another coil question

[Goahead]

Hi all

So many posts about wire size, but i just wanted to be cleared about this:

A cousin of mine has some 1.5mm diameter wire for coils.

I'm building a 10' machine and i was aiming for the 24 volts battery bank.

magnets: 2"x1"x1/2" with Coil turns not decided yet.

I was hopping to buy some 1.2mm wire for the 24V coils (maybe 100 turns each coil), but since i can get my hands into 1.5mm for free my question is?

• 1.5mm wire coil, +-100 turns will the size fit in the stator jig?
  
• Would it be better to aim for the 12V +-65 turns instead, since its near the 1.6mm that everyone use for 12V?
  
• Can someone point me for an approximation in wire meters (not Kilos) for the 1.5mm that i will need for 9 coils?
  
  

I can say its near the AGW15

AGW14      1.63

AGW15     1.45

AGW16     1.29

What a dilemma ..at least it is for me

Nice turbine displayed in front of 'Cool House'

Photo Size is limited to 150K bytes and/or 640x480, please refer to Frequently Asked Questions... DanG

Any help appreciated

Best regards from Portugal

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[Goahead]

Sorry for the size of the last picture..corrected now

Thx DanG

Its my recent build "Modern cubic" house (470m2 of space inside)..lots of big windows in the other side (south), very efficient, good solar exposer...but that's another story...

Found some answers in forum about the 1.5mm wir, so let me refrase my questions:

• My calculations point me to 75 turns for 180rpm cut-in (24V)...Am i wrong?
  
• 1.5mm wire is ok for 16A for each phase , so i could reach the 1.1kW without burning stator...
  
• will 2 in hand 1.5mm still fit the coil jig for the 24V?
  
• AWG15 is 0,0147Kg per meter <-> 1Kg has 68,2 meters
  
  

For what i read in forum,i may need +/-200gr (70turns) per coil, that's 2kg of wire.

Did i answer the questions of my previous post..or am i way out of the road!

Thx

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[scoraigwind]

Can you just fill in a few more details?  

Number of magnets per rotor is 12?

Diameter of rotor is 300 mm? Or more..?

grade of magnets is 35/40/45...?

Connection of coils is series/star?

What is the angle on the tips of the blades?  (just to give me an idea of their speed)

sorry to be so boring but I can't recommend a design until I know these other factors too.

[madkane]

the best idea here seeing as the cable is free just do a test coil and see what it can do then just add or subtract as needed

also amke an estimate on the length and you can pin down coil resistance  to near enough to guestimate what it can do before built

[Goahead]

Hi Hugh

More details:

• 12 Magnets per rotor (2 rotors)
  
• 300mm Diameter rotor (didn't get the disk cut yet but they should be 8mm thick)
  
• Grade N50 2"x1"x1/2(at least that's what vendor claim when sold me the magnets)
  
  

There are in inches cause they came from USA

• Connection will be in star..for what i have read here,it seems the best option.
  
• The angle at the tip is very small...around 2º
  
  

I would say along the blade stations angles are: 12,12,6,4 and 2º

Hope you can give me details/tips

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[Goahead]

Help Help.

I want to wind coils this week, but i want to start with right numbers!

My calculations are:

series/star connection

Air gape: 0,12mm

Stator Thickness: 1,27mm

9. coils
   
24. Volts
    
    

(the rest of info in previous post)

Cut-in:

140. RPM 97 turns/Coil
     
170. RPM 80 turns/coil
     
180. RPM 75 turns/coil
     
     

Now..can the wire thickness affect cut-in voltage? for what i have read no...only amps.

If so...

I need feed back if someone already tried 1.5mm 2 in hand, and how many turns did you get inside stator of a 300mm rotor (10' machine)

It would really help to begin winding coils with info from your experiences.

This may help others:

Thanks in advance

Goahead

[scoraigwind]

sorry Goaherd!

I forgot to come back.  Sometimes I do not look a this forum for long periods.  I have so many people on my case :-)  sorry

Anyway I don't think you can do it with 2 in hand 1.5 wires.  Not with a 12.7 thick stator.  You can only get about 45 turns at best and this would mean quite a high cut-in speed.  It will work, but not so well in low winds. I always find it hard to predict the flux of grade 50 magnets.  But using two in hand I do think the speed will be too high.

If you must use 1.5 diameter then maybe try making the stator very thin (9 mm) and winding 60 turns of 1.5 mm wire single.  I think this will work well at low power.  You might have to increase the air gap a bit if it stalls with low battery voltages.

A good place to start is by winding a test coil and see whether it fits the space.  If you can do this and get enough turns then maybe it will work out not too bad once the wind is blowing well.  But I suspect you can only get 45 turns and then it will be rather fast.

Another way is to make the stator very fat (16 mm) and try to get 60 turns and hope the magnets can work well across the big gap.

There are a couple of ways to use up your 1.5 mm wire and a chance it could work out.  But I would choose some 1.4 mm wire and wind 53 turns with 2 wires like that instead.

Have fun

[Goahead]

Thanks again Hugh

Made some experiences this weekend, and got to the same conclusion...

i Couldn't put more then 50 turns 1.5mm 2 in hand.

Im back to the original plan... 2 in hand of 1.2mm

I have to buy that thickness, since the 1.5mm was free to get

I cant measure the grade of magnets...just have to trust the Chinese vendor, so i may expect trouble in Air gap in the end of the project.

To be sure, i better stick with the plan and forget the 1.5mm.

Tested the blades this weekend (windy day) and the run like hell!!!

Couldnt measure RPM but i must assume more then 120RPM, and i started to hear a whistle from the blades.

That was a danger test, since i didnt have any type of break...but it was fun

Ill keep everyone posted as soon as a have more pictures of the work in progress.

Keep it Green

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