Hello everyone. It took me while but I finally have installed a new motor from R4F and my Gem seem to runs well 
(It is scary fast too)
Now, the controller overheats when going uphill so I will be installing two of those heat sinks with a switch to activate a computer fan.
The big reason the controller overheats is because you have over size tires. An inch or two reduction in diameter can make a world of difference.
Hi Guys, I finally found some time to work on my GEM. Mock-up of the controller cooling assembly. I will install on the T2 controller on the car with thermal paste shortly.
Did you put the fan on only one half because that’s the half with the forward drive FETs?
I’ve opened a blown T1 and the FETs run the full length of the case on both sides but I didn’t map out which were forward and which were reverse.
Ya, I am wrestling with this too. I suppose he could take it for a hill climb and see if there is part of the backside that is hotter that the rest and direct his air flow there. Having the temp switch on a different part of the heat sink might be an issue too. Bring an alligator/jump wire along with you for the test run so you can easily wire it full-on if you need to.
Depending on the rpm speed of that fan it may be noisier flat mounted on the fins like this. Do a bench test as is, then lift the fan off the surface and see if it is quieter. Sometimes all you need is a couple washer/spacers. Another idea would be to lift one edge of the fan about an inch(more?) and direct air over the entire finned area.
Thank you for the input. I just bench tested the fan and it makes no noise when on. My logic was that the temp sensor would always be on the warmer side of the controller and as it would trigger at 115 degrees it should keep the fan going and the entire controller temp to stay under 120/130 ish. If it doesn’t work I will change the design to have 2 smaller fans to cover more surface of the heat sink.
