3-phase motor conversion

[ruddycrazy]

Hiya Guy's,

           I just stripped down a 2hp/1.5kw 3-phase 440 volt motor I had laying around the workshop. This motor is brandnew and the thought came around this could be an easy conversion to a wind genny. Sorry if I'm way off the mark here but the motor is setup as a 4-pole with the 3 phase wires coming out to a side panel. Now as this is already wound 4-pole 3-phase can I get away with the windings and just machine the stator to accept cylinderical magnets. The machining won't be a challenge as I own a bridgeport mill with all the tooling and I was thinking of machining pockets to hold the magnets glue them in  then machine up a sleeve which only has to be 25-40 thou thick to help retain the magnets. Unfortunately my digital camera took a swim and is in the scrap bin awaiting a post mortem so I can't show a pic of the motor right now. I hope I'm not way of the mark here and any help will be apprecieated.

Cheers Bryan

[tecker]

 Not sure about the stator I seems this is up to your prop size and the magnets you want to use . The wire size for run should be around 16 gage some times using a smaller gage for start it a multitap ?  When machining the rotor make sure not to embed the magnets in the rotor and the leading trailing edges are aligned with core segments corresponding to the leading trailing edges of the coil in place . Plenty of good data in the back pages here

[Jon Miller]

doing a similar converstion to you but with a smaller motor about 1ph 3 phase.  I am going to leave the stock windings in but machine down the rotor because i have been informed that machining into the rotor will rob the magnets of power and that using a cage to hold the magnets in is the best way.  I will then tap each phase to a computer psu and use the 12 volts out of that.  I like this idea because it means a simple cheap job that should last.  

.

[wildbill hickup]

Good info here from Zubbly. Complete instructions on a motor almost identical to the one you have.

http://www.fieldlines.com/story/2004/8/13/191519/161

http://www.fieldlines.com/story/2004/8/13/214144/026

It includes a really neat idea for mounting disk magnets, take a look before you buy your mags, if you haven't done that yet.

Wildbill

[ruddycrazy]

Thanks for those links Bill today when I get a chance I'll count up the stator poles and get an idea of the size magnets I need. Also I'll take some photo's using my normal camera, scan them and probably throw them on my website under the projects section. That way I won't take up too much band width on the forcefield server. This looks like a top project where I can use all my resources and not break the bank making up a wind genny. Well the alternator part of it anyway.

Cheers Bryan

[ruddycrazy]

Hiya Guy's,

           Well after a big bout of whipper snipping I got to spend a bit of time in da shed so I measured up the motor. The stator is 3.380" diameter and 2-3/8" long, now as the motor is 4 pole there are 36 lands. On measuring the bore it came out to 3.855" diameter. The approx distance between 3 wires is about 3/4" so 3/4" round neo's would suit it perfect. Say I put in 3 per length and put 9 neo's around the circum. This would leave a spacing of 0.079" between the magnets which is heaps of space. Even skewing them 10 degrees would still work out ok I reckon. Sometime today I'll get those photo's taken and get them up here so you blokes can see what I'm on about but so far it's looking good.

Cheers Bryan

[kitno455]

9 neos around the circumference wont work. the mags alternate north pole/south pole up as you go around. odd number of mags puts two poles same way side-by side...

its a 4 pole, right? so maybe what you need is NNSSNNSS ? look for most any posting by zubbly. he has many rotors made just like that. watch out for how he handles cogging (skewed mags)

allan

[wildbill hickup]

I agree with kit 9 won't work. Read all of zub's material befor you start. For instance (and this is rough believe me but you'll get the idea. I you have a 4 pole and 36 lands then each pole should cover 9 lands. The magnet area for each pole should be just under the area of the 9 lands and as long as the pole. In Zub's layout you can see groups of mags 20 or so, all those mags in each group are either facing N or S then each group's polarity is reversed. So he winds up with group of 20 facing N, next group of 20 facing S, next group N, final group S. Each group passes under a pole and acts as one big magnet about the size of the pole.  The reason he uses the smaller disc magnets is they fit the contour of the rotor better, hence a smaller airgap. Hope this helps. From what I can see your building a motor almost exactly like the one he has in the post, so I would follow his instructions very closly including demensions.  

Wildbill

[ruddycrazy]

Hiya Bill,

          Yea mate I found and read all of Zubbly's diary's and I reckon I'm on the right track. I've sent out a quote to a bloke I bought magnets off before for 100 1/2x3/8 grade 45 neo's. As my stator is only 2-3/8 long I need to workout the amount of magnets i need and when I have have it all put together try it out. Well it's going to be a big learning experience for me and I must say a very exciting one too.

Well I can finally put my engineering machines to work on RE gear and that will put a good feeling in my gut.

Cheers Bryan