this would need a variable frequency control box if run from battery/inverter ?

Yes. If you want to give it a try, there is some good info in the video below. That guy has built roadworthy DIY electric cars in the past but he gave up trying to make this concept work. There are a few points on which I think he could have improved his chances of success but didn't. You might succeed where he failed.

He is using an automotive alternator but the concept is the same. One difference is that an automotive alternator which is three phase, and yours is (I assume) only single phase. Three phase is much better for motor control applications and there are plenty of controllers out there for 3 phase (not three phase with rotor excitation regulator tho). There is almost nothing for single phase.

One thing I think he needed to try but didn't, is adjusting the rotor current in response to load. He just fed it a straight 12V and think that was part of the problem.

 

can the unit be rewound to avoid fixed rpm runing

no. The synchronous nature of it is its defining characteristic. Totally different animal from an asynchronous (induction) motor. It's like "can I change my tires and turn my car into a bicycle."

 

2 phase if 240 v as two 120v lines ?

 

2 phase if 240 v as two 120v lines ?

Nope

 

how as each side is a phase at 240v USA system standard or two 120 lines OUT OF PHASE

 

BTW LIKE THE CART GUY
wonder if the car battery at junk yard price is lower then buying cells and building one

 

how as each side is a phase at 240v USA system standard or two 120 lines OUT OF PHASE

This is technically called a split single phase. Otherwise known as a center tapped transformer.

To quote Wikipedia;
Two-phase electrical power was an early 20th-century polyphasealternating current electric power distribution system. Two circuits were used, with voltage phases differing by one-quarter of a cycle, 90°.

 

how as each side is a phase at 240v USA system standard or two 120 lines OUT OF PHASE

I like to explain single phase, two phase, and 3 phase, with a steam locomotive analogy.

Scenario #1:
You have a locomotive with a single cylinder and a single driven wheel. Depending on the orientation of the wheel when parked, you may or may not be able to get the thing moving again under its own power. It would be able to chooch all day long with a nudge to get it started, but without that nudge it will probably be stuck. If the piston is fully extended or fully retracted (or anywhere close to either extreme) at rest, then there is no hope. For the best possible odds, it should be parked with the cylinder at mid-point in its stroke so that the very first pressure applied to the piston results in a 90 degree turn of the wheel, which hopefully will be carried past top dead center or bottom dead center by inertia, and once past that center point the wheel can once again be affected by the piston. And again, again, a chain reaction with two points of vulnerability in every rotation. This is analogous to single phase electric motors.

Scenario #2:
You take your single-cylinder locomotive and add a 2nd cylinder to the other side of the locomotive, driving a wheel on that side. Your two driven wheels are clocked 90 degrees apart from each other and connected via a live axle so that they always stay 90 degrees out of phase with each other. Now it doesn't matter how you park it. If you park it with one cylinder fully extended or fully retracted, then the other one will be at mid-stroke. This locomotive will always be able to get going on its own. This is analogous to a two-phase electric motor.

Two-phase motors do exist but only very old ones and only in very specific industrial sectors in a couple of tiny isolated pockets of the country where the electric grid is older than the standards we now abide by. Probably 99 out of 100 Americans alive today have never seen a 2 phase motor and most of those who have, didn't know it was 2-phase. It is extremely rare. We don't use it because it requires 4 wires; 2 for each phase.

Scenario #3:
The analogy starts to stretch a little here but see if you can follow. Take your two-cylinder locomotive from above and instead of clocking the driven wheels 90 degrees apart, clock them 120 degrees apart. Then add a 3rd piston underneath the train on its centerline, driving an arm that is inserted in the axle like a crankshaft, and the arm is clocked 120 degrees from both wheels. Now, in any given position of the wheel you can have two different pistons acting on it. You guessed it, this is 3-phase. This has all the benefits of 2-phase with the added benefit of requiring only 3 wires.

Scenario #4:
Rewind to Scenario #1. We have a single cylinder, connected to a single point on a single driven wheel. Now add a second cylinder to the same point on the same driven wheel. The original one was mounted from the back of the locomotive going forward to the driven wheel, and this new one can be mounted to the front of the locomotive, going aft to the driven wheel. They are in-line with each other. When one is fully extended the other is fully retracted. There is 0 degrees of phase separation between them. They are a single "axis" or a single "phase," just split in two. They have no advantage over scenario #1; you could get the same effect by just using a larger piston in scenario #1. This is analogous to the single split phase power in North America. It is single phase, not 2 phase. It is a single phase, just split in half.

The reasons why it is hard to start the locomotive in scenarios 1 & 4 are physically the exact reasons why it is hard to start a single phase electric motor. That is why single phase motors require a capacitor and a start winding. The capacitor phase-shifts the incoming voltage creating a quasi-second-phase into the start winding which clocked physically some number of degrees apart from the main winding, to provide a temporary nudge to get the motor running, then it can chooch all day long.

This makes a single phase motor (synchronous or otherwise) very hard to control with an electronic controller. It literally does matter what physical orientation the shaft is in when you start sending AC voltage to it. Just like the single cylinder locomotive, if it is anywhere near top or bottom dead center when you try to start it, it goes precisely nowhere (or hums obnoxiously followed by smoke). This is why 3 phase is king, and requires no capacitors. This is why motor controllers are made almost exclusively for 3 phase motors. This is one of many reasons why your single (split but still single)-phase generator head makes the worst possible choice of motor for this (or any) AC motor application.

 

The very first thing to do is see if the found power generator package functions. Some of the power generator systems use an inverter and electronic engine controls so they are only producing the required power, which saves a lot of fuel. It also means that the actual power generation is variable voltage feeding some version of an inverter. THAT sort of system would be a very serious challenge to run as a motor. And even at 100% efficiency it would put a huge draw on the battery system. My experience on a sailboat with a small gas engine was that it was used to get away from the docking harbor and away from close proximity to other boats. Then the engine was shut down and sailing began.

So the package acquired might be OK tp power a motor for exiting the marina, Maybe

 

have owned borrowed used many different 1 banger gas gens
boats and post hurricane
this is a cheap older style china copy as sold in the usa
common looking with china copy honda looking gas motor
nothing fancy or inverted suspected maybe 10 years old or more

 

OK, I was thinking about current production Honda generator packages. The one in this discussion is much different, it seems. If the generator has only slip rings then it could only possibly, be run as a synchronous motor, not suitable for marine drive applications.
So the best choice is to make it run and exchange it for repairs on the diesel engine. Barter can be useful.

 

diesel repair at this point would involve melting original to recast the iron block to start from that as it was GONE

 

No vehicle junkyards where you live? A diesel car or truck engine could be added to your boat easier than trying to make a motor out of your generator.

 

If the generator has only slip rings

Were talking about an alternator not a generator. Alternators use some form of slip rings to power the rotor. Some slip rings are on the shaft and some are mounted perpendicular to the shaft on the end of the rotor, but they still need slip rings, without them there is no way to power the rotor. Even the inverter ones have them.

 

Are start / run capacitors out of the question at that power level?

 

my understanding is a generator has a magnet field and produces DC current
an alternator has only coils for eltro magnets and produces AC that in a car is reXed to DC

and this gen I have is not really ether as both can be converted to a motor and this unit is a female dog for that

btw ideas for a cheap lite 10 hp el unit to spin a prop ?

 

Are start / run capacitors out of the question at that power level?

I'm pretty sure I've seen 10HP single phase motors on stationary agricultural equipment but that is fixed-speed application. I think the capacitor would need to match the applied frequency so for variable speed would need to be variable. Or fixed for a certain frequency that ensures reliable starting from very low Hz and running very inefficiently at constant speed below which the centrifugal switch disconnects it. Plus there is no start winding on a generator head to connect one to.

 

No vehicle junkyards where you live? A diesel car or truck engine could be added to your boat easier than trying to make a motor out of your generator.

I never see a 10 hp car or truck diesel most are too big too heavy and cost far too much used 5k way up
have seen ads for air cooled china made B&S or honda sized diesel units but never seen one here

 

btw ideas for a cheap lite 10 hp el unit to spin a prop ?

Alright now we are getting somewhere. Check out this guy's videos. His deal is a bit different than yours; he is focused on long range, so more battery and less motor than what I assume you are after. But he posts very detailed data relevant to electric boating, which I think you will find helpful.

I have done none of my own research into electric outboard motors but my experience with subsea/ROV electric motors would lead me to start with a brushless motor (probably BLDC but not necessarily BLDC, just anything without brushes incl induction and servo motors) that comes in an IP65 format and can be filled with mineral oil. I don't want to get any more specific than that because I don't know your speed or torque requirements. Depending on the propellers/impellers you use, you might need high speed/low torque or low speed/high torque or something in between. I would hate to point you in the wrong direction. Do you have any information on this already? Perhaps you know the shaft RPM of an existing 10HP outboard from which you might rob a propeller?

 

prop on the boat was for a sub 3k rpm diesel reduced by about 1/2 so 1500 rpm at 10 hp shaft 1''
prop can be swapped or bent by a shop to change rpm needed some [bronze]
only old fashion shaft props will work not outboard as most are far high rpm 4 to 8k with odd hubs

problem with new tec bushless is very few used or surplus units
very small from power tools or too big from el car forklift ect
but few and no cheap ones in my 10 hp range

thought of and rejected ganged power tools like saws or a bunch of car starters
or golfcart starter/gens at 1 hp each from gas carts but need too many

have a golf cart el motor rated 3 hp 48v but endbell bit is part of a carts gear train and bearing
and size style shaft fails to match other el a/c motors so like my gen unit is useless lacking an endbell and bearing