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Forum Index : Windmills : Neo conversion
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| brucedownunder2 Guru  Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Yesterday I started fitting 224 small Neo magnets around the inside of a stripped F&P rotor. This will be the standard 3 Phase rotor configuration for a dual stator/rotor mill I am building. A very messy and time consuming task,as I had to clean all the magnets of their polyester resin from a previous failed attempt.. Sore fingers also,lining them up on a slight angle to reduce cogging . Bruce  Bushboy |
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martinjsto Senior Member  Joined: 09/10/2007 Location: AustraliaPosts: 149 |
looking good so far, how did you remove the original ceramic magnets? i have some magnets comming soon, was thinking of using a brake drum, is that the old steel bands still in place? im getting 6mm magnets it looks like you have 2, 3mm together so should get similar results. interesting to see results martin free power for all McAlinden WA |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi Martin,, crack the first ceramic magnet out with a 6mm chisel and hammer carefully.. The rest should pop out by levering them off the steel band --the glue is not so strong.. Then clean up any bits and pieces of plastic that will get in the way ,finally a brisk sandpapering around the inside .. I don't glue mine in ,,they stick very firmly anyhow. Leave the steel bands like they are. I think they are 12mm X 6mm X 3 mm Neo's.. take it very easy,,it's utmost important that you get the poles correct--udderwise,,it don't workie !! Bruce Bushboy |
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| martinjsto Senior Member Joined: 09/10/2007 Location: AustraliaPosts: 149 |
ok got the old magnets off ok, new ones arived today there 6mm * 12mm * 25mm neo, very strong magnets tryed to locate on rotor but the forces were pushing them apart so i couldnot get the spacing i required. might need to glue as i go. what about the wall thickness, i have read that these original hubs will flex out of shape under the load of the neo's. will you strenghthen it? also i was wondering whether more steel lamination is required becouse of the stronger magnets? from a electronic point of view not strength. you mentioned an angle on the magnets. to reduce cogging i guess, how much do you think i should allow. sory for some simple questions but this is the first neo conversion i have done and i want to get it right, better to learn form other peoples experience i reccon. you seem to use 4 magnets for every 1 that i am using is there a reason or is that becouse you are re-using some old ones you have salvaged? thanks for youe help bruce, will be interesting to compare results when there up and running martin free power for all McAlinden WA |
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| martinjsto Senior Member Joined: 09/10/2007 Location: AustraliaPosts: 149 |
 [IMG]free power for all McAlinden WA |
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Storm Regular Member  Joined: 12/09/2005 Location: AustraliaPosts: 43 |
Cut some strips on wood or alu the width you want to space the magnets should help in the placement. |
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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Looking at these neo conversions makes me wonder if you guys did consider fabricating suitable spacers (out of PVC perhaps) to keep the magnets equally spaced and perfectly aligned. Was this a case for the too hard basket  ?
Also, I notice one rotor shows small magnets stacked 2X on top of each other and also next to each other. Does this create a magnet 4 times as strong? I would be interested to hear from somebody to whom permanent magnets are very familiar what the result of PM stacking is. Intuition and playing with small disk magnets here tells me that a vertical stack has not the (lifting) power of stack # times the individual magnet. Surely there would be some losses at the meeting surfaces? Klaus Klaus |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi Crew,, have used spacers before this mod,,but ,for me ,it dosen't seem too necessary , as I place a piece of wood(chopstick) adjacent to the finished magnet as I sit the new one down . Ok, you get some that wander, but not many. stacking,,well,thats what I've got many small ones,,(they were cheap). Dunno about the power Etc. Just know these are "Bloody powerfull ! ". Strength of rotor case-- yeah,is a bit of flex,may back it with a 6mm Aluminium disc ,,we'll see. Just discovered I'm 2 or 3 magnets short- "Bummer" another trip to the big smoke to scrounge a few.. have fun Bruce Bushboy |
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| martinjsto Senior Member Joined: 09/10/2007 Location: AustraliaPosts: 149 |
sory for the 1st lot of pics guys, glen could you edit for me, forgot to enter after 1st pic. ta i think spacers would be a good idear to ensure accurate alignment. i will do a lot of test runs b4 actual resining in place magnets cost me 100 dollard inc delivery for 50 not too bad but i dont want to stuff them by rushing. i also have a 100 series rotor and stator, i was wondering if the rotor is stronger as it uses individual magnets. see pics from my reading on neo's having 2 on top of each other increases power by aprox 60 to 70% dosnot double it, but you use what you can get, i have thought of the magnets found in old hard drives, they are 3mm thick with north and south on the one side, you will need to break them in half and twist one half over to align the norths and souths. but there very good, easy to get neo magnets. bummer about the quantity bruce always the way  , i ordered 2 extra just in case lol
martin free power for all McAlinden WA |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
Hi,, Martin ,, I tried removing those individual magnets in the 100 series rotor-- for me it was a failure-they are somehow bonded in very differently from the block ceramics and are also impossible to get all of the material off the steel backing,,if I remember ! There is a rotor that I imagined to be stronger--a brownish fibre composite rotor--only have ever scrounged one in my 20 or so "finds". Look for it -twisting by hand ,it seems to be stronger-dunno !!. Frenergy.com.au are at Ormeo southside of Brisbane ,, ph 0409 533626 I'm going to call them and ask if I can go there and pick up the order--dunno,,some of these joints are mail houses-u place the order ,they forward it on and get the commission-freight usually costs an arm and a leg !! stop rants Bruce Bushboy |
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imsmooth Senior Member Joined: 07/02/2008 Location: United StatesPosts: 214 |
Hello everyone. My first post here. I have a F&P that I have recently setup for a wind generator in the future. Right now I am revising it for more output. I am getting a second hub to convert to neo magnets. I have read through the forum and want to get a summary opinion. 1. Right now I have 56 25mm x 10mm x 3mm N42 magnets. Will these significantly increase the wattage? If not, I have a Chinese company that can fabricate any size and grade I want. I was going to get 30mm x 10mm x 5mm, unless someone here thinks a different dimension is better. 2. What is the best angle. I have seen a few posts here about different slants. 10 degrees sound good? 3. What size rotor works best for the 60 series with neos? I was going to use 8' - 10' as this seemed to approximate the output. |
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Gizmo Admin Group  Joined: 05/06/2004 Location: AustraliaPosts: 5119 |
Hi imsmooth, welcome to the site I havn't done a neo conversion myself ( will get there one day ), but I can help with the turbine size. It depends a lot on your wind conditions. For a standard hub ( ceramic magnets ), a 6 to 8 foot blade works well. The Neo's will almost double your output power and lower your cut in speed, so a larger turbine ( 8 to 10 foot ) will suit. Glenn The best time to plant a tree was twenty years ago, the second best time is right now. JAQ |
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| martinjsto Senior Member Joined: 09/10/2007 Location: AustraliaPosts: 149 |
hi all and welcome imsmooth, i havnot done alot the last few days, just started to make a jig to align and position the magnets. i tryed to place them using spaces but didnt have much luck, i calculated i needed spacers of 1.91mm wide for a finish inside diameter of 249mm as per original. the jig will be made from alluminium, and should position magnets exactly as per original new 7 phase rotor but with the slight angle and should also provide the well for the resin fill, does anyone know if the angle is better aimed in direction of rotation or against? i use 25mm * 12.5mm * 6mm magnets i chose them becouse the size reflects the original ones although 30mm lond is more close, also once you remove the old ceramic ones you will notice there 6mm thick so i should be back to the same inside diameter. i will post pics once i have finished cutting out the spaces for magnets. i got the brown composit rotor today, I happend to find one in the local bulk refuge (what luck) i will test soon for strengh but it does look more structualy sound. good work people martin free power for all McAlinden WA |
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| martinjsto Senior Member Joined: 09/10/2007 Location: AustraliaPosts: 149 |
imsmooth, i just realised your the imsmooth from ebay. im martin110263 nice to see you here and the best of luck with the conversion, this is my first neo conversion but i have 2, 7 phase units working on my farm. you will find the people here very informative and helpful martin free power for all McAlinden WA |
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| imsmooth Senior Member Joined: 07/02/2008 Location: United StatesPosts: 214 |
Hello Martin. Thanks again. I'm getting the second hub from someone in the USA. This is what I've done so far as far as a craddle for testing the generator at this link here Once I strip the hub I will order the magnets. I'm thinking of getting N45 29x11x5. If others are interested I can have a larger number made if you are will to pay the shipping and cost of fabrication. I will then have to figure out how to make a spacer. I'm thinking of just using some firm cardboard. |
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vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
Hi Bruce Looks like one pole was harder to remove if thats BLOOD i'm seeing.Carry on and take it easy.Kiddin Jmsmooth You found your f&p home and welcome aboard.Maybe use playing cards for spacing.I use small blocks of dimensional lumber but mine are farther apart.56pl with 32in diameter. Mark |
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| vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
Gizmo this posting got pregnant on my screen.Is that normal or my machine? |
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| brucedownunder2 Guru Joined: 14/09/2005 Location: AustraliaPosts: 1548 |
No,, thats not Blood,,it's Ilda's fingernail paint --I dabed a spot of red on one set of magnets then a black felt pen mark on the adjacent row ,,all around all of the rows.. that way you can make absolutely sure of the polarity ,north,south,nort , south Etc.. I f you get it wrong and resin them in ,,it's a bugger of a job fixing them ,,and you'll know,,it won't work !!. The chopstick idea works well for a temporary spacer--What I did was divide the inner surface equal to a ceramic tile and mark on the plastic ,,that way u can be fairly sure of being within a half mm or so ..Then when you are finished inserting all the magnets ,,eyeball the finished job to make sure you have all those spaces between the magnets as near equal as possible,,check the poles them gaffa tape the inside to form a dam for the resin. Warning--- Use the cloth inpregnated gaffa tape--ordinary plastic tape will melt--believe me -- Bruce Bushboy |
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| vawtman Senior Member Joined: 14/09/2006 Location: United StatesPosts: 146 |
What i do is hold the magnet between my index fingers has i go around the rotor to test. If i got caught using my wifes stuff.Not good  |
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herbnz Senior Member Joined: 18/02/2007 Location: New ZealandPosts: 258 |
Hi has any bench testing been done on these conversions ? From testing standard rotors I see the stator poles are saturated at no load so I believe the stronger magnets would be working with a air core at no load. The big differance would be the point where current limit occurs. Also is the oportunity taken to true the rotors out of round up I have measured .9mm on some ? Herb |
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