Need help - hot brushd motor

[mark in wi]

I have a Reedy MVP 24* stock motor I want to run in my gold pan. Any time I to use it the temp goes from cold to HOT in about 2-3 minutes. I took it out of the car and with no load it is warm in 2 minutes and getting very warm by 3 minutes. I can still hold it as long as I don't touch the heat sink by the brushes. I assume (I know) that this isn't normal and was wondering if anyone had any ideas I can try to get it to run cooler??? The motor was given to me and I was told that was new except for being preped to run.
Thanks
Mark

[minreg]

Assume you have put a drop or two of oil on each bushing.
It is rebuildable so you could have a look inside.
Anything else unusual you notice?

[mark in wi]

I added some oil and tried again with the same results. Opened it up and nothing looks unusual. It does seem to spark at the brushes more than the ohers I have. This might not be a big differance since I never trued my coms on the others so it might be normal. It almost feels like the brakes are on when I let off except with the other motors I don't get the same feeling. I even tried to adjust the ESC and it didn't help.

Any other ideas??

Thanks again
Mark

[urban hype]

Gearing or gear mesh? If you over gear it will get way hot. When I was racing stock my motors would be so hot that that you could hear it sizzle after the run.

[dldiaz]

I have had several brushed motors with the same 'problems' - they get real hot and they have a ton of drag (like the brakes are on).

** I have not always been able to 'fix' them.**

Sometimes a thorough rebuild helps - take everything apart, even pop the bushings out of the endbell and the canister, clean everything real good, skim the commutator (if needed), new brushes (if needed).

Then re-install eveything very carefully - be sure to fully seat the bushings, align the brush hoods, and shim the armature so the brushes are centered on the comm.

It is also pretty cheap to upgrade to ball-bearings (instead of bushings),
the motor bearings are available for a few bucks online.

In my experience, you may still have a motor that runs hot after all this.
I don't know if that means the commutator is beginning to fail (short circuit),
or if there is some other inherent flaw in the motor???

[Lonestar]

be careful when you upgrade bushings to bearings as you need a bearing puller/pusher for the can side to not ruin them at installation time, which would make things worse than a misaligned bushing.

If the comm diameter is lower than 6.8mm it is done, bin it or shelf it.

Otherwise it still runs hot after deep maintenance (properly installed bearings, new brushes but only if you true the comm, brush hood realignement) and with proper gearing / transmission / mesh, then there's a problem in the winds, bin it or shelf it.

Paul

[mark in wi]

Gearing isn't the problem. It gets hot when holding it in my hand.

I'll have to talk to the guy I got it from and see what he did to "prep" it. If he has no ideas I'll have to start looking for another to use.

Thanks again
Mark

[Stumpy]

Mark,

Essentially the Reedy MVP is a race motor.. It is designed to give maximum performance for a 5 minute race.. The result of that performance is heat, as you have found..

The MVP, or any 24* rebuildable stock motor for that matter is not designed to be used as a "basher" motor..

24* rebuildable stock motors are very high maintenance.. The brushes usually have a very high silver content which causes the excessive wear on the commutator.. To keep the motor in good condition, the comutator should be re-trued after every race meeting (approx 4 x 5min races), and to get the maximum performance from it, re-trued after every 5 minute race.. The brushes should also be replaced each time the comm is re-trued, especially if the brushes are discoloured (i.e. blue in colour)

If you plan to just have a run around the street etc (bashing) then a mild modified motor of around 20 - 27 turns may be more suitable to your needs..

Mark..

[minreg]

This motor was supposed to have some pretty aggressive magnets. Not sure since my newest motor is probably a P2K.
Lots of good ideas here. Maybe the best is to see the guy who gave it to ya.
If you remove the springs and spin the comm by the shaft... Does it turn spin freely, easily?

One of the posts suggest his motor would sizzle and that got me to wonder why you are touching the motor anyway. LOL.
Was there a performance issue while running in your car.
I wonder what "prepped to run" consists of. LOL.

Good luck, hope you get it worked out.

[mark in wi]

It is very hard to spin it by hand. I had it out of the car and in my hand to make sure there was no other reason the motor was getting warm. I will talk to the guy next time I see him. He did say it was a race motor so I might have to save it for that only.
I'll let you know what I find out.
Thanks again
Mark

[Justin33]

Could always check how the armature was shimmed if its too tight with not enough ay that can cause some binding and heat aswell

[mark in wi]

Well I talked to the guy who I got the motor from and he said it was ready to race but he doesn't think he used it to race. His only thought was maybe the brushes were not the best. But he thought the motor would get into the 180s for temps after a five minute race. I ran an unscientific test yesterday using a LiPo and a NiMh pack. I made one run with each pack with a fan and few hours between runs. This was done with no load on the motor and with it out side of the car, trying to be consistant. Using a LiPo (Gens ace 4000 30c) the temp was 179* and 186* f at the 5 & 6 minute marks. With the 6cell NiMh (Venom 2400) temps were 181* and 187* at 5 and 6 minutes. Well I guess the concern that I had the LIPo was causing the heat my have been wrong. I can't remember ever temping my motors so I'm not sure if this is high or normal for motor temps. All I remember is motors were hot and the battery packs would be to hot to hold after a race.

Any idea what a brushed motor temp should be after 5-6 minutes of run time?

Thanks again,
Mark

[Lonestar]

Mark

it's always the same thing. If you want performance, you will push your gear a lot harder than if you want reliability/longevity.

The MVP was a performance-oriented motor - it was a very good "stock" motor. The drawback of stock is that it had to fit into certain rules, and as a result the manufacturers were pushing the stuff to the limit, without thinking about such petty things as heat and the likes. It wasn't uncommon at big events bitd to run a stock motor only for a couple of runs and then bin it as it was toast.

What I'm trying to say is: despite its performance being poor (vs. "open class" motors, vintage or modern), this is a race motor that won't last long. A bad choice for bashing... and a hot one too. Very impractical in 2013, unless you REALLY want to use THIS VERY motor, I would actually buy something else

200degF is not uncommon, as long as you're willing to cut the comm and change brushes every run (which is what we did bitd)

Best,
Paul

[minreg]

I used a Racetech Motor Cooler. A little shammy like cover that went around the motor. Kept in my ice cooler soaking wet till the race then installed over motor. Worked great.

[Lonestar]

I used a Racetech Motor Cooler. A little shammy like cover that went around the motor. Kept in my ice cooler soaking wet till the race then installed over motor. Worked great.

perfect for bashing