Options for Overheating (Smoking!) Motors

[.bg.]

I've got a pretty modified CC01 that has seen use mostly as a basher. Recently, I've begun to crawl a bit with it and it smokes every motor that goes into it within the first few minutes.

My guess is that the CC01 is the worst case scenario for a motor when attempting to crawl due to the fact that the motor is almost completely enclosed with zero airflow and that the truck is geared extremely high even with the smallest pinion available.

I'm sure it also doesn't help that I'm now running 3S on it, however, I was smoking them when crawling on 2S as well.

So far my failures have been:
Traxxas 21T 14.4v 550 Motor- (really thought this would've held up to crawling, as my others lasted forever when used for bashing- also has an integrated fan)

RC4WD 45T Motor- (Smoked <5m)
RC4WD 55T Motor- (Smoked <5m)

I have an Integy 70T motor that I'm about to try an see if I have any better luck.

Do I have any other options? Whether it's a motor or something else?

I realize that I probably should get a GRU and then run the 70T or something, but I'm trying to keep as much wheel speed as possible in the process.

I'm considering purchasing a motor heatsink with fans on it- is it possible that this could cool the motor enough to keep it from burning up?

I may try a slightly more expensive motor (such as the HH Torquemaster Sport), but I hate the thought of putting anything more expensive than a $25 motor in a truck that is mostly a basher/mudrunner.

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To summarize, to keep my motors from heating up and smoking while crawling:

Is my only real option to get a GRU and a high turn motor?
(losing most of my wheel speed in the process?)

Or will a motor cooler or simply a "better" motor alleviate the issue as well?

[badBKO]

Is the esc getting hot also? When you take the motor out, does everything spin freely?

[.bg.]

Originally Posted by badBKO

Is the esc getting hot also? When you take the motor out, does everything spin freely?

I've got a BRXL in there- it heats up a bit, but I haven't seen it too hot to touch yet. No drivetrain drag... it's a moderately heavy rig (~6lbs), but nothing too crazy.

I've also tried running without the holmes/hold dragbrake to see if this would help keep temps down- I couldn't really tell a difference, but could the hold/db contribute to high temps as well?

[Dabandit1]

55t pushed my 6 1/2 pounder around effortlessly try a integy lathe motor.


Stupid question but you broke your motors in first right...fresh brushes low speed and drag brake dont mix
Is it a shafty?,what tranny?,what spur?,wheelweights?,what tires/wheels?

[.bg.]

Originally Posted by Dabandit1

55t pushed my 6 1/2 pounder around effortlessly try a integy lathe motor.


Stupid question but you broke your motors in first right...fresh brushes low speed and drag brake dont mix
Is it a shafty?,what tranny?,what spur?,wheelweights?,what tires/wheels?

It's a CC01 Chassis:





It's got 3oz's of wheel weights and some rear chassis weight. Running the smallest pinion you can run on the CC01 (16 tooth).

I break in the motors - 5 minutes at 4.5v in water.

I'm almost positive this wouldn't be happening in another chassis such as the SCX10 for two reasons:
1. The gear ratio is still very high even with the 16tooth pinion and
2. The motor gets no airflow. Plastic surrounds almost the entire motor in the cc01 chassis.

Again, everything works fine for bashing and when I'm "crawling" in water like above it never smokes up, but that probably has a lot to do with me repeatedly submerging the truck.

[Dabandit1]

Hmmm got me ratio does sound high though

[TexasSP]

How long did you have the traxxas motor in there before failure?

It could just be those RC4WD motors, they seem to be failure prone. Try the integy and see what happens.

The 3s should not be an issue, it is definitely something else. How high do you have the drag break set? That could be another issue.

[.bg.]

Originally Posted by TexasSP

How long did you have the traxxas motor in there before failure?

It could just be those RC4WD motors, they seem to be failure prone. Try the integy and see what happens.

The 3s should not be an issue, it is definitely something else. How high do you have the drag break set? That could be another issue.

I had run the traxxas motor for about an hour of "bashing" over the past couple weeks. It was still running fine until I attempted to do some slow rock crawling this weekend. I did have the drag brake set to 100% on this motor. Still getting accustomed to the BRXL and didn't realize how strong this would be.

I turned off the drag brake completely when running the RC4WD motors. Since they burnt up as well I figured it didn't make any difference...

but I didn't try the Traxxas motor on a smaller db setting and now that I think of it the Traxxas lasted about 15 minutes of crawling with 100% db before going out, whereas the RC4WD ones burnt up in <5 minutes with no db.

Think I may have better luck with another traxxas installed with a motor heat sink and fan and a lower db setting? I did love the torque and wheel speed I got from it...

I'll try the 70t Integy tonight and see how the truck fares.

[SACCO]

The integy will be much better. I run a 65t in mine.

[JohnRobHolmes]

If you are getting any heat on my ESC I would suggest you have some binding in your drivetrain. The only time I have ever heard of my ESCs getting more than lukewarm in a crawler is in a super with no heatsink.

Take off the motor pinion and see how easy the rig will roll. It should spin nice and freely and keep rolling if you push it.

[EeePee]

Originally Posted by JohnRobHolmes

The only time I have ever heard of my ESCs getting more than lukewarm in a crawler is in a super with no heatsink.

Just to add to this, in my Losi Comp Crawler with a 35 turn motor on 3S and not using an external BEC while using a HiTec 7950TH and 5245 servo it did get warm. Sometimes almost hot, but not enough heat to cause concern by me. But that is one tough load for an ESC...

[.bg.]

Originally Posted by JohnRobHolmes

If you are getting any heat on my ESC I would suggest you have some binding in your drivetrain. The only time I have ever heard of my ESCs getting more than lukewarm in a crawler is in a super with no heatsink.

Take off the motor pinion and see how easy the rig will roll. It should spin nice and freely and keep rolling if you push it.

I'll check it again tonight. Seems fine though, truck is as fast as ever! I've done a bit of research today on those that have attempted to crawl on a CC01... seems that many are recommending a 55T with a 4:1/3:1 GRU to slow it down.

As is, the CC01 on 70T with smallest pinion is outrunning my stock SCX10 on a 12 turn motor.

I do love the wheelspeed of it, but realize there has to be give and take here... I just want has little give/take as possible.

[JohnRobHolmes]

Originally Posted by EeePee

Just to add to this, in my Losi Comp Crawler with a 35 turn motor on 3S and not using an external BEC while using a HiTec 7950TH and 5245 servo it did get warm. Sometimes almost hot, but not enough heat to cause concern by me. But that is one tough load for an ESC...

Losi's excluded, they aren't normal

Point being the CC01 shouldn't be stressing the ESC at all with even a 27t on 3s.

[.bg.]

Would running these motors in reverse cause them to heat up and smoke out?

I didn't get to take the truck out last night, but I did mess with it a bit. I noticed that the wheels were spinning faster in reverse than in forward. So I flipped the outputs on the BRXL so that it is now going faster in forward than reverse. I'm guessing I've been running the motors in reverse since I got the BRXL. I don't think these are advance timing motors, so it shouldn't matter right?

Not sure why they were reversed, however, as my connections are aligned from the battery to the esc to the motor and I did calibrate the esc. hrmm..

[JohnRobHolmes]

The traxxas motor is timed. Im not so sure about the sealed can motors from rc4wd.

Which direction is the pinion rotating for forwards locomotion?

[Erin]

Could the 5 min water breakin be causing this?

[JohnRobHolmes]

If the bearings are rusting, yes.

[killswitch]

The CC01 is geared too high out of the box. You are really better off running a 65-80 turn motor or some type of gear reduction. I run a 65t on the smallest pinion that fits and I still have wheel speed when I need it with my CC01. Back in the days of the OG CC01, I would constantly smoke motors when trying to crawl it. That chassis was never meant to be a crawler... it was supposed to be a scale beater with a solid rear axle and a cheapo tamiya motor.

[JohnRobHolmes]

I wouldn't think that he would smoke 55t motors on 3s in there, although I haven't tried those rc4wd motors. I always broke parts even with a 55t integy motor before the motors would smoke.

[.bg.]

Think I made some headway before a catastrophe.

The rig rolled smoothly and easily as I pushed it around on the floor. However, I noticed something weird with the driveshaft while crawling the truck straight up my garage wall.

It seems that during my last rebuild of the rear diff I had left out a bearing behind on the back side of the diff shaft. During regular bashing this wasn't an issue- it also wasn't an issue when I was testing for any driveline binding, however, if I applied serious torque to the truck (while crawling) the driveshaft was shifting out of place. Seems like this would definitely introduce driveline drag.

The fact that it was only happening under heavy load made it difficult to track down, but you guys definitely called that one!

I also installed the Integy 70t and ensured the that the motor was now spinning faster in forward than reverse and took the truck out. It was significantly better, although not completely fixed.

I was able to crawl for about 15minutes before the motor was too hot to touch. It never smoked, but it seems like it could be on the way if I crawled for another 15 minutes. The esc was still cool to touch and I wasn't using HH or drag brake.

I'm pretty sure that a motor heat sink and fan may take care of this issue and have placed an order for one.

--

Now the bad news. Took the truck back to swap in the Traxxas motor again to see how it would work out, but saw that my new Integy 5s battery had arrived in the mail. I balanced charged it and installed it into my rally car with the BRXL, but immediately upon plugging the battery in, the esc went up in a huge puff of smoke!

I immediately unplugged it, but the damage was done. I attempted to plug in a 2s and immediately more smoke. No idea what happened here, I'll send John an e-mail later today.