High temp problems - Hot Bodies D8

[wallot]

25 min bashing at grass field = high temps

get it on the track and you will se that the temps will go much lower

[jnev]

Originally Posted by zeropointbug

First of all, I am running the same motor, except finned version on 6s lipo in a Revo 3.3, and after a 30 min main the motor temp was 130F, verified by two different temp guns (cuz I didn't really believe it). The Revo is quite a bit heavier, but I also have better airflow, and a finned case...

I don't really know what else you could do?

BTW, is that tape on the motor to hold the Neu end bell cover on?

The new Neu motors don't have an endbell attached by screws, so the dust cover has no way of holding itself on. The electric tape is working surprising well, and doesn't look too terrible I must say.

Originally Posted by rootar

alot of us run that motor in buggies and revos and the temps are always amazingly low, id change your start power to high, and punch control on 30-50 %, also if you dont have holes it your body its time to open it up... also gearing up 1-2 teeth would help your motor temp. its sounds like its running at too high an rpm too much....


gear it up and raise the start power to high (low is for 2wds, med is for really light cars, and high is for all the 1/8ths and MTs because they need a good bit more power to intially move, so raising the start power makes it less lilely to cog and makes it easier on the esc....

I just changed the setting so hopefully they'll help out. I am about to cut some holes in the body and check the solder connections as well. Bearings throughout the car are all smooth. So you're saying there may not be enough load on the motor for it to run efficiently? I am at 18/48 and don't have a 19t pinion - only a 20t. With the 20t I'll be geared for exactly 40mph. You think that will be ok? I bought this motor for the exact reasons I hear from many others... it runs very cool. Hopefully its simply a matter of changing a couple small things.

Originally Posted by zeropointbug

My Revo was geared for 35mph when it temped 130F (80F day), but it was mostly a steady 1/4 throttle, and one long straight.

But I have found that the temps don't change much even gearing it up to 45+mph on the track.

Do you have any 6s lipo packs? If so, try that and gear for same speed, and try a 4s lipo as well... then see what the temps are. IIRC, when I used to run 7s2p A123 pack, I tried using 5s2p pack, and geared up, it just didn't have the power, and it ran hotter as well.

I just sold my last 6s pack actually a week or two ago. Bad timing... I may try selling this motor and trying out a Neu 1512/1.5y which is 1900KV or a Tekin 1900KV motor both of which I'd assume would run cooler.

Originally Posted by wallot

25 min bashing at grass field = high temps

get it on the track and you will se that the temps will go much lower

I definitely can understand that, although the grass was pretty short. Hopefully I can back out to the track soon, and see how it does.



Thanks for the help guys. Cross your fingers and hope for the best.

[othello]

>Even with the motor installed, I can push the car by hand and it rolls freely.

That seems not right. There should be a noticeable drag when a Neu 1512 is connected to the drivetrain. Remove the pinion and turn the shaft by hand. If it turns freely like a feigao/Lehner your rotor might be (partialy) demagnetised or the shaft is not connected properly to the shaft. If so the motor will compensate the loss in torque by taking far more amps (leading to higher temps of your components) when accelerating but you might also experience a higher revving motor -> more top speed. This might also lead to cogging while starting up as amp draw is much higher then usualy.

Around 4000mAh and a runtime of 25 mins calculates to an average amp draw of only 9.6A (with 18.5V -> 177W average). This shouldn't lead to such high temps. You did not mention outside temperatures btw.

Your tires don't seem to be able to provide super high grip (Amps while accelerating shouldn't be very high). I would expect much tire slip leading to high motor rpms to keep your car moving at a decent speed. This also heats up a motor.

Running on a grass field is challenging for electric components. I can empty my batteries faster on this type of surface as drag is higher and more power is needed -> leading to higher temps of all components.

I would expect your motor to be the root of your higher temps.

[E-Revonut]

Originally Posted by wallot

25 min bashing at grass field = high temps

get it on the track and you will se that the temps will go much lower

This is most likely your problem! Grass is alot more drag than most realize. Esspecially with a buggy, you have smaller tires and not a lot of ground clearence, not only do the smaller tires not roll through the grass easy but your plowing grass with the entire chassis and suspension. Try running on dirt or ashpalt and see check your temps

[zeropointbug]

Yeah, grass field, why didn't I realize that would be the cause of it...

If I run in a large grass football field (off season, not cut), WOT,the motor temps at 165F, that's in a Revo, so a buggy will have a much harder time getting through the grass, would take more power for sure.