bldc design from scratch

Hi,

could someone guide me through the steps of how I would go about designing a bldc motor, knowing only the following requirements;

a) Power 300W
b) voltage 24V
c) Torque 40 Nm
d) RPM 180
e) Max external dia = 254mm
f) Max length = 90 mm

So now I need to know;
1) How many poles do I need? and why?
2) How many teeth? and why?
3) How many windings? and why?
4) Of what diameter wire? and why?
5) What dimension magnets? and why?

Would much appreciate if you can get me started.
I'm sure I can take it from there
Thanks

Sunil

I not trying to run you off, but I don't think too many folks on this forum are building motors from scratch. Ron Van Sommeren has posted many good links to sites that may give you the info you request. Just search on his name and follow the links.

I would love to see a build thread on your motor when you start fabrication.

Bubba

gobrushless.com can supply stators which IMO, is the hardest part.

This would be a good place to start. But, it seems like you want
a low power,low rpm, large high torque motor... So it may not be, because
the largest stator they have is 65mm...which would yield ~80mm bell size outrunner...

Do you want an inrunner or outrunner?

I'll defer to the experts here, but very roughly that sounds similar in design to the existing hub motors, but with a lot more poles.

Maybe these will give some clues, high torque motors for direct drive helicopters:

• http://www.rcgroups.com/forums/showthread.php?t=587208
• translate.google.com...www.powercroco.de/helidirektantriebe.html
• http://endless-sphere.com/forums/viewtopic.php?f=28&t=12183

Vriendelijke groeten Ron
• brushless motor building tips & tricks • diy brushless motor discussion group
• Drive Calculator download & discussion group • int. electric fly-in, Nijmegen, the Netherlands

Parallel discussion, notably Louis Fourdan's answer:
http://groups.yahoo.com/group/lrk-torquemax/messages/12305?xm=1&m=s&l=1

Vriendelijke groeten Ron

Torque calculations using FEMM (http://www.femm.com)
http://tech.groups.yahoo.com/group/Femm/messages/1687?xm=1&m=p&tidx=1

Prettig weekend Ron