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Old 11-17-2014, 11:57 AM
  #814  
pompebled
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Originally Posted by intenserapture
Can you explain more about sanding the fets? Is sanding them ok?
I assume this is because they are cheap build and not fitting correctly?
Cheers
Hi Intense,

I take a piece of flat hardwood, the width of the Fet board and glue a piece of 120 grid sand paper onto it using double sided tape.
I clamp the wood in the vice and move the fets over the sandpaper, this way I have a better control over how much I take off and I can avoid clipping the capacitors.

Once all Fets are in one plane, I use a vacuum cleaner to remove the dust and refit the watercooler.
I usually omit the heatconductive mat (which insulates), but use a smear of heat conductive paste.
Take care not to cause a short on the connectors when you reposition the watercooler by putting a fresh piece of shrinkwrap around the ESC.

@ SRT 10: My math is correct, I always multiply the no load rpm by 0,8 to account for slippage and losses in the drivetrain.

I agree that an ESC will not fail when only working them at 20 to 30%, but that's not what I said; when only a fraction of the Fets have physical contact with the cooler, a small load like 20 -30A may let out the magic smoke.
All the Mystery ESC's I have treated, still work after a decade of running them in competition.

Waterproofing them is a good idea, because they really don't like getting wet when working... (poof).

Regards, Jan.