my new mini gen

[willib]

got a new axial flux minigen in the works

i'm using 7/8"dia x 1/2" mags

the rotors are unique lol

almost 8" dia

suprizingly it didnt take that long to cut by hand

my "lathe" needs more power though , its just a coppier motor , pwm powered.

i'm thinking of using the motor as the bearing for the alt

its a 16 mag , 12 coil machine (4 coils per phase)

and i will be using 0.045"dia wire

the rotors are almost 8" dia

the coils are a departure from my usual 2x magnet dia , i've tried to optimize them a bit

instead of 1.75" dia ,

 i'm toying with the idea of making them 1.34"dia

10 turns wide x 9 turns deep giving 0.111 ohms per coil and 0.445 ohms per phase and using just 22'of wire per coil

the hole will be 0.437" dia.

i may not need that many turns though because i was getting 2V per coil at 83 RPM (88 turns), on my 11"dia testbed.

i'm figuring 114RPM to 150RPM for the same 2V on the new machine

[willib]

i used a 8" skillet for the rotor





My "lathe" lol





a shot of part of the stator with magnets in red





iron filings , there is a magnet in there somewhere

[ghurd]

I thought you were crazy when you said 'cast iron skillet'.  Looks good.

What does the 'lathe' use for a cutting tool and holder, or does it just spin the magnet disk for testing?

G-

[willib]

 i'm sure it sounded wacky when i mentioned it , but it works !!

the 'lathe' uss a tightly held file as a tool holder lol

and spins the rotor and mags at over 600 rpm

the rotor in the photo is tapped with a 3/8" thread and spins very true

the rotors are 0.165" thick i wish they were a tad thicker though

but they are very flat , much flatter than the imported ones i was going to buy

it didnt take that long to cut the flat out of the skillet because they are cast iron (soft metal), probably less than 45mins with a hacksaw

[harrie]

Hi Willib. Now that is what I call ingenuity, using available household stuff. I think my wife would kill me tho, if I took her pans. Ha. keep up the good work, and neat pictures. Harrie

[willib]

got the other rotor cut and installed the magnets

it took twice as long with a smaller hacksaw than i used before

it should be easy to check the effeciency of this one , since it is built on a DC motor

[gotwind2]

Great work WilliB - I will follow your diary with keen interest.

Prehaps when finished, and generating power you could write some plans on making your '8" axial flux mini generator.

Keep going - your photos are good and the correct size, unlike so many.

Gotwind

[vawtman]

Neat work Willib and your idea got me looking into the pots and pans section of our kitchen previosly unexplored by me.The wife asked why are you looking at that?Then she said "NO YOU CANT HAVE THEM FOR YOUR WINDMILL"

 All i did was look at a pan!Funny how she picked up on that.

 However 2 of the right sized pans may sneak outathere used has endbells for the axial.

 Ill by her new ones for christmas LOL

 Good luck with your project and way to think "out of the cupboard"LOL

[willib]

i drew a crude diagram of the spindle i plan to use when i'm done with the DC motor

the spindle is 5/8-11 threaded rod , i had to file the dia a little to get the bearings to fit  

just have to locate a 5/8-11 tap and a tap drill

vawtman your wife will be happy i havnt used jewelry yet in my windmills

[willib]

it should be done ( cured )in half an hour

60 turns of 0.045"dia wire

[willib]

oops just bent the shaft!

should have used jacking screws

luckily there are no broken magnets

i guess 3/8 threaded rod is no match for neos

i dont recomend doing it this way , but it has worked for me in the past, on my large testbed, which BTW HAS jacking screws, doooh!!

i thought i would bring the mags closer than 5/8"

considering my coil is just 0.260 wide i was shooting for 0.270 , close enough

so i took the top mags off

dropped the upper plate a little

then was in the process of assembling the upper ones back , when the shaft bent

i can unattach the 4 pairs fairly easily lol

on the bright side the coil worked as planned

2.5V at 240 rpm , cutin should be around 281 RPM @ 14.5V ,i think

this is for a 16 pole 12 coil dual rotor machine with 7/8"dia x 1/2" N40 neos

Rotors are 7.75"dia

with 60 turns of 0.045 wire and 0.075 Ohms per coil , and 0.3 Ohms per phase

14.8' of 0.045"dia wire per coil

coils are about 10 turns wide x 6 turns deep with a 0.45" hole

final dia is 1.35" x 0.27" deep.

[ghurd]

I like the Fuzzy Neo.

Was turning a conversion rotor, test fitted some neos to get an OD measurement...

Hand turning to get different angles.

Crap from the mini-lathe bed jumped up all over them. A serious mess.  I should clean the chips out more often. LOL

G-

[willib]

my new 60 turn testcoil was more like 50 turns

for a 12 coil machine (4 per phase)

i need approx 2.56V per coil to get 14.5VDC ?

after some restesting of the new coil this is what i get

 RPM  Volts

 277  1.3

 352  1.5

 562  2.56

something is not right!

i am beginning to wonder whether making the hole so small is the problem?

i wonder whether 50 turns with a 7/8" dia (normal) hole at the same rpm would do better

[ghurd]

I think that's what I was talking about before...

Maybe a bigger hole, and a few less turns will work better?

G-