heat sink on motors?

[silverback4jack]

Curious on what everyones take is on the heat sinks that go onto motors with or without fans. Would there be any real benefit on a crawler based on clod axles, or mainly go fast trucks and cars.

[Szczerba]

I thought about them but then I figured that would be the first thing I get caught on the rocks. The big old school ones I have anyways. I dont think heat is an issue with the motors. I have thought about a heatsink on my servo. It does get hot.

[Reflection]

no need in it.

Back in the day,before we had so many option for motors,you'd see guys run them once in a while.Today,most guys run at higher voltage,which helps temps. We also have allot better motors to pick from like the hand wounds or pullers. Even at that,even running a regular ol' lathe motor with the right gear ratio,they stay cool enough on their own.

[silverback4jack]

Thanks for the quick response guys. I do have a buddy that has a slash and he is smoking motors with his 8cell pack. I know it's not a crawler but any ideas why? I'm pretty sure it's a 550 motor. My cousin said he had heard of people haveing this problem with 8 cell packs and to try a 650 motor? Do u guys think the heat sinks on something that gets run hard and fast could help prolong the life of the motor or just a gimmick and something else needs adjusting?

[clockworks]

If a motor overheats, it's pulling too much current. The usual cause is gearing. Try fitting a smaller pinion.

A heatsink can help to lower the temps (as long as air can circulate around it), but it should be the last resort after everything else has been checked.

I don't see how using a higher voltage will help with the temps. Surely higher voltage = higher current draw = more heat, if you use the extra power. If you drive the truck exactly the same, it won't make any difference. If you exploit the extra power, it'll run hotter.
The only way that I can see extra voltage helping is you may spend less time stalled out.

[Failedabortion]

doesn't it require less amperage the more voltage you throw at it?

I know I killed most of my stock slash motors with heat from long runs, a whole 5000 pack without cool down.

[clockworks]

Originally Posted by Failedabortion

doesn't it require less amperage the more voltage you throw at it?

I know I killed most of my stock slash motors with heat from long runs, a whole 5000 pack without cool down.

For the same performance/power from the motor, higher voltage would mean less amps. The watts would still be the same though (watts = amps x volts, and watts is power), so the waste heat from the motor would be very similar.

Every motor has a "sweet spot", where the maximum percentage of the power input is converted to useful work, and the minimum is wasted as heat. It's possible that some motors might run cooler with some loads at a higher voltage.

It's also possible that, at very low voltages, the current would be too high, causing the windings in the motor to get hot.

I'd say that, if a motor is designed to run on 6 cells, it's going to be at it's most efficient (run cooler) on 6 cells. Going to 8 cells will give you more potential power, but it'll run hotter if you exploit it.