Drive system for LARGE Boat
 

I am new here, and need advise badly ref my first LARGE boat project. Basically I need some advise for a drive system for my project. I wish to keep it simple yet functional. Here is my project:

Total boat length is right at 9.6 foot yes foot.
Width is 3 feet
height from keel is 20 inches

I am doing a single long piece keel with spaced bulkheads at 12 inch intervels which are open. Hull will be thin wood sheathing with fiberglass over it to make a good sturdy hull and keep wood weight down.

My plan is to power it with an electric propulsion setup using a 12 Volt Motorcycle battery. So my question becomes this:

1. How big of a prop will I need, and how many??? Will a pair of 3 inch sized props work? and if so do they make them that big and where do you find them.

2. What kind of electric motors would be needed, and what size diameter drive shaft.

3. Speed Controlers ?????

I have a weedeater motor option available and already have a good running engine, but I would prefer electric as my number one choice for obvious reasons.

If anyone can give some words of advise I would appreciate experience and your wisdom on this. Feel free to email me at: [email protected]

Thanks

Tom S

RE: Drive system for LARGE Boat
 

With something this big you might want to take a look at trolling motors for power. I've seen larger R/C boats, up to 14 feet in length. One was powered by power seat motors. Junkyards would be a good place to look for other electric motors. What they used for ESC's, I don't know. I would use something larger for a battery also like a deep-cycle battery. They are heavy at around 65-70 pounds but you're going to need the ballast.
Octura has some big props.
What type of hull are you planning on building? Are you looking for speed or a scale type of boat?

RE: Drive system for LARGE Boat
 

[8D]
Hi -- Not to long ago, while searching the net for model boat info, found this. A guy in England was useing auto (car) starter motors as a electric drive sys. for a large model boat...BUT!, you'll need a bigger battery than a motor cycle battery. With that SIZE boat a big heavy battery, or two, should be no problem. I beleive he used British Ford starter motors, but I'm not 100% sure.
BOBJAY

RE: Drive system for LARGE Boat
 

Some years ago a German boater was building a 4m model of the Bismark, if memory serves me well.

It had three or four propshafts, each powered by two belt reduced Bosch startermotors, that's eight(8!) motors...

The motors were controlled by custom built controllers, and a massive amount of deep cycle batteries.
With all that weight the hull still needed waterballast to reach the intended waterline.
It sailed just like the real thing.

If you're interested, I can try to dig up the article.

Regards, Jan.

RE: Drive system for LARGE Boat
 

if you want to make it gas try an get an old jet drive form a jet ski, an put a rotax engine in that thing. Your r/c boat is as big as my jet ski. lol

RE: Drive system for LARGE Boat
 

Take a look at this. It is an older article but is very informative.

[link=http://www.catfishin.net/damboat.html]Dam Boat[/link]

RE: Drive system for LARGE Boat
 

I have a 24 volt electric mower motor that would be great for that!! It has enough torque to more than handle the boat and you could put 2 12 volt batteries together to get the 24 volts.

Just a thought.

regards Curt

RE: Drive system for LARGE Boat
 

I have seen a number of electric bicycle motors and speed controls on Ebay that might be adaptable for your boat. Usually these motors run on 24 volts ( two 12 volt batteries in series)