I ‘m planning to build a direct drive jet with the SSS inrunner. Got a stock aluminum tube to put it in, od 60mm id about 57mm. Obviously just putting the motor into the tube won’t result in good thermal contact. Assuming the motor has 25% thermal losses, up to 1 kW need to be dissipated. So I was wondering what you guys do to ensure good thermal contact between motor and tube housing. I heard about filling the tube with oil so far. What about heatsink epoxy?
we have used Copper tape / aluminium foil and thermal grease, “thermal epoxy” will probably work as well but hard to get it apart.
Yeah, thermal paste like they use on computer CPU’s seems to work. Not too expensive either, just make sure the motor is covered in it.
With outrunners you are right. Outrunners leak a lot of field strength and thus any closed loop conductor around the diameter of the motor would act a little bit like an eddy current brake.
In an inrunner there is already the stator iron around the outside diameter of the motor and the motor housing itself. Any additional iron or metal there won’t hurt much as very little field escapes this assembly.