wire guage

[Devo]

I am mid way through the 12" dual rotor in Hughs book.

My mags are 40 000 in strength(if that's the correct term) not 35 000

I have read up on some of the 10 foot mills on the other power page & I see they use 2 strands of 14 gauge for 12 volts 34 wraps

this is 3 phase nine coils with 12 mags per rotor , hughs book is set for 24 volts

2 strands of 17 gauge 75 wraps.

I was going to go with 12 volt since I am kind of set up that way but maybe its time to make the leap to 24 or 48 volt.

the problem is I have access to 15 gauge wire not 14 so I am unsure what to do to gain peak performance. 2 strands of 15 is equal to 12 which has more resistance than 2 strands of 14.

do I use less wraps to reduce resistance then move the rotors closer or try 3 strands with less wraps & change the tsr of the prop or ??

I was thinking of 1 strand with 15 to 20 wraps with a small 1/4 " air gap just to see how the output compares but I don't know, all the testing gets expensive I just

want to finish this puppy & have it done so I can try it out-lol

I guess I can just order 14 or 17 through here , maybe that's easiest way but I already have some 15 from my 8 mag machine & can get more close to home.

any input appreciated

Devo

[picmacmillan]

hi devo..i have made stators with both #14,15, and 18 ..the difference between mine and yours though would be in the # 0f coils...i use 12 not 9...in any case, i tried to put as much wire as possibele, which want much anyhow to get the right size coils for my stator mold..i bleieve mine was 33 turns(2 strands)14" stator...my point is the resistance was low for the 14, and 15, but the 18 was too high..i am happy with the ouput of the 14, and 15 and it matched the mags i had at the time...in one scenario i use coils made of 200 turns of #18 wire and my resistance was 1 ohm per coil which is way to high..that was my learning curve stator ..hope this helped some..good luck..pickster

[Flux]

What do you want.

You seem unsure whether you want 12  24 or 48v. Are you using Hugh's 8ft prop or Dan's 10ft.

Your N40 magnets will need less turns but not by much.

If you can live with 24v I would think that you could manage 70 turns of 2 in hand #15.  Personally I would not worry if I could only get 60 turns in as long as your stator will run safely in a 3/4" air gap. If you want to go to a 10 ft prop try to be neat with your winding. For 8ft 60 turns will be plenty and if you use more you will be opening the air gap sooner or later.

For 12v you will probably have to manage with 40 turns of 3 in hand #15 .

For 48v  140 turns of single #15 or there abouts.

Try a test coil for your intended voltage, see if it will fit and check the cut in speed.

Flux

[Devo]

Thanks fellas, prop is "uncut" as I want to make sure I can match the output.

I will do a few test coils

Devo

[DanB]

I dont think 70 windings of two strands of 15 will fit in there -at least not the way I do things.  For 12V, I would do about 36 windings w/two strands of 15 and I think that would work nicely with a 9 - 10' blade.  Normally I use slightly bigger magnets for 12V machine and this same winding scheme (But I use two strands of 14) - but we have before made 12V machines with 12 gage wire and they worked fine, so two strands of 15 should work well - Ill just furl a bit early.

[Flux]

Devo

I think Dan is right, I used some wrong figures. You have an unfortunate choice with your #15. I am sure 2 in hand will be ok for 12v and it looks as though you can probably only use it single for 24v. You may manage enough turns of it single for 48v if you accept a higher cut in speed, I think 100t would be ok.

Be interesting to see how many turns you need with the grade 40 magnets. I would live with it rather than not use it, it will be ok, just not as ideal as #14 or #17.

Flux

[Devo]

Flux /Dan , I am busy as all heck at work but I will try to get the rotors together & some test coils together & post back this week before I go farther.

What rpm do you think I should shot for for a 10 foot prop , I know it can vary with the tsr just looking for an idea of what most are using.

Devo