talented as I am (have rebuilt 1:1 motorcycle/car motors)....I dont really know what I should be looking for

Brushes are approximately 10mm still, when I remove the brushes the armature spins smoothly, except now I hear that clicking I mentioned.

Pics (crappy ones) are below, only thing I 'think' is wrong is the washer that goes on the end bell side of the arm looks chipped/flat spot (in the 7 o-clock position of the pic). Maybe the brushes are toast? they are a little discolored. Cleaned it up with compressed air to get any dirt out, and put it back together and it runs smoothly, but with the clicky and now faint burnt smell still.

Oh, and motor has never seen mud/water if thats important


Anyone got any ideas? New brushes? Comm cut? I'm trying to learn how to fix it myself, worst case I can have it rebuilt by the pros at HH.

Thanks!

[WHITE-TRASH]

It's called maintenance and you should learn how to do it. Or just mail the motor back to HH for rebuild. All that's needed is the comm needs to be cut and the brushes cleaned up or replaced.

[Shinjari]

Originally Posted by WHITE-TRASH

It's called maintenance and you should learn how to do it. Or just mail the motor back to HH for rebuild. All that's needed is the comm needs to be cut and the brushes cleaned up or replaced.

Well I'd love to learn! So if it needs a comm cut...then I need a lathe ....and brushes are easy to replace and break in. So maybe I do need to send them in for simplicity

Is that all that caused it to become noisy and burny smelling? It's the sign that it needs some new parts? Thanks

[WHITE-TRASH]

As crusty as that comm looks I'd say there is something causing drag in the system. Whether it's gearing (not likely since you listed your gearing and it's fine) bad bearings somewhere in the drivetrain etc.

[Howler]

In the first pic of the brushes, that one hardly looks seeded. The com doesn't look too bad. A bit dark but certainly not burnt. Make sure that your brush hoods are aligned and the bushings keep getting oiled. If your hoods are off, the brushes will not get full contact, and you'll loose power. Also, it helps to gently file down(bevel) the leading edge of the brush. This will also help aid in seeding, as well as prevent chipping to the brushes.

Best bet may be to try a new set of brushes. Break in at 2amps for 2 min, then 5 for another 2 min. Also recommend a cooling fan blade on the armature to aid in cooling as well as give a nice load to the motor.

[TEDROCKZ]

Originally Posted by Howler

seeded.

Oh my...

OP, if you saw smoke and it had a burned smell you most likely shorted a wind, it happens. Still worth sending in. A replacement armature and rebuild is still cheaper than a new motor.

[Trubble]

Originally Posted by TEDROCKZ

OP, if you saw smoke and it had a burned smell you most likely shorted a wind, it happens.

Agreed. That's what I thought might have happened when he showed the endbell off, and two of the windings looked hazy and dusty. Could've been just dust/grit that was on the windings, or could have been that the lacquer had overheated/burnt.

Might want to just consider a new armature anyway. As said they're not heinously expensive. Plus, it's not unheard of for a short like that to fail to reveal itself in a resistance test, but then show up as the motor warms up again.

Them brushes also look kinda suspect to me. If the brush hoods were far enough off to produce those kinds of wear patterns, then I'd wonder if the 'ticking' noise was the leading edge of a brush knocking into the gaps of the comm as they came by.

I have an old Speedworks Pole Position motor that required a similar amount of work. I'm sure most would've just chucked a 30 year old not-really-anything-special motor, but I liked it enough to ask that the effort be put into it. (shrug) Sorry Eddie, I was willing to let go of the Fireballs, but this one means somethin' to me.

Guess the OP is going to have to decide how much he likes that motor. On something like Integy, Venom, or even a Tekin machine wound, I might not be willing to go that far with it, just pick up something new. But on a Holmes Expert, I'd likely ask my rebuilder to save it. Gonna require some TLC, though. Your call.

[Shinjari]

Well all seems to be good info. I dont think theres much drag in the driveline as without the motor there it rolls relatively smoothly, i mean not brand new smooth, but it moves freely.

The brush in the first pic has a poor angle so its hard to sell if it seated properly but it looks similar to the other brush. It is a expert motor, thus was broken in by the pros at HH.

Ultimately it sounds like I need to send it in. Which is ok, like mentioned it's cheaper than buying an entire motor (hopefully lol). Going to send it in along with my other motors to get serviced. Thanks for the advice/opinions they were much appreciated.