Jeremy Harris wrote:
I'm no expert in magnetics, but I wonder what the impact on performance would be for a rotor machined from a big diameter solid bar of something like Delrin, with peripheral holes CNC bored right at the outer edge to take the magnets, revolver-style? Maybe a very thin wind of carbon fibre tow around the outside would hold the whole thing together at high rpm?
this is what i have floating in my head . ill hopefully see dave at performance fiberglass tomorrow and see if hes willing to take a shot at a carbon fibre core. i had thought derlin , ill see if i can find info on how it reacts to heat .
Jeremy Harris wrote:3. Winding flat, overlapping inrunner coils should be fairly straightforward, these could then be wrapped around a slightly oversize dummy rotor mould, then encapsulated. Ideally the windings could, perhaps, be bonded to a iron outer ring at the same time, to enhance thermal conductivity as well as complete the magnetic circuit. I can't see an obvious way to make a motor without an outer iron can, without the added complication of having an outer ring on the rotor, with another Halbach array.
although i like the idea of dual halbach array ill keep it as easy as i can for now. the slightly oversized dummy rotor as a form for windings is precisely what i had in mind . dug the wood lathe out of the corner for that task, sacrificial mould . i was thinking of wrapping the od of the windings with a long thin gauge iron sheet untill that wrap was the same thickness as the windings ?
Jeremy Harris wrote:I rather like the idea of a very big inrunner, as it has the potential to give high torque and dissipate heat a bit more effectively than an outrunner. It would be pretty easy to fit fins to the outer case to enhance it's thermal properties, something that's hard to do with the other configurations. Although high efficiency is very desirable, I think lot's of us would accept an efficiency loss if the resulting motor was affordable and easy to build, perhaps from a kit of CNC'd components.
by no means do i expect to see any efficiency numbers i can brag about but may be rather neat if it makes decent power and i can assemble it for less than $100 . i spend $100 a month on beer so this can take a step up the priority ladder for a week or so.
M.E.N.S ex pres and charter member.