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Stator casting and best casting resins ? Answered

I am curious which would be best for casting my 9 coil 3 phase stator ,Cyanate ester resin ,or Polyester resin?I also curious if it would be best to cast all coils together as a whole or would individual castings work better for heat dissipation? The individual picture just for example. Thanks for taking time to help :)



If there is any way you can cast this thing under a few PSI of vacuum, you'll get all the voids out, and replace them with resin, again keeping things cooler.

Lemonie is correct in that the entire stator should be cast as a single piece. Gluing parts together won't be as strong and something will go out of alignment. Steveastrouk is also correct that a filler should be used, but avoid metal powder (electrically conductive!) and "microballoons" (they speed the cure and increase exotherm.)

One possibility is a polyurethane casting resin (see http://www.uscomposites.com for Easy Flo 60 as an example). These are usually intended for larger castings and do not exotherm quite as badly as other resins. But they cure too fast for use with fiberglass cloth or mat.

I would try a very slow epoxy, cooled to just above freezing and kept cool. It would take a very long time to set, perhaps several weeks, but that would minimize the distortion caused by exotherm. (Epoxy doesn't smell bad like the styrene in polyester resin, a big plus.)


I agree with lemonie, but it is a good idea to fill the resin with something, it can increase the conductivity, reduce shrinkage, and helps stop a thick casting cracking from the exotherm. Don't use a microfiller, go for something like powdered limestone.

I don't understand using powered limestone ?can A explain for me please,and thanks for your guys help ;

Limestone (or marble) powder is a filler. A "filler" is an additive you mix in your resin, it saves resin, and, because it is more thermally conductive than resin, helps the casting cool. The picture you posted looks like it shows a filled resin.

I'd use the polyester, heat dissipation isn't going to be that different, and cast the whole thing in one. L