I doubt you will find a 12VDC motor over 1HP. www.surpluscCenter.com has
2HP 24VDC motors that draw 72 amps ad full load for $200. You might also
look at old automotive starter motors. Not sure of the HP but they are very
popular for barstool racing in the 12V classes.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Michael" wrote in message
...
Hi,

I'm building a model submarine it will have a displacement of around 500kg
and a length of 4m.
Having worked out a rough idea as to the size of the motor required, 3hp.
I'm now looking for suggestions. Sites like technobots don't stock ones
large enough and so I'm struggling to find an answer.
Then there is the matter of how to control the speed. Ideally I'd like
proportional control.

So, does anyone know where I can find a large enough motor, ideally with
the
electronics to control it? The onboard power will be provided for by two
12V
batteries,
of which the AH is still undecided.

Thanks

Michael