Blade calculation help

[Treehouse]

Hope someone can help me... I made some measurments on my altinator. First off its  3-phase 8 x neo45's 1"x2"x.5" single 10.5"rotor and 6 coils, 170turns of 14ga wire. Wired in star. Right now I'm using Hugh Piggot's 4' prop and I'v never seen more than 1-2amps usualy hangs around .100ma oh and it's a 12v system. I have with the help of this board come to the conclusion that I should be using this on a 24V system, but I'm running a 12V system. So I was hopeing rather than make a new stator I could make some new blades to match my alt. for a 12V system. So windspeed aside here are some measurments I made.

RPM - Current

180. - .010 ma
     
195. - .100
     
210. - .200
     
225. - .300
     
240. - .450
     
255. - 1 Amp
     
     

The wood I would like to use 2"x6" Can anyone help with the measurments???

Thanks Dennis.

[hiker]

sounds like its not wired up right...[gotta be]

is there lams behind your coils?[single rotor right?]

try delta--heres a pic. of a 9 coil layout[3 phase]

oh--whats your open voltage output?....[no load]

[Treehouse]

no there are no laminats or a second steel rotor behind the stator.I would like to try delta but buried the connections to do that.

[hiker]

all i can  think of its  has to be  the way you wired it up..

maybe a short somewhere..[miss wired]?

i would try a new stator..

 my little 8" dual rotor alt[sawblades]3 phase[star] 9&12[ceramic powered] easyly lites up a couple of 50watt headlites[60v open] -a little past slow speed on my drill..

waiting for for some neos i ordered from the dans--there close to 1by2 1/8"thick..

i will cap of the ceramics with the neos--should give a few more amps and volts...

[Flux]

Yes you have the 24v winding. The best solution would be a buck converter but not very practical unless you are familiar with such things.

Plan 1:  try a drastic increase in the air gap if you can do it, that will get you out of stall.

Plan 2:  Try increasing prop size to 5 ft keeping to tsr 5.

Neither method will give you the full potential of the machine. Even if you get out of stall, the winding resistance is four times that of the 12v one and the efficiency in reasonable winds will be very low.

Even with the 5 ft prop the performance will be below that of the 4 ft one with the correct winding.

I think I would be tempted to see if it is possible to get into the series connection between coils with a bit of careful work with a dremel tool or similar.

If tou can make yourself 2 star windings of 3 coils you can add a second rectifier to make it a parallel star winding that will be equivalent to the series star of the normal 12v stator.

Find a friend who needs a 24v stator and make another one if that fails.

Flux

[hiker]

225 rpm and only 1 amp--its a wiring prob.....

and of course no lams and only a single rotor..

seems to me you would want the mags as close as possible to the coils..

hacksaw into  the wiring joints and see if its wired up right..

or start over with at least some lams behind the coils..

come to think of it -its got to be a wiring prob. if its stalling and at such a low amperage output --there a short somewhere[or misswired]--thats whats causing the high resitince[hard to turn].......im through.

[DanB]

Did you ever get around to trying a delta connection?

possibly a bit of a wide airgap and a delta connection would improve things a bit.