HALVE your motor temperatures with this 5 minute mod!!!!

[PH001]

Hey all, thought I'd share this one with you as the results were so impressive. Have a HPI Truggy Flux running an 17T pinion so was looking to reduce motor temps a tad. The scream motor is a 4072 can size (i.e. 40mm dia) and there are not many convection heatsinks out there that fit (didn't want active cooling as the BEC on the std ESC is pretty weedy tbh).

 

I have got a small clip on aluminium extruded heatsink but it only takes off about 5'C at best. I then had the idea of baseplate cooling the motor with a 42mm wide copper strip. The copper is 0.5mm thick and wraps around the motor under the heatsink. The other end is clamped between the base plate and the plastic side trim.

 

I was astounded to see motor temps drop from 76'C to 41'C (8'C amb)!!! The baseplate does get a little warm but that's not really an issue. Got to be the best value for money mod out there and took literally 5 minutes to install....

 

Edited October 16, 2018 by PH001

[Desolation91]

Where did you buy the stuff from?? I noticed mine was hot the other day wires and motor. 

[PH001]

We stock the copper foil at work. Seems fairly tricky to buy from the likes of Ebay / Amazon unfortunately. Can’t see us paying more than £20 a meter for it.

[Bajadre]

yeah great little mod there buddy always wonder about using copper strips or thermal paste like on pcs etc I know maplins used to do the copper strips but there gone now I think most diy stores should do copper tape though worth chancing it

Edited October 14, 2018 by Bajadre

[PH001]

Yeh, could try copper tape but a lot of the stuff is really thin so i’m not sure you’d get enough thermal conductivity. Worth a go though. I think its so effective as you have a huge surface area on the 3mm aluminium baseplate that has loads of airflow over it.

[Fly In My Soup]

Don't use copper tape...its glue backed

 

Nice find ph001! 

 

 

[Nitroholic]

Basically...when you think about it ....it's obvious.

 

Well..these things are when someone else does it

 

Heatsinks, like that GPM one, will not have good contact with the motor casing. They are not made to fit a specific item and variations in case size will reduce the contact. Heatsinks only work when they have good contact with the motor. Otherwise...heat won;t transfer to the finned heatsink, and the heatsink can't radiate the heat.

 

The copper strip takes up the slack. Not only is it soft material ( especially this thin ) so it will deform to fit the space, but it has excellent thermal conductivity. Thus ensuring the heatsink has maximum contact with the motor case. Thermal paste should do the same job, but if you ever have to take the heatsink off....you will have a cleanup job before refitting. I also wonder whether it would pick up dirt and just get messy as it's not fully hardening. A thin strip of copper sheet? Just give it a wipe and put it back.

 

Now....wrapping it round and clipping it to the chassis plate....well...that is turning the WHOLE CHASSIS into a heatsink. One that is potentially in contact with muddy ground, damp grass...all things that will shed heat. It is also one part of the car that is always in airflow. I reckon thats the biggest benefit to this idea.

 

0.5mm copper sheet is sold by a lot of model stockists for model making..and it's on E-Bay. probably going to cost you £10 for a piece big enough to wrap around...but you will get enough to do a couple of motors in the sizes. Just make a paper template and check that size before you buy!

 

Thanks for sharing @PH001

[PH001]

5 minutes ago, Nitroholic said:

Now....wrapping it round and clipping it to the chassis plate....well...that is turning the WHOLE CHASSIS into a heatsink. One that is potentially in contact with muddy ground, damp grass...all things that will shed heat. It is also one part of the car that is always in airflow. I reckon thats the biggest benefit to this idea.

 

Yes, that's what is key here and why it reduces the motor temps so dramatically. It was one of those ideas that hit me at 2am in the morning then kept me awake for the next 3 hours ?

[Virdi]

Link to the heat sink please?

[PH001]

Any 36mm (540 motor size) heatsink should work as long as you can flex it out slightly to go around the motor. This is the one I got but only because I thought the 40mm in the description was the diameter not the length ?... https://www.amazon.co.uk/gp/product/B075LFRPPD/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

 

If you are going to go for something similar then you might as well get something cheaper UK based. You could probably secure the copper foil around the motor with tyraps to be honest if you cut a slot in the foil to locate them. I don't think the heatsink does a great deal (especially an ill-fitting one) - it's the conduction path into the chassis that makes the big difference.

 

Edited October 16, 2018 by PH001

[capri-boy]

A nice cheap mod - good to see how effective it is.  I had some custom mounts made for one of my RC's a few years back - hugely over engineered but do act as a great heat sink itself - much better than the two piece mounts.  I shall be trying this myself on the next build - i'm generally not a fan of fans - too often they're used to lower temps caused by other things - over gearing / binding in drivetrain etc - though do like to keep temps under control - and with UK weather extremes a good set up in the winter will run too hot in the warmer months. 

[0013]

For the ones who can't buy copper foil you can always use any kind of thermal pad or computer thermal paste. Will reduce a lot the thermal resistance between the motor and the heatsink.

 

I am surprised that no one tried to make a thermal connection between the motor and the metalic chassi yet. That would be extreme cooling

[capri-boy]

10 hours ago, 0013 said:

For the ones who can't buy copper foil you can always use any kind of thermal pad or computer thermal paste. Will reduce a lot the thermal resistance between the motor and the heatsink.

 

I am surprised that no one tried to make a thermal connection between the motor and the metalic chassi yet. That would be extreme cooling

 

A good one piece motor mount transfers some heat, I've often toyed with trying pc thermal paste in the past to help further.  Clamp type motor mounts, like the HPI vorza make a fair amount of contact with a motor, though I guess the quality of the materials used affects how well it transfers heat.

[PH001]

Aluminium is pretty good tbh, but copper is better.

[Fly In My Soup]

+1 thermal paste is not for me

 

I'm gonna try this too when I get time to hunt supplies