Quote:
Originally Posted by aittam
Hello,
i'm still having problems gearing the Mamba Max 5700kv for the DB01.
2 weeks ago (midday, 32°C) with 17pinion and 91spur gear:
- after 7minutes of racing the motor was 75°C and the esc 65°C
- after 25minutes of racing the motor was 91°C and the esc 75°C.
Yesterday night (10pm, 23°C):
- with 16pinion and 91spur gear:
after 10minutes of racing the motor was 64°C and the esc 52°C;
after 20minutes of racing the motor was 81°C and the esc 62°C.
- with 15pinion and 91spur gear:
after 10minutes of racing the motor was 80°C and the esc 51°C;
after 20minutes of racing the motor was 81°C and the esc 53°C.
I cannot make the motor run cooler than this.
Do you have any idea what else can i try? Should i try a bigger pinion? Or a smaller one?
If i try a smaller pinion i might run it too undergeared.
I'm worried that even if I stay with the 15 or 16 pinion and go racing on a hot day, i will get much higher temps.
Thanks.
Mattia.
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Mattia,
The closest you are getting to the breaking point of to motor is 91°C after 25min of constant running (93°C is the breaking point).
Most racers do not run their cars on an offroad track for 20+ min straight. That much constant run-time will heat up any motor; even if the gearing is good.
It is best to keep your practice runs at 10-15min and then take your car off to cool down for a bit.
You may be able to improve the cooling by cutting the vents on the Durga body and/or switching to the carbon reinforced chassis with the heatsink plate and the hop-up motor mount. I have done both and the cooling improved quite a bit.
The last possible thing I can think of is to upgrade to a high end ceramic nitride bearing kit (like the one from BOCA). The Durga will gain a slight edge in top speed and will have less friction to work against. It would make only a minor impact on heat at best, but it is nice to have.
Hope this helps.
Dan