First small induction motor

[Devo]

This is pretty plain ,I wanted to make a small genny about 50 to 70 watts for my brothers camper. not sure if this will do the trick but here's what I have so far.

Then I pushed the shaft out of the centre & a 1" square pipe fit over it perfectly.

I then put 2 1X2X1/2" neos on top of each other on all 4 sides this just barely fit

in the centre , I wish I had left it like this or bought 1/2" thick steel flat stock

ubnder the mags but instead I had 4 ceramic mags around so I put them under the neo's in the end but they were thinner so there is a good 1/8" plus clearance now.

This is the shaft with mags installed

I used the "stock coils" & rectified each with a bridge rectifier then put the 2 rectifiers in paralell. here are the stock windings

Then I tested it on my drill press

I got 16 volts (open)at 210 rpm

this gave me 7.6 watts or .64 amps into my battery at 12 volts

at 280 I got 22 volts (open)

which gave me 26 watts or 2.2 amps into my bank at 12 volts

the numbers seem to drop after that on my drill press when I go higher, I am guessing the higher gear ratio kills it.

I did try it at 800 rpm open & got 48 volts I think as it shook the wires out of the

volt meter (motor was off centre in the chuck-at 800 rpm it really shakes!)

I also have 8 180 volt 1/2 hp dc pmg motors the figures on it are as follows

210. rpm , 41 watts into the battery bank
     
280. rpm , 66.7 watts into the bank
     
     

again when I move the belts to a higher ratio the output drops (need to get my lathe home.....)

Devo  

[Jerry]

Hi Devo.

When I do the 4 pole conversion like this I get much better results by a sires perelell configuration of the coils.

Your actully bogging the drill press down. Once you do the coil reasignment power will go up drasticly.

NTL has some nice curved NEOs that will make a major increase in power also. I've seen over 300 watts from a motor with these specs at around 500 rpm. Just get the coils matching the load, get curved NEOs and you'll be make some power.

                       JK TAS Jerry

[Devo]

Hi Jerry , thanks for the comments.

What exactly do you mean by

"sires perelell configuration of the coils"?( I will do some reading on your posts  again to see If I can understand it correctly)

do you mean wire the rectifiers in series? or the coils themselves?

I have been following your posts lately & NTL's on the #29 curved neos.

I have a few of these motors around so I would like to make use of them..

Thanks again

Devo

[nothing to lose]

I still have some arcs if you decide you want some later, e-mail me.

 I might have a motor about like that here myself, storm just hit like WHAM so I can't go look right now. It was nice out a minute ago.

I think it would help also if there was a more solid path for the flux to flow under those magnets. Not certain. I figure the ceramics may actaully be hurting more than helping. A thick wall 2" tubing might be better if you could find something like that you could press fit over the 1" or weld on.

 I don't know how you bonded the magnets and everything together or if they will come back apart very easy. I kinda wonder if the rotor will have alot of stress on the magnets built up that way.

[Devo]

Hi NTL , I use cold permatex cold weld on all my mags , it's fast & easy.

I am going to make a mold & cover the final centre in resin. You will see an E-mail from me today on the mags,still not sure on the wireing...I have a bunch of # 15 magnet wire maybe I should try to rewire the stator but I only need 50 to 100 watts

but heck more is always good:-)

I will play a bit more today , I was thinking about pipe over pipe like you said or just cutting some flat stock to put under the mags or the 6 sided pipe you can buy(not sure if 6 poles would be better than 4 in this set up). Round pipe may be better with the arc mags around it.

Thanks for the input

Devo    

[asheets]

What was this motor originally?  It kinda looks like a frac horse Dayton...

[Ungrounded Lightning Rod]

Don't weld the magnets!  (At least not with HEAT, as opposed to glues with "weld" in their names.)  Heat demagnetizes them.

If you can't find curved magnets you can always use flat magnets and put a d-shaped steel/iron pole piece on top of them to reduce the air gap.  You can use solid metal rather than laminates since the field stays pretty much in place in the pole piece rather than dragging through it as things turn.

[Ungrounded Lightning Rod]

If you skew the magnets by about the width of one stator pole, rather than having their long edge EXACTLY parallel to the shaft, you'll reduce or elminate cogging, making it easier to get a mill to start spinning when the wind starts back up after a calm.

A little cogging is OK, as long as it takes less wind to start the mill than it does to spin it up to cutin speed.  But if you have enough cogging that it will stay stopped until the wind is above what would spin things at cutin speed you lose opportunities to charge in low winds - when you need it most.

[nothing to lose]

"Don't weld the magnets!"

I hope it didn't sound like I meant it that way when I said weld on 2"  square tubing over the 1" tubing. NO, I would never suggest welding any magnet