Pigbearman

Hey everybody,

First off, new to the forum. Also, mostly new to the RC world (about 3-4 months). So thanks for this website and all the support you guys give.

So my car is a converted Exceed Madspeed Drift King turned on-road racer. A while ago I installed a Hobbyking Xcar motor/esc combo, not knowing that the QC on these are just awful. Well, last week the ESC died, so I went ahead and purchased a Castle Sidewinder 3 with a 6900kv motor. From what I've read these are mostly used for off road buggys/short course trucks, but can be used just fine for on road applications.

So, I installed it and ran it. After probably 5 minutes of doing some light driving along with high-speed passes (the thing is crazy quick), the car stops moving. The servo still steers but the motor does nothing. Shut it off, took the body off and felt the motor. Not a problem, maybe 100°. Feel the ESC, and it's laser hot, at least 160, maybe more. My gearing is somewhat aggressive at 35pinion 69 spur, but I always thought that would cause more issues with the motor temps instead of the ESC.

Motor: Castle 1406 6900kv
ESC: Sidewinder 3
Pinion: 35T 48P
Spur: 69T 48P
Battery: Turnigy 2S 25C 6000mAH

So my question is, what's the best solution to the hot ESC problem? I've read that this is an issue with Castle ESC's. The ESC looks like it has holes to mount a fan, but I can't seem to find any fan online that is made for the ESC. I've also read that adding an external BEC could help, but I'd rather keep the solution simple.

Any help is greatly appreciated,
Thanks

GSPOT

iTrader: (62)

raise gearing so its slower, larger discharge battery...ie 65c
fan mounted to car to blow over speed controller, capacitor to power and ground for help for the power discharge.

latest updates to controller?

no binding in car, no extensive speed runs.......

ThePanda

iTrader: (68)

Do be aware that the sidewinder esc's do run hotter than others. Did you temp it with a temp gun/sensor, cuz past like 130, anything will feel "very hot" to he human touch. 160 is a bit to hot though if that is what it is.

VenturaDC

iTrader: (32)

Just delt with this at the track a few weeks ago, a young kid was running a touring car with the exact same sidewinder and gearing and continued to have similar issues all day, at the end of the day with we ended up with a 18/80 gearing combo. The car was actually faster with the low gearing as it let the low torque hi rpm motor wind out and do it's thing. Mounting a fan will not be enough to keep the esc cool at that gearing.

Geezatec

Why the ratio Pinion to Spur? 2 to1!!!! Motor working to hard. Brushless run smaller pinion. Drop to 18 to 25. You find quicker of line. Temp out the ESC pinion too high like 35 which you have.

Pigbearman

A friend of mine is going to bring in a 20T pinion for me tomorrow so I can give that a try, I just don't understand why with an aggressive gearing, the ESC would overheat, not the motor.

ThePanda

iTrader: (68)

The motor is drawing moore amperage than the esc can provide. The motor might be geared fine, just its too powerful for the esc with current gearing
If that makes sense.

GSPOT

iTrader: (62)

high speed, less torque

low speed, high torque
(2 ways of looking at electric motors)


if high resistance, esc or motor it will heat up

VenturaDC

iTrader: (32)

Because that is a seriously high wattage motor, so making it dig that low just to get the car moving it's asking a lot of amps from the esc, when for instance with a 17.5motor no matter how much gearing you throw at it it's not gonna pull nearly as many amps on the esc so esc stays cooler but motor is working hard so it over heats

beamcat

As 6900KV you will need to run around 8:1 to 9:1 gear ratio for touring car. With your car's 2.35 internal gear ratio, you will need around 18-20T pinion with your 69T spur. And as touring car put lot of loading on ESC and motor, it is good idea to add fan to ESC and motor, and not sure if your sidewinder3 ESC can handle this motor in a touring.......

Pigbearman

So I ordered a new chassis, Spec-R S1. Comes with an 84T spur gear. I'll be buying a 20-25T pinion today, and I also have a fan coming soon. Hopefully the Sidewinder 3 can cool off and handle it, otherwise I'll have to grab a Mamba.

VenturaDC

iTrader: (32)

Start low on the pinion and work your way up watching the temps, the sidewinder can handle it just fine as long as you're geared properly

ThePanda

iTrader: (68)

Look into the sidewinder fan case. It comes stock with the sct edition sidewinder, but can be used with the other versions too.

Pigbearman

You know, I noticed something a couple days ago that makes me think I either have:
Sidewinder 3 with different case on
or
some other esc with sidewinder stickers on.

Every image I have seen of the sidewinder 3 shows it with smooth sides, nothing to clamp a fan on to. BUT, my ESC actually has little areas on the side where a fan would snap on. I asked Castle about it but no response from them yet. I ordered a fan made for I think the mamba monster 2, should be here today so I'll see if I can get that to work.

asc6000

iTrader: (15)

learn to gear it properly first, get a full range of pinions
here is a great article on gearing
http://www.teamassociated.com/pdf/ca...ear_ratios.pdf
none of that other stuff matters if it isn't geared properly