Brushless motors Pt2

Hi Folks, one for the techies on brushless motrors, just stripped down two largish video player motors to use the cans for
building brushless motors and found they both had lovely big 30-plate six segment armatures in them so stripped these down and knocked the shafts out to use again, the windings were very fine wire and no use so I removed it all and cut the core down to three blocks of nine plates. Would these be of any use or will a motor built with them be too lumpy with about 15 magnets around the outer? I have plenty of magnets so thats no problem, was thinking of using two stators but would this work satisfactorily?,
regards, Terry
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Terence Lynock (MSW) wrote:

I think so..but take this question here.. http://www.rcgroups.com/electric-motor-design-and-construction-361 / for far better advice..six segments is a bit low for a torque motor, but should make a speed motor all right. Number of magnets depends on how you wind it.
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Goedendag Terry,
The number of magnetpoles must be a multiple of two. Furthermore, the choice in number of magnets is restricted by the number of statorteeth. For six statorteeth you can use 8magnetpoles (for high Kt =torque/Ampre) or 4 magnetpoles (high Kv = rpm/Volt). In both cases the winding diagram is ABCABC. Winding diagram table: www.powercroco.de -> tools & links -> Kombinationstabelle (The powercroco site is the 'bible', use http://babelfish.altavista.com for automatic translation, and a good laugh, it's far from perfect but it will do for techno-geak-speak, anyway lots of pictures on the powercroco site that are very instructive and speak for themselves) What's the thickness of a single statorplate?
As the Natural philanderer wrote, you're better of in the 'motor design and construction' subforum at www.rcgroups.com , lots of diy motor builders: http://www.rcgroups.com/electric-motor-design-and-construction-361 / Just start a new thread and post some pictures and dimensions of your stator.
Help and discussion group, 'owned' by yours truly: http://www.yahoogroups.com/group/lrk-torquemax
Do-it-yourself motor homepages, manuals/tutorials, checks and tests in this motor builders tips and tricks thread. The checks and tests MAY SAVE YOU FROM FRYING your controller or motor. Thread is active, bookmark it for future reference and subscribe to it: <http://www.rcgroups.com/forums/showthread.php?t $0993> (sticky thread, at top of subforum)
Fellow Brit builders: http://www.rcmf.co.uk/4um/index.php?board=4.0
Excellent motor building articles by Brian Mulder, a MUST read, will prevent you from asking a lot of questions :-) http://www.southernsoaringclub.org.za / -> Articles by SouthEasterners. -> Electric Motors - part 1-5
Also www.solcon.nl/gjkool www.bavaria-direct.co.za www.torcman.de/peterslrk/index_eng.html
Neodymium magnet sources: www.engconcepts.net (a.ka. Mr. George) www.supermagnete.com www.aircraft-world.com www.croco-power.de (a.k.a. die Sandra)
List of manufacturers/suppliers: motor kits, turned parts, shaft, stators & magnets: http://www.rclineforum.de/forum/board.php?boardid )
Vriendelijke groeten ;-) Ron van Sommeren 14th.int. electric fly-in, Aug.26, Nijmegen, Netherlands http://home.hetnet.nl/~ronvans /

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Hi Ron and co, a lot of info to be gone through so have some reading to do, on the torcman.de site there is a motor shown using just six teeth out of the twelve on the stator with fourteen magnets, wonder if my six tooth stators would work using this design? answer to an earlier question Ron the salvaged stators I have are now nine plate with a plate thickness of 0.55 mm approx give or take a thou or two so are all within the 4.5 to 5mm total thickness range,
regards, Terry
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Goedendag Terence,
A motor with only 6 out of 12 teeth wound is not the same as a 6teeth motor with all teeth wound, they have to have different winding diagrams and the number of magnetpoles differs too. The first uses 10 or 14 magnets and uses the lrk-winding diagram (this diy motor design started all this, read the (English) Elektro Modell articles at the bottom of the Torcman page), the second has 4 or 8 magnetpoles and uses the cd-rom style winding diagram.
The plates are a bit thickish (higher eddy-currents), but or probably of very good quality. You could also buy a kit of course, they generally come with a good manual.
If I where you I would start with this very good introduction. http://www.southernsoaringclub.org.za / -> Articles by SouthEasterners. -> Electric Motors - part 1-5
Vriendelijke groeten ;-) Ron van Sommeren 14th.int. electric fly-in, Aug.26, Nijmegen, Netherlands http://home.hetnet.nl/~ronvans /

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from "Ron van Sommeren" <ron.van.sommeren_curly_thingy_hetnet.nl> contains these words:

Hi Ron, the stators I salvaged have six full teeth as others but a full depth bar between them, almost like another tooth without the crosspiece on the top, a sort of I T I T I T I arrangement, not sure what this could be used for but it may be fun experimenting,
regards, Terry
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Goedendag Terry,
Wind them LRK style: leave the intermediate posts empty, wind the 'hammerheaded' teeth.
Vriendelijke groeten ;-) Ron van Sommeren 14th.int. electric fly-in, Aug.26, Nijmegen, Netherlands http://home.hetnet.nl/~ronvans /

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