Alan B. Pearce wrote:
>
> >However, I think that large size steppers could be promoted to submarine
> >thrusters. They have the necessary parts in them and the stator could be
> >potted. They could be oil filled as above or open to the sea.
>
> How about using a Brushless DC Fan as used in PC Power Supplies? seal the
> electronics unit and you already have a set of propeller blades on the
> moving bit.


That is one of the cleverest ideas yet, especially
if filled with waterproof grease or the like.
Those fans are pretty weak but you see more and
more brushless fans (DC) of higher power ratings,
and one might be an ideal drop-in for a small sub.
-Roman

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.