Motor, ESC temperatures

[WildWildWilly]

Hi,
There are many overseas articles on motor and ESC temperatures. Just wondering how hot is normal for our tropical climate? My car (Traxxas Rustler) on Castle Sidewinder 5700 combo under 19/86 gearing seems "very" hot after a 3min run @ MSCP. Sorry, I dont have a temperature gun (so not quantifiable) but only the 2sec finger test avail.

Appreciate any input

[LittleGiant]

Hi,
There are many overseas articles on motor and ESC temperatures. Just wondering how hot is normal for our tropical climate? My car (Traxxas Rustler) on Castle Sidewinder 5700 combo under 19/86 gearing seems "very" hot after a 3min run @ MSCP. Sorry, I dont have a temperature gun (so not quantifiable) but only the 2sec finger test avail.

Appreciate any input

u didn't mention how many cells are you running the motor on.
U also didn't say if it is the esc or the motor that is over heating.

[WildWildWilly]

6cell NiMH. Both motor and Sidewinder ESC heatsink are hot. Mayb I will go find a temp gun soon.

[psychophant]

6cell NiMH. Both motor and Sidewinder ESC heatsink are hot. Mayb I will go find a temp gun soon.

under normal circumstances, motor/esc temp of less than 60degrees is OK. anything higher than that, u might want to consider adding fans to increase the cooling rate.

ways of lowering temperature:
1. using less powerful motor: 5700 on the sidewinder seems to be stretching it.
2. using more powerful ESC with higher AMP rate.
3. higher gear ratio: smaller pinion or bigger spur.
4. check for drive-train resistance / friction: the smoother it is, less load on the motor and esc.

its good to invest in a temp gun to regularly monitor your electronics. i've seen some of my mates' motor burning up to 100degrees and melting away all the chassis' plastic parts. not a very pleasant sight.

[LittleGiant]

ok, from my experience, 60A brushless for 1/10 cars simply doesn't cut it unless the cars are geared really slow or u are doing drifting. I run my 1/10 buggy on 2s lipo geared to around 55 - 60kmph (fast but not too fast) with a 6000kv 540S brushless motor and a 60A yeahracing brushless esc. The motor runs hot but not too hot (around 60C max with lid on without heatsink or fan. The esc has a heatsink with fan but it thermaled (80C) like 5 min into the run. There was near zero airflow in the chassis because I did not run any hold in the lid for ventilation. When I run it without the lid, the max temp was also like 63C for the esc and 53C for for the motor. Ok I didn't run it normally. I went full throttle, hard brake, turn around then full throttle hard brake again. I did this alot of times. So this probably explains y the motor/esc heats up so much. My buggy only weighs 1.58kg with batt and lid. And I did test my buggy setup with a watts up meter. The meter probably couldn't capture much higher spike current but the max current captured was 56A. It usually stays at 33A. These current values doesn't even meet the rated 60A of the esc and yet the esc is already overheating. I don't see how the esc can perform at 60A cont without any issue. The esc is probably overrated.


Anyway I believe that the esc/motor will be stressed more under race conditions.

So I really recommend at least a 100A rated esc for your 1/10 vehicles if you don't want heat problems. I've tried 80A esc on my buggy before and the esc was totally cool. Probably this means that you can run your 100A esc in a 1/10 vehicle without a heatsink. By far the coolest esc I've tried is the HW150A brushless esc. But it is really huge. The esc runs cool on my 4.7Kg truck on 4S lipo geared to around 40mph (60+kmph). Using a KB45 2300kv in it (these motors run really hot. Don't use them for racing. I'm sure they will fail by overheating).

Another point to note. I've noticed a lot of ESC failures are due to them being run at their highest rated cell count even when the current draw is theoretically much lower than the rated specs. Spikes do occur no matter how you wish for it not to be there so be safe. This means that if your esc is rated up to 3S lipo, run it at 2S to be safe unless u are using it on very light applications like in 1/18 vehicles.


Cutting holes in the shells will definitely help lower temps. And IMO, the mamba max is a very good esc for 1/10 vehicles. I have one.

[WildWildWilly]

Thanks for the replies. I am currently experimenting with (3). (4) seems ok at the moment. (1) and (2) is out at the moment as I dont want to spend too much $$$. Its still a very new ESC and motor. The reason I opted for 5700 and not 4600 is I only intend to migrate to 2s LiPo later in the year. 3s and I will have to perform some surgery on my car batt compartment; something I am unwilling to do.

under normal circumstances, motor/esc temp of less than 60degrees is OK. anything higher than that, u might want to consider adding fans to increase the cooling rate.

ways of lowering temperature:
1. using less powerful motor: 5700 on the sidewinder seems to be stretching it.
2. using more powerful ESC with higher AMP rate.
3. higher gear ratio: smaller pinion or bigger spur.
4. check for drive-train resistance / friction: the smoother it is, less load on the motor and esc.

its good to invest in a temp gun to regularly monitor your electronics. i've seen some of my mates' motor burning up to 100degrees and melting away all the chassis' plastic parts. not a very pleasant sight.