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Sep 26, 2017, 12:45 AM
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LowFlyingKiwi's Avatar
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DIY Brushed motor heat sink/cooling. Any tips/tricks?

Hello people : - )

I am getting into the "hot motor" zone in my flying practice.
This is causing a bit of anxiety as I don't really want to thrash my motors. (Yet. )

I saw a random picture somewhere, I forget sorry, where someone had wrapped copper wire
about the motor case.
Looks heavy.
But is increasing the heat absorbing mass and increasing the surface area. : - )

Any other "non fancy alloy clip on fin things" that actually work?

Am considering some thick copper wire wrap, with an air gap and soldered at each end.
Can you open up the vents in the motor to get some air flow?

In the future I would like to go three phase brushless but I need an adapter gadget which I do not have.
( the DC motor output from 4in1 to the ESC, adapter. They exist but can you still get them?)

Any tips would be appreciated.

I am getting a solid five min of hovering out of one flight and this heats up the motor some...

Thanks in advance!


PS will post some pics if I do attack the motor with copper wire. : - )
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Sep 26, 2017, 02:29 PM
Back in the day, (and see post history!) used to fly FP a lot.
On my main go to heli (FJ45), the main motor was easy to replace with a BL equivalent: the tail motor not so much. However, after trying many ideas for a BL tail (best was a drive motor from a PC DVD) eventually settled on a bulk buy of tail brushed motors from China.
Did try a lot of experiments to improve the life of these motors. Heat sinks, ducted air etc. However, in the end found that the motors would last roughly 50 flights regardless - so found the most reliable 'solution' was a paper sticker on my helis which I marked after every flight.
After 40, the motors were retired. Before this, pulled quite a few apart (after failure) and found that the cause was invariably wear to the copper strip 'brush' assembly.

Of course, YMMV! - and I know many others here swore by the elegant ribbed heatsinks they'd fitted to their motors (both main and tail). But all but one of the few that reported on the results afterwards, still found the redline was at about 50 or so flights.

Go brushless if you can! - had over 1k flights on one BL motor before I jumped ship to the CP world

Cheers - John
Last edited by OldOz; Sep 26, 2017 at 02:35 PM.
Sep 26, 2017, 06:42 PM
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LowFlyingKiwi's Avatar
Thread OP
Ah, right. Darn. So the normal DC motors are "disposable". Drat.

What I need is the Brushed to brushless signal adapter thingy....

and they seem to be in very low demand. any clues as to where one can purchase them?

Thanks all the same!

Sep 27, 2017, 08:45 AM
Registered User
Steve_'s Avatar
Here are a few links:

Here is a link to a thread on the subject. It's old, but the information should be somewhat useful.


Brushed motors and model helicopters don't mix well because of the high current demand.

You best route is to buy a helicopter with one brushless motor, using a belt or shaft to drive the tail,
but it won't do you any good if you crash right away.

There are lots of good helicopter simulators:

The neXt simulator also has a demo:

There are more, and hopefully folks will chime in.
Last edited by Steve_; Sep 27, 2017 at 09:10 AM.
Jul 13, 2019, 12:23 AM
Registered User

copper wire

Any heat transference is a good thing. I have still got my first V912 brushed heli with a copper wire spring heat sink I made when I found out as a newbe these motors don't last long.
Basic idea is 2.0mm copper wire formed around a tube or dowel smaller than the motor. In my case 20mm dowel for the 25mm motor.
Wind it over the motor and space it so the vent holes are not blocked.
Full contact is the key and ventilation, I cut out the top frame on mine above the motor.
I have no hard data but would say they last at least 30 percent longer.
Tail motors are fiddily little buggers but may be worth the same.
Bottom line is it's all fun and learning is all part of this amazing hobby

V912/ V950/ V922/ MCPX/ Master CP BL/ V915 BL FBL/ FX071BL FBL

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