Copper flashing = heat strap = no-cut ESC cooling solution?

I realize the simple cooling solution is to cut 2 big rectangular holes in my enclosure, install proper heatsink plates for my ESCs. I held 2 150x93x10mm heatsinks in my hand I’d bought for this purpose, can’t in good conscience add 2 pounds of flab to an already heavy build, nor chop up a nice water-tight enclosure. There has to be a lighter/easier way.

I like what Lacroix did, gluing a thin aluminum plate to the inside of the CF enclosure, but my enclosure is plastic, not as good a conductor of heat, thicker, the plate weighs nearly as much as my heatsink, requires a tube of expensive thermal epoxy to implement.

While investigating fanless CPU/GPU cooling solutions I came across a novel heat-pipe setup that uses flexible tubing to circulate some CFC-like substance that changes from gas to liquid and back while circulating, works great transferring heat to a remote heatsink. Too expensive, but I love the idea of moving heat outside the enclosure with heat pipes.

I also found heat straps, made from stacked thin copper strips, anchored at each end to either the heat source or heat sink. I think this has value here.

I’m going to try stacking ~5 sheets of very thin copper flashing, probably 100mm/4in wide, under each ESC, (securing the case + copper + ESC stack with screws that penetrate the bottom of the case,) then bend the copper up the side walls of the enclosure, over the lip, where they will be fanned out a bit for more surface area. My goal is only to conduct some of the head through copper sheet, out to where it can more easily be dissipated.

I’m considering doing this not only for the ESCs, but also for the 4x Lipo packs I’m using as a “race” pack… They will get hot under half-charge, and this might help me drain 'em a bit deeper w/o heat issues. (I chose plastic-encased ROAR-approved packs, which was dumb, so will probably skip this step.)

I’m assembling the board this week, will post photos and some logs if this method of stealth cooling pans-out.

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Epoxy and/or butyl rope solves all these problems

On one of my boards I conduct some of the heat away to an external heatsink, through the ESC mounting bolts (not copper) that go through the enclosure. It does seem to work okay-ish if you’re not pulling huge currents. The external heatsink does get hot. It’s a much more muted phenomenon than a directly mounted heatsink though.

You can’t see but there is a thin air gap between the aluminum plate and the enclosure wall.

I love the butyl rope = strip caulk, use it all over the place. I cut a big hole for an Infinity Cheapskate heatsink for the Flux Motion build, was hoping to avoid that for this one. I used exactly that to seal the heatsink to the enclosure. This enclosure is a crazy mix of materials (styrofoam + fiberglass + epoxy + a molded outer layer of plastic!) and I’m going to have a hard enough time drilling clean holes, let alone sawing it cleanly. I copped out (pun somewhat intended) on this idea, ordered a pair of very nice (15W/mk) 2mm silicone heat transfer pads instead. If simply being pressed against the enclosure w/ this as a transfer layer works, I’m home free. I’ve never tried a Ubox/Spintend ESC before, nor anything beyond 12S with a VESC, nor motors this huge… I’ve no idea if I’m going to need serious cooling or not, will at least try the thermal pads before implementing this. Sorry to post then bail on my own idea so quickly :slight_smile: