Brushless motors Pt2

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Terence Lynock (MSW) - 24 Jan 2007 12:18 GMT

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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The Natural Philosopher - 24 Jan 2007 13:45 GMT

> Hi Folks,
> one for the techies on brushless motrors, just
[quoted text clipped - 10 lines]
> regards, Terry
>

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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Ron van Sommeren - 24 Jan 2007 17:42 GMT

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/Ampère) 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 [b]homepages, manuals/tutorials, checks and tests[/b]
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=240993> (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=29

Vriendelijke groeten ;-) Ron van Sommeren
14th.int. electric fly-in, Aug.26, Nijmegen, Netherlands
http://home.hetnet.nl/~ronvans/

> Hi Folks,
> one for the techies on brushless motrors, just
[quoted text clipped - 9 lines]
>
> regards, Terry

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Terence Lynock (MSW) - 24 Jan 2007 22:23 GMT

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

Reply to this Message

Ron van Sommeren - 25 Jan 2007 20:27 GMT

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/

> Hi Ron and co,
> a lot of info to be gone through so have
[quoted text clipped - 6 lines]
>
> regards, Terry

Reply to this Message

Terence Lynock (CSM) - 25 Jan 2007 23:47 GMT

The message <45b912c3$0$16884$ba620dc5@text.nova.planet.nl>
from "Ron van Sommeren" <ron.van.sommeren_curly_thingy_hetnet.nl>
contains these words:

> 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.

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

Reply to this Message

Ron van Sommeren - 29 Jan 2007 17:27 GMT

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/

> Hi Ron,
> the stators I salvaged have six full teeth as others but
[quoted text clipped - 3 lines]
>
> regards, Terry

Reply to this Message

Model Forum / Radio Controlled / Air Models / January 2007

Brushless motors Pt2