Posted: 03:10am 14 Sep 2005

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Hi Group , congrats Glenn on the new forum --and your new workshop-

I must say that Matt Lyons idea of replacing the ceramics in the f&P rotor with Neo's is an outstanding idea --I have done it --- the results will amaze you - nearly 4-5 times the power output .True.

I broke out the first ceramic magnet with a 12mm chisel and from there around the ring the magnets just popped out ,mostly without any damage.

Cleaned up the inside surface a bit --mistake- leave it rough(but have no jagged pieces sticking out or onto the steel banding) ,needs to be a bit rough ,as the neos sort of stick better and don't want to become "friends" with the adjacent ones.

place the neo's at a slight angle -10' - or so, north,south,north,south Etc.

go back and align them all so they are as perfect to the eye as possible.

sticky 'gaffa" tape (the type with the cloth in it is stronger and dosen't stretch ) is gently placed around the inside of the magnets,just smoothing around as you go and gently making sure you press the tape onto the mags and plastic surrounds-got to carefull here ,as if you don't stick it evenly and firmly the Polyester resin will run out -

stick a band of the same tape around the outside of the rotor hub keeping it just a bit above the top of the magnets-oh, by the way , inside tape should be just above the top of the mags also.

Now you have an inner and outer tape circle with the neos just below the surface---this should give you a small shallow "dam" when the polyester is poured.

set the rotor on a bench so it's level --use a spirit level in both directions-this is important ,as the resin will spill out the low edge if not level---

mix the resin, around a half cup full --carefull, don't put more hardener in that the instructions say-

pour the resin gently from a start point working around in on e direction letting the air bubbles sort of flow out as you go.

Just double check and top up here and there til the whole 'ring' is sort of 'very full"

now, you can set a 150-300 watt paraflood under the job -not too close-to gently increase the warm flow of air.

go away--- leave it alone- have a smoke or a beer - but don't touch it,right.

next day you can peel the tape off and you should have a perfect finish --if a few little dribbles or whatever are there, gently sand then off or use a scraper or file (gently,we don't want to score the neo's )

Now , Matt Lyons from Melbourne (he's got some postings here), is the guy that can really help you obtain the Neo's at the right price . He will do the conversion for you if you like,

Bruce

Posted: 06:01am 14 Sep 2005

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This site may help. 

http://www.aussiemagnets.com.au/Merchant2/merchant.mv

They dont have the 30x10x3mm neos, the closest are 25x10x3mm or 30x11.5x3.3mm. For 56 25mm neos would be ~$86, the 30mm neos would be ~$165.

I wonder the 5mm thick are more suitable ? might not need banding if they were used, although.....??

Posted: 11:32am 14 Sep 2005

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Hey Bruce, good to see you here.

Whats the cogging like after the conversion? And how does the new hub perform at low speed, say for a VAWT.

I read that the F&P is good for 1 watt per RPM. This explains why we get about 300 watts at 300 rpm, when matched to a 2 meter propeller. So after this hub modification, a grunty VAWT at 100 rpm could make over 400 watts!

Ed at http://www.windstuffnow.com/ has a new VAWT design that might work well with the F&P as a direct drive. Would make for a very easy to assemble and cheap windmill.

Glenn

Posted: 03:32pm 14 Sep 2005

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Glenn would the Oatley motor conversion be viable if it had more than just four magnets? are they ceramic?

Posted: 10:23pm 14 Sep 2005

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Nah. Its only got 4 brushes. The only way I could see to increase voltage to 12v or more was rewinding the armature.

I played around a fair bit with these, no luck. 6 volts was all I got. You would have to gear them up, or use a string of them in series.

Posted: 03:21am 16 Sep 2005

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Bruce did you have any problems? is the f&p rotor strong enough to be used with neos? does it flex or warp and touch the stator?

Posted: 09:03pm 15 Oct 2005

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hi Storm-- the plastic rotors do warp or flex a bit -noticed this after I removed the ceramics- So what I did was epoxy glue a 6mm al disc(300mm) onto the back of the rotor ,then drill and tap for the prop attachments. this makes it quite sturdy .

With the Neo conversion you have to be pretty-well spot on with your placing the mags otherwise if even 1 is a bit raised it will scrape ,and this causes a lot of friction -you want absolutely no contact at all.

bruce