Minigen update

[willib]

I think its about ready to fly!

it starts charging a 12V batt at about 220 rpm , and the blades will go 220 to 280 RPM in a 7mph wind , lightly loaded , so this next test is not only for the alt but for the blades also.

very soon i will have more data on its performance.

[willib]

Sorry to be so brief in the origional post.

i believe this gen will kick a** !

Time will tell i suppose

Yes thats a plastic garbage pail, yes the rotors are cut from cast iron frying pans , yes thats a recycled vcr head for a hub

to recap it qualities ,

it is a 16 pole dual rotor Three phase with thirty two 7/8"dia by 1/2" neos

12 coils ( 4 per phase)

each coil weighs around 55g ( some a little more some , a little less)and has around 78 turns of 0.045" dia wire.

the coils are a little less than 1.75" dia , with a 0.46" hole , which by the way is the distance between magnets

stay tuned , the future looks bright , i've got a larger one in the works , not so mini

[TomW]

willib;

Yeha! gotta love using what is around.

How did you cut the rotors from the pans?

What capacity is the garbage pail? Hard to get a feel for the scale. The pail looks like a longer than normal 5 gallon bucket but that would make the unit bigger than it seems to imply in your other comments?

Cheers.

TomW

[TomW]

oh, duh.

Finally recognized the beer can for what it is.

Cheers.

TomW

[willib]

hey tom !

yes the pail IS a longer than normal 5gal bucket ,it origionally said xxx Township Recycleables , and something about " under penalty of law .. .." but the owner gave me two , lol

as for the iron skillets , first i drilled a hole in the pan then i used a hack saw to cut the center out, following the outline on the pan.

[willib]

almost forgot ...

the blade hub is/was two 5.25" hard drive plattens with blue foam inside

things i bought are

the mags

the skillets

and the stainless nuts and bolts

the foam for the blades

everything else i scavanged.

the tail is a plastic pipe with cedar shingles

the bucket

the vcr head

the white plastic stator mount

the wire , all free!

oh yeah the wire connectors , i bought them too

and no lathe was used.

but i do have a craftsman drill press that takes my Ryobi portable hand drill and holds it sort of verticle

the Ryobi i got from a garage sale $1 i thought that was a bargan

the drill press was also from a garage sale that was expensive $10.

[Jerry]

Hi Willib.

Great work. I have your same problem. Every day I see things of all sort and find my self asking. How can I make a wind generator outa that???LOL.

Thanks for shareing your neet littel machine with us.

Keep us posted and updates.

                        JK TAS Jerry

[tecker]

I too get a bang ( nothing has really blown up But we've vented some smoke a few times)out of useing available things ( It's not always junk it does seem to be though) .I really like the up grade process I get into something a little better than what was and first thing you know I 'm rippin up a a unit and get caught up in rebuilding it . I know you really put a lot of thought into this unit . Looking forward

to seeing the results and your data logger good stuff.

[WXYZCIENCE]

Willib, I see one of the blades is kinda pink around the edges. Is that just the lighting? What are you going to do for a yaw bearing?


I have not been able to work on anything last couple of weeks. Winter slows everything down here. Just have to stay alive is fun. Glad to see it coming together.
Joseph.

[willib]

it is pink ,i used the pink foam on that one.

i took the minigen out for a spin this evening, my toes are still froze i think.

anyway no hard data , but i did see it go to 2.3A into a 12V SLA battery at a wind speed that was high 7 and just touched 8 mph for a second.

it wasnt very windy at all ! Damn

there were some  people on the hill i use to test my gens , they were slegh riding on our first real snow ,two days old and hasnt melted , we didnt get much snow , about two inches is all thats left.

the hill overlooks the highway and is well above the treeline , in all directions , its a great place for testing.

[ghurd]

Nice!

G-

[willib]

sorry for not responding sooner , thanks i did put a lot of time and thought into this. i try not to think of much of anything else can ya tell?

i have a general question ,in the graph below is a new plot of Volts vs Amps output of the minigen ,the last two points are extrapolated to fit the curve.

since V/I = R the numbers seem to be approaching a resistance value , but i'm not sure what that value means?

 12.5/.13=96

 12.6/.29=43

 12.7/.42=32

 12.8/.58=22

 12.9/.66=19

 13.0/.80=16

 13.1/.95=14

 13.2/1.1=12

 13.4/1.5=8.9

 13.6/2.03=6.7

 13.7/2.3=6





it cant be the resistance of the alt , because the line to line resistance is around 1 ohm , i suspect it could be the resistance of the Ammeter plus the resistance of the SLA battery in parallel with the diode resistance , i just dont know? any ideas

the test was conducted after i took the alt out for a spin , i was trying to get a better idea of the power that i got out of the alt today, same battery , same everything except i was powering it , not the wind ,

ive estimated that the battery voltage was a least 13.6V when the alt passed 2A, today.

thats 27 watts . wow !

[willib]

Have you had a chance to use  arbors i sent ya?

Ghurd , thank you so much for the wind gauge !

the blue foam disk , fits between two 5.25" HD plattens like on the minigen prop hub

[willib]

just a followup on the previous graph/ question.

i've plotted the resistance values calculated from before verses current





maybe i'll have to load it down more (with more wind) to find what the asymtote is

[ghurd]

You are welcome, and thanks for the jpgs.

No. What will fit the arbors won't fit anything else (mostly bearing troubles).

I have a couple ideas depending on finding a 3/8-26 tap (bike threads), locally, no minimum order, or price not listed in £.  It's always the silly things that slow me down.

Searched again just now. JTS Machinery may help.

[willib]

If you need more drawings just ask , they only take a few minutes to do !and its fun.