electricboats@yahoogroups.com
Hi, Jim,
Just a thought, now bear in mind I have never yet sailed, nor do I yet
have an electric drive, just a 26 footer and an A4 like you!
I don't think that you ought to worry about regen.
My thinking is that if the sails propel the boat at an average of, say,
4 knots, then to regen to the same power level that the sails supply
would stop the boat dead. Maybe this simplistic thinking is incorrect?
There are options to have a regen system that can be taken out of the
water, and rigged for wind as well, I think it is aqua something.
Probably expensive. Other members will know what it is called.
As I am planning a 'lightweight' (as far as power goes) system, we seem
to be in the same BOAT (good one!).
My latest thinking is to go with solar, even though I have little room,
and hate the look of them. At the same time, one thing allows another,
and by having a small battery bank, like one or 2 batteries, solar
becomes viable, I think, even up here in Canada.
Being cheap, I am holding off buying my number one motor choice, which
is a 500 watt 24 volt Chinese scooter unit. The cost is $89, the
shipping (for where I am) approaching $60! Then I might get nailed for
import duty on top of that, who knows. So, I am seeing if I can get
something locally, but so far, all the designs are wheel hub motors. My
next searching will be via hospitals, to source out mobility scooter
repair shops. Golf cart motors re not an option for me here in Nova
Scotia. Fork lift motors are snapped up by EV people.
I might even go back to a previous idea, and try using a DC generator of
the A4 as a motor, I ran it no-load, but there seemed to be no useful
torque.
My suspicion is that using a direct drive, with minimal power, then prop
choice will critically control the RPM.
My way around this is that I am building a stand-alone practice unit
that I can test using my 15 foot dinghy. It is basically a 6 foot piece
of black ABS sink drain pipe, with a 3" (pipe size) toilet outlet flange
adapted onto one end, to give a place for mounting the motor, (and a
plate for lightweight toothed belt drive if I am forced to).
A 3/4" stainless shaft, and the rest, I still have to figure out. Like a
long outboard, but with no right angle in it.
My goal for my 26 footer 6000 pounder is to have about 4 knots as a max
speed.
Eric did some tests on amp draw at various speeds, and 500 watts seems
doable, provided the goal of hull speed (6 knots maybe?) is
rethought/ignored.
I am beginning to see why commercially available setups are what they
are - if I had a few more bucks, I would get a 'proper' unit, maybe 3 or
4 kw, and cut costs by having smaller batteries. Like you, my expected
usage is maybe a few minutes each outing.
But, as I say, I think that you are trying to do too much at once by
considering regen right now - maybe get the power part running first.
Then find out the actual wattage used per week, and look at charging
options closer once you have the figures.
My solar panel plans are one directly in front of the sliding hatch
cover, so it will be covered when the hatch is open, and hidden from the
sides by the sliding rails, and if that isn't enough, a couple more that
can be folded out somehow onto the cockpit seats when the boat is
unattended. I am currently putting wind power on the backburner due to
unattended safety issues, and noise.
Bill Gates ignored me, too, and started giving his money to other
charities.
John
3a. Re: Incremental Options
Posted by: "jim_ranger_26" no_reply@yahoogroups.com jim_ranger_26
Date: Wed Jun 15, 2011 10:10 pm ((PDT))
Just Li'l Ol' Me again,
I forgot to include that another incremental option will be upgrading
the prop from the existing two-bladed, shallower-pitch standard model on
the Ranger 29 used with the Atomic 4 ICE, to at least a three-bladed,
larger-diameter, deeper-pitch prop that has forward and aft faces
optimized/traded-off as much as is possible for both propulsion (pushing
the boat) and regeneration (the prop being pulled through the water
under sail power). An underway-adjustable-pitch prop might be even
better for achieving the differing propulsion/regeneration
characteristics, but, that would definitely be an even further
incremental option that could only be explored after the upgrade to the
larger, increased-blade-number, deeper-pitch prop, unless an unknown
relative leaves me a treasure chest in their will (I've been working on
getting Warren Buffett to adopt me, but, so far, I haven't seen the
paperwork come through :)
All the Best,
Jim
--
http://www.fastmail.fm - Or how I learned to stop worrying and
love email again
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