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Larry W4CSC
 
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Default "get home" electric motor coupling to prop shaft?

On 16 Nov 2003 01:00:32 GMT, (BOEING377) wrote:

If you are going to have AC power
available, why not ditch the DC power nonsense and go with a variable
AC motor speed control and a suitable AC drive motor straight off the
alternator, making it all more efficient. There are some whopping
variable-speed AC motors available from electrical supply places.
746W/horsepower, you'd have about 6 hp off a 5KW genset at full
throttle. It'd be a long road home.....

A very old 6-71 has just been broken in if someone changed its oil
when they were supposed to. Is it hard to start in its condition?

Yes, hard to start unless preheated or shot with ether. Runs OK once started.
OLD... ex navy 1944. Estimate over 20,000 hrs w/o OH. Will have to consider AC
drive motor idea. Doesnt speed control involve a $$$ variable freq inverter?
Or are you talking about brush type motors?


Any drive motor project to run this boat from the AC power plant is
going to be expensive, AC controls or DC controls.

Thanks for info on the engine. Back in the 1960's I inherited a 6-71
driving a big DC generator that used to power a gun mount from Korean
War era aboard a destroyer tender. A refit put a helo deck for the
biggest boondoggle in Navy history, the DASH (Drone AntiSubmarine
Helicopter) where the gun mount was and the genset was refitted to
power a big MG set to convert the DC into 440VAC, 3-phase to power my
calibration laboratory (PMEL) just forward of the generator
compartment, on the main deck. When I inherited it, it had a mere
54,000+ hours on it, without overhaul, and we ran it 24/7 any time the
ship left the dock power supply, or the dock got unstable. It never
broke down and there were no history records of it breaking, either,
that I had. We did the maintenance, religiously, and it just kept
turning those big coils in the open-faced generator. Great engines.

Of course, we had power when the rest of the ship was mostly
dark....(c;



Larry W4CSC

"Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!"