Awesome stuff guys, sounds like a project.
So I'm watching videos on how to apply this arctic silver thermal compound, and it seems this might be a little tricky with all these fets... Any advice on how to safely apply arctic to the fets.
First, clean the tops of the FETS with denatured alcohol to remove any flux, grease, etc. from the manufacturing process and handling. Do the same to the bottom of the heatsink and if its a really smooth surface, rough it up a bit with 220 grit sandpaper to give the epoxy something to bite into then clean with alcohol again.
To apply the epoxy, mix up a small batch, a little goes a long way, and use something about the size of a wooden matchstick to apply a small dab to the top of each FET. Keep in mind that its going to spread out a lot when you press the heatsink down on top so just a small dab in the center is enough. While there is a certain amount of conductance to the Arctic Silver it also can be capacitive so any that spills over onto the circuitry could cause problems use the smallest amount that will do the job. Once the Heatsink is glued on and the epxoy sets, its never coming off without taking part or all of the FET with it so you get one shot at it.
The epoxy does kick off fairly quickly so do the ESCs one at a time and mix a new batch for each one. If you have a bad ESC laying around try epoxying the original alloy heatsink to it to get a feel for how much to use and how quickly it sets.
I cut the heatsink so that the edges line up with the edges of the FETs with no overhang, not strictly necessary but its easy enough to do when you have a mini-mill in the garage. With epoxy on all the FETs just line up the heatsink on top and push down lightly to spread the epoxy out then leave it alone for at least 30 minutes to let the Arctic Silver dry. After that I slide a large piece of heatshrink over the whole thing then give it a good blast from the heatgun. Once it cools, use an exacto knife to trim the heatshrink around the base of the heatsink and you're done.
Ken
