***brushless Motor Overheat***
 

anyone got motor overheating problems on the HPI E-FIRESTORM ? mine I cant get it run cool I tried smaller pinions , smaller tires , other motors , other batteries... it still go over 190f to 200f more...

What motor do you have? Gearing, batteries? There re tons of people willing to help you, but we just need a little bit more info.

he's using this motor...http://cgi.ebay.com/4300KV-Brushless...3286.m20.l1116

Are you able to put your fingers on it for more than a few seconds?..

did you try gearing up?

I tried this 4300kv motor the link aqwut have posted and I tried Mamba Max 5700kv both overheat ...

actually I run the 4300kv motor and 18t pinion on 87t spur. ( tried 17t pinion and still overheat )

my MAMBA MAX settings :

punch control = 50%

motor timing = lowest

start power = low

drag brake = disabled

default throttle curve

default breake curve

cut-off = 6.3v

check for driveline drag

Have you tried putting it all in the speed calculator ad seeing what speed your geared for?

http://www.scriptasylum.com/rc_speed/_top_speed.html

Id go with Brushlessboy16 on the gearing, I dont have a Firestorm but it kinda looks like a 2wd pede type tranny. Its probably spinng way too fast, no time to wind out. Id pop in around a 25t pinion if you have an 87t spur and check that.

for a 3500 kv
http://i274.photobucket.com/albums/j...peed_chart.jpg

going to try larger pinion soon ..

brushlessboy16 : check for driveline drag ?

sorry I dont understand...

check to see if anything is binding

hmm my front wheels friction sound good ... and my rear wheels too spin like new ... im going to try 23t pinion soon after my pack got charged.. and let you know guys :yes:

hmm I tried 84t spur gear and 18t & 19t pinion and now it finaly run cool... 145 to 160f ... outside its 20 celsius ...

yay, keep gearing it up untill temps start going back up :D

20t or a 21 tooth would lower temps even more

brushlessboy16 : why 84t spur gear give me more lower temps ? ( 84T spur = less acceleration and more top end .. ( 87t spur give more acceleration and less top speed .. ) ? stock e-firestorm are 87t spur 19t pinion and all peoples always use this gearing with brushless setup ...

The motor was spinning way out of its efficiency range probably. Too numerically high of a final drive ratio, and it doesn't put enough load on the motor. Still haven't figured out why brushless motors like a certain amount of load to run cool...

There's a general rule of thumb to not overgear, but also not to undergear a motor.

ok thanks...

guys take a look on this motor can it is useless to put a heatsink on this ?

http://img33.picoodle.com/data/img33...2m_73de019.jpg

its a giant heat sink itself, maybe screw a fan in the vanes ? <ducks from thrown vegetables>

yeah true..

whats about if I use a heatsink + fan combo on this already integrated huge heatsink does it can work just fine or ... ?

I run my 2s 7.4v lipo pack at 6.3v cut-off does it got a big difference in runtime from 6.0v and 6.3v cut-off if yes how much ?

The runtime difference won't be more than a few seconds, and is definitely not worth the risk. If possible, it wouldn't hurt to run the cutoff as high as 6.6v. If the battery is any good it won't have any problem staying above this limit.

ok thanks for your reply. and whats about a 3500kv brushless motor and 4300kv does I can notice about 5min more runtime with the the 3500kv instead of the 4300kv ?

Geared for the same speed they should theoretically have the same runtime. There are a number of other factors which determine runtime, including driving style, battery choice, etc.

hmm for now im geared 18t pinion 84t spur and I get 30mph on the 4370kv motor with the 3500kv for get the same speed ( 30mph ) I should use 84t spur and 22t pinion so the runtime will be almost the same ?

The 22t should give approximately the same top speed. Which motors are you comparing? That will make a difference. For example, the VXL 3500 uses a larger rotor than the Castle motors, and so runtime is affected accordingly.

for now I use this one :

http://cgi.ebay.com/4300KV-9T-Brushl...QQcmdZViewItem

--->

MAX AMPS FOR THIS MOTOR IS : 40AMPS

do larger rotor give more or less runtime ?

In this case the VXL 3500 should theoretically give less runtime due to its larger rotor. It doesn't work like this all the time though, because you have to factor in the efficiency of the motor given a certain load.

if the esc and battery stay cool and only the motor get damn hot whats its can be ?

undergeared?

Yeah sounds undergeared to me too.

ok ... and whats about the symptoms of overgeared ?

They are Fairly close. Ussually the esc will be cooler then motor on undergeared. Esc gets hot on over geared. Always exceptions to rules though.

I run 19t pinion 87t spur dont think it is under or overgeared on 2s 7.4v ... my e-firestorm 2wd stadium truck complete with battery/body into it is about 5lbs... esc are like about 120 to 130f and motor 180 to 195f ... battery are cooler ...

why dont you start from the beginning of your thread and reread

I know but I always got the same problems ...

Have you tried a 25t pinion ? according to your thread the highest you went was 19, I run 30/74 on a similar setup and it only gets hot after long runs because its overgeared

I tried 23t pinion it is the biggest I have in my hands and still same...

well if you use a 23T pinion and your 84t spur and the motor is still burning hot you probably cooked it and demag'ed it. http://www.rc-monster.com/forum/showthread.php?t=14381

hmm I opened it and still magnet so very fine on the inside of the motor can ...