Magnet?

[farmerfrank]

Hopefully someone has the answer. I have plenty of 1/2 x 1 x 2 inch magnets. Now is it more practical to say crowd 18 or so onto the rotor or is it better to put maybe 12 doubles,end to end, to give a dozen magnets 1/2 x 1 x 4? The coils would be longer,making better use of the copper,but the angular velocity would be quite different between the outside and inside magnets. Any ideas,comments or suggestions?

the farmer

[Flux]

Your question is far too vague to answer.

How many is plenty?  How can you compare 18 with 24. What are you trying to build?

There is no point in using more magnets than is needed for the power you want to produce. I have no idea if you have a specific size machine in mind or whether you are trying to build the biggest one with the magnets you have.

In general you will do better with more poles rather than group into bigger magnets with less poles, but there are other factors.

You say crowding 18 magnets compared with 12 long poles. This is not a reasonable comparison, crowding magnets is not cost effective, if you are not prepared to use discs big enough then you are not going to benefit.

Also it is not fair to compare 18 magnets with doubled up 12(24 magnets), but if you do it right, the 18 spaced properly would give the double size 12 a run for their money, but not on the same disc size.

Flux

[farmerfrank]

Thank Flux. Your right I was vague. I have 1/2 inch thick, 18 inch diameter rotors and am now trying to decide what would be the best use of my magnets. They are 1/2 x 1 x 2 and was hoping to go either 18 or maybe even 24 per rotor or would that be pushing it. Once I find out roughly what the generator specs are I will make the blades to match .Shooting for a 36 volt setup.

This is actually my third machine. The others work nice but now I want to tune this machine rather that hit and miss. Again thanks for you reply

[Flux]

24 poles on 18" diameter is quite nice, I wouldn't mess about stacking magnets together.

I would look for a test coil of 40 turns, probably 2 in hand #14 if you are careful.

That should get you nicely to about 16ft as long as you can keep line resistance right down.

Flux

[farmerfrank]

Well thank you very much Flux. Do you keep all these numbers in your head?haha

I just happen to have a 90# spool of #13 that would probably work out nicely.

Again,very much appreciated