Quote:
Originally Posted by MPaulHolmes
I think I'm going to do an aluminum plate instead of a heatsink. I can mill the edges of the plate so that it has extrusions with holes that can be bolted to any old heat sink if you want, or it may not be needed. I think that's a much cleaner and professional (a la curtis, et al) way of doing it. I'm thinking of 3/8" plate. It will also keep the dimensions to a reasonable level. Not everyone could fit a controller that is like 6 or 7 inches tall (counting the heat sink) inside their car! Ben had a terrible time getting version 1 in his car.
I think HaroldinCR is right. All the support will be coming from the base plate, so it wouldn't matter if the sides are thinner. They would be there to keep out the elements, so I bet 18 or 20 gauge would be fine, Hondo. I'll PM you with more exact dimensions.
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Paul this is my first post here, but I have been lurking for almost a month now and have read the entire thread.
In my opinion I think that using the heat sink as the base is a good idea as long as it is sizable enough, the sheet metal enclosure shown earlier looks good to me but the aluminum version would be better, just bolt it to the heat sink. as for the end caps a flap on both ends for EMI reduction, even with generous cut outs for your bus bars will be nearly as effective as a full metal end.
now the details; make the end flap a little longer and bend back into the cover 1/4" and then down, so that it is inset the 1/4" . now after the controller is assembled, and the cover is bolted on, dip the ends just over the 1/4' in depth in a good potting compound.
this will give you good EMI control , good cooling and seal the unit from contamination. and it is relatively easy to make.
If you want the cover easily removable another option would be to skip the flap and instead use an aluminum end plate with an L at the bottom for mounting to the heat sink. again, pot the ends, but this time apply some Vaseline to the inside of the cover where the potting compound will be. the cover will then be removable.
because of the bending concerns mentioned in an earlier post, this second method with the removable cover, may actually be the easier version.
A little side note, I am also starting on my own DIY controller but in the very beginning stages, and yes it will be open source if I am successful with it. more on that later.
I wish you the best with this, and I am impressed with what I have seen here so far
