Richard van den Berg wrote:

Regular outboards do have a fair weight/hp compared to e-motor and
batteries. The only thin you have to worry about is fuel. Or how did you
plan to fill your batteries?

Oh, I was planning to have a diesel engine (and a generator) running most of
the time to provide the electricity. The idea was to be able to place the
generator engine where I wanted it, and the propelller(s) and the driving
engine where they would be most useful. Instead of a solid shaft, I would
have flexible cables in between. I could run it on the batteries for a
minutes, if I needed extra manouvering, but in most cases, the power would
come from the generator. Also, I was hoping that the electric propulsion
would be smaller and lighter, so it would be easier to lift out of the
water when going by sail...

- Heikki

On Sat, 15 Dec 2007 09:50:00 +0100, Heikki wrote:

John C. wrote:

Run it as a generator and use it to charge an oversized bank of batteries.
With an electric motor you will gain variable speed and direction without
have an engineering nightmare.

I have been speculating about a diesel-electric propulsion for a smallish
sailboat. Does anyone have links to, or experience with, small electric
motors that are suitable for continuous use - most of my googling finds bow
thrusters and other extra machinery.

There are electric fishing motors, in the one horsepower or less
class. Maybe enough power for an under twenty foot boat. Not good on a
windy day.

I am thinking of a fairly small engine, say 5-10 Hp, to be used mostly in
manouvering in and out of marinas, and occasionally coming home from a calm
sea. Would it make sense to mount the whole engine on the transom-hung
rudder? That way it could turn with the rudder, and give good steering in
both directions. When not in use, it could be lifted out of the water, so I
could use a decent size of propeller for it.

There is the tried and true outboard motor. Hanging stuff on the
rudder sounds like a poor approach to me. Not to mention ugly.

Would anyone care to shoot the idea down before I get too attached to it.

Shouldn't be too hard.

Casady

Look into golf cart motors. Consider duty cycle and run times with respect
to motor choice and battery bank size. Larger engines can be found in the
fork truck industry. Both the golf cart and fork truck would provide speed
and direction controls as well as basic mounting design. Your small diesel
generator may need to run much longer than your motor and or you will
require dockside recharging and use the diesel as back and top-off while at
sea. Keeping the generator output close to the energy needs of the motor
will increase the overall efficiency of the system. It would be useless to
require 4 hours of charging to produce the energy needed for 15 minutes of
motoring unless the battery bank was large enough to carry reserve energy in
far excess of your typical needs. The primary charge would then come from
dockside sources and your generator would be always on stand by.

There is a lot of info on the net about hybrid electric craft. You just need
to apply the information to your specific application.




"Richard Casady" wrote in message
...
On Sat, 15 Dec 2007 09:50:00 +0100, Heikki wrote:

John C. wrote:

Run it as a generator and use it to charge an oversized bank of
batteries.
With an electric motor you will gain variable speed and direction
without
have an engineering nightmare.

I have been speculating about a diesel-electric propulsion for a smallish
sailboat. Does anyone have links to, or experience with, small electric
motors that are suitable for continuous use - most of my googling finds
bow
thrusters and other extra machinery.

There are electric fishing motors, in the one horsepower or less
class. Maybe enough power for an under twenty foot boat. Not good on a
windy day.

I am thinking of a fairly small engine, say 5-10 Hp, to be used mostly in
manouvering in and out of marinas, and occasionally coming home from a
calm
sea. Would it make sense to mount the whole engine on the transom-hung
rudder? That way it could turn with the rudder, and give good steering in
both directions. When not in use, it could be lifted out of the water, so
I
could use a decent size of propeller for it.

There is the tried and true outboard motor. Hanging stuff on the
rudder sounds like a poor approach to me. Not to mention ugly.

Would anyone care to shoot the idea down before I get too attached to it.

Shouldn't be too hard.

Casady

wrote in news:df918b70-350c-4fa7-80a1-
:

Somehow I found this site:

http://members.aol.com/westernstar66/indianlisters.html

that lists a 20 hp diesel for $3250, a real bargain for a new
engine
compared to most diesels for boats. These are low rpm diesels
that
can run on vegetable oil and are very efficient.

So, what would you do for a transmission? Maybe you could use
a belt
with an idler pulley that was lever controlled. Tension on the
idler
pulley would sorta regulate the speed. Maybe the engine has a
speed
control, I dunno. Reverse would be a real problem. These look
heavy
but just cool as hell. I love simple stuff, great engineering.


http://tinyurl.com/create.php

Pep Boys Auto Parts had this 6KW diesel genset, electric start,
quiet cabinet, ISO900x certified, painted yellow but from this
Chinese company, for $1599 last fall. I'm running 2 diesel cars
and a V-8 diesel stepvan on used frying oil from Chinese
restaurants, so decided to buy one for the house in case of
hurricanes here in Charleston.

It's a great little genset, 120/240 60 Hz for the American
market. It turns 3600 RPM from its 1 cyl OHC 4-stroke diesel and
runs a LONG time on a single fueling. Its only headache is its
WEIGHT! The Chinese now seem to have VAST resources of HEAVY
STEEL and aren't afraid to USE IT in their products. It has
wheels for a reason. None is going to carry it off without a
fight...(c; The cylinder, for instance, isn't a cast iron sleeve
in an aluminum case...It's a CAST IRON CYLINDER, the old
fashioned way!

There's a compression release so you can hand crank it with the
included crank handle if the battery goes dead. Even comes with
a little AGM starting battery you can't pronounce.

I ran it on diesel for the first 20 hours to make sure it wasn't
going to be a return problem, but have migrated it, now, to my
cooking oil soup of 1 quart of mineral spirits mixed with 20
gallons of cooking oil and it cranks right up.

Whenever I crank it, my smartassed neighbor shows up with his
drop cord, the price I have to pay to run it 24/7 in
emergencies...(c;
I'll even have 220VAC hot water....

Larry
--
Merry Christmas!
http://youtube.com/watch?v=Qi_NhFS4xEE

On Tue, 11 Dec 2007 18:57:14 -0800 (PST),
wrote:

Somehow I found this site:

http://members.aol.com/westernstar66/indianlisters.html

that lists a 20 hp diesel for $3250, a real bargain for a new engine
compared to most diesels for boats. These are low rpm diesels that
can run on vegetable oil and are very efficient.

So, what would you do for a transmission? Maybe you could use a belt
with an idler pulley that was lever controlled. Tension on the idler
pulley would sorta regulate the speed. Maybe the engine has a speed
control, I dunno. Reverse would be a real problem. These look heavy
but just cool as hell. I love simple stuff, great engineering.

I have worked on the original Listers, that the Indians either
licensed or copied ,and they are pretty much a single speed engine, at
least the ones I worked on. As I remember there was a long screw that
tensioned a spring that the flyweights worked against to control the
rack. In addition they vibrate a lot. Bolted down to a 500 lb.
concrete pad they were pretty stable but I'd think you would need some
really heavy engine bearers if you were to install it in a boat.

Given that full throttle will probably be in the range of 1000 - 1500
RPM there is no need for a gear box (except to go backwards) so you
could direct couple it to the propeller shaft.

Bruce-in-Bangkok
(Note:remove underscores
from address for reply)