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Subject: Re: [Homebrew_PCBs] Re: cutting boards - methods?

From: DJ Delorie <dj@...>
Date: 2007-01-22

"lcdpublishing" <lcdpublishing@...> writes:
> Not sure what a brushless motor is, but if it can be machined, I can
> probably make one :-) Any links to information about making them?

Don't know about links, but some background info:

I know of two types of brushless motors. One has a permanent magnet
on the rotator, with three pairs of coils around it. Applying out of
phase sine waves to the coils creates directional magnetic torque.
This is very common in large AC-drive motors, esp when three-phase
power is available.

The second type is a variable reluctance motor. The rotator is just
ferrous metal, with N poles. There are N-1 coils, so turning them on
in sequence drives the rotator in the other direction as it tries to
align its poles to the new fields. This is common in stepper motors,
but can be used for high-power motors as well.

Aside from the mechanisms for generating torque, the contruction of
these are similar.

The Nova DVR lathe uses the second type of motor, see
http://www.teknatool.com/products/Lathes/DVR/Nova%20_DVR.htm

http://www.cs.uiowa.edu/~jones/step/types.html