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BrianG · 05:45 PM

Wow, that sucks. Too bad you can't stuff the smoke back in! :)

Seriously, I always worry about that happening to mine. That's why I get an ESC that will handle at least 50% more current than the motor requires. I took the shrink off my BK 12020 and noticed the FETs are stacked with a layer of PCB in between. Each layer had heatsink grease, but the layers were not closely mated, so the heat on the lowest level is the highest and is the most at risk of thermaling. The little heatsink they do have is only on the very top level.

I think some of the problem with these ESCs (BKs in particular) is the fact they make them as small as possible so the heat is too concentrated, even with a heatsink. I wouldn't mind a bigger unit if they would increase the reliability. Or, even a 2-part ESC; one part for the "brains" and current sensing which would keep the processor and other related components cooler, and another part for the high current output FETs that use larger TO-220 (tab style) devices individually heatsinked so the heat is properly dissipated and replacement is much easier for the normal person. Plus, a 2-part design would isolate the "smoking" part.

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BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	05.21.2006, 05:43 PM Wow, that sucks. Too bad you can't stuff the smoke back in! :) Seriously, I always worry about that happening to mine. That's why I get an ESC that will handle at least 50% more current than the motor requires. I took the shrink off my BK 12020 and noticed the FETs are stacked with a layer of PCB in between. Each layer had heatsink grease, but the layers were not closely mated, so the heat on the lowest level is the highest and is the most at risk of thermaling. The little heatsink they do have is only on the very top level. I think some of the problem with these ESCs (BKs in particular) is the fact they make them as small as possible so the heat is too concentrated, even with a heatsink. I wouldn't mind a bigger unit if they would increase the reliability. Or, even a 2-part ESC; one part for the "brains" and current sensing which would keep the processor and other related components cooler, and another part for the high current output FETs that use larger TO-220 (tab style) devices individually heatsinked so the heat is properly dissipated and replacement is much easier for the normal person. Plus, a 2-part design would isolate the "smoking" part. Last edited by BrianG; 05.21.2006 at 05:45 PM.