Neo Mags and tested

[mrlindner81]

I got my neo mags last weekend and put them on my small wind genny.  Its a 4 foot 3 pine blade with a tsr of 7.2 and the magnet plate is 4" of 3/16" mild grade steel with 8 3/4" N40 neos.  The stator is 6 coils of 400 turn 26 awg wired in delta.  I put it together and put my drill on it and at 400 rpm it made 14.7 volts and hooked to a 12 volt battery it made .110 amps.  At 1400 rpm it made 51 volts and hooked to a battery it was at 3 amps.  So i took it down to the lake and put the blades on it and in a 10 mph wind it was making around .85 amps and when the wind gusted up to 18 mph it was at around 3.4 amps.  So I decided to test it in higher winds so with it hooked to my utility trailer I drove it down the road and at around 40 mph it was saying 9.5 amps then i heard a bang noise and then grinding.  I stopped and looked at it and found the neos to be missing on one plate and some on the other plate were gone too.  I touched the stator in the middle of the coil and it was cold so I dont think it overheated but i only had the magnets superglued on and it didnt like the 2000+ rpms.  So I took it all home and looked even closer and one of the blades got hit by a magnet flying off and split at the end of the blade.  I found all of the magnets and to my suprise none of them were broke and all were really strong magneticly.  So it looks like this weekend I will be making a new blade and gluing the magnets back on again.  I will ge epoxing them on this time though.  This whole thing is fun and I think it isnt too bad for my first generator even though its not the most effecent at least it works.  Hopefully I will be starting on my next one and it will be a 6 foot with 8" magnet plates.  Thanks to this site for all the knowledge and help its a great place.

[paradigmdesign]

Man, thoes little genns sure get up there with the RPMs!  My turbines max RMPs is going to be arround 225.

[ghurd]

Yea they do.  My next one is aimed at 330RPM cut-in at 6.5MPH!

But it won't need much for a tower.  :-)

G-

[zubbly]

hi mrlinder81,

i would like to make asuggestion if you don't mind.

before you glue those mags back on, get 2 plexi glass plates cut and drill the pattern of the mags in it. then use a few stainless screws to attach (6 per plate) the plexi glass plates to the steel plates. the plexi glass plates can be a little thinner than the thickness of the mags.  then glue in your mags. the plexi glass should prevent your mags from comming off.

plywood would be better than nothing. just use a few coats of wood sealer on them first to seal them before attaching to the steel plates.

zubbly

[mrlindner81]

Thanks for all the comments.  Zubbly the plexi glass sounds like a good idea since i dont really expect to get 40 mph winds but I don't have a furling system on this one and you never know what is going to happen.  This one cuts in at around 380 rpm at 6.7 mph and start up is 8 mph.  In a 15 mph wind its spinning at 800 rpm.  This is connected to the side of my house and I dont really want the mags flying off again.

[Shadow]

Or even better than plexiglass is Lexan, a little more expensive but unbreakable. I've had terrible luck cutting plexiglass.

[mrlindner81]

I have cut plexi glass before and you have to go slow or it cracks.  Its more like burning it than cutting it.  I dont want to put to much money in this due to its limited power output it is pretty much maxed at 4 to 5 amps at 12 volts and I have around $100 in it so far due to rebuilding with neos and reworking the bearings.  I have a bearing like jerrys now with a 3/4" pipe and small bearings.  I might use lexan on a bigger one but it would be worth the cost there.