Electric Boat Design

[Stephen Ditmore]

By "Question 2" I assume you mean your 3:43 AM posting of 02-02-02. There are probably other people in a better position to check your formula and your logic than I am at the moment, but on quick inspection I don't disagree with anything you've said. Your Michlet result seems to show a very nice cancellation effect at your target speed, as you've indicated. Once you're confident of your weight estimate, your ability to generate an accurate resistance curve should enable you to optimise your propeller if you have a range to select from, but it's been a while since I've done propeller selection Is there someone else able to advise John on this?

[John Klimek]

I recently went to a seminar on stitch and glue construction. It was presented by Chesapeake Light Craft company in Annapolis MD. I was pretty surprised on the seeming easy way to construct a kayak with Okume plywood. What really interested me was I learned that they were willing to do custom jobs. They have a 4’ by 8’ CNC routing machine that they use to cut the plywood panels and sections from computer generated patterns. Annapolis is just 40 minutes from my home.

They use MAS epoxy. I was surprised to find out that there are no fumes from this stuff. It seems to be more encouraging for my basement construction prospects. I was also surprised that they do not use fiberglass over the whole craft. Just on the bottom of the hull for abrasion protection. There was no fiberglass applied to the inside of the hull, just the epoxy.

I would like to hear some responses from people who use stitch and glue construction. What are the pros and cons. My biggest concern with plywood is that you must have a developable hull; meaning that any piece of plywood used can only be bent in one axis.

Is there any software programs that you can input the hull offsets and find out if it can be made out of plywood? I have access to solid works 3D modeling software through my work. I have been trying to come up to speed on this software package. I see that it has a tool for sheet metal, I wonder if this can be used to determine whether plywood can be used. I believe it will take the surface and flatten it out so you can see the cut pattern for sheet material. I don’t know if it will indicate how many bend axes must be made to get the desired shape. Any help here would be much appreciated.

[John Klimek]

As I posted ealier, I have been playing with Solid Works. I mange to loft the under water surface of the hulls as shown below. I need to come up with the above waterline surface for the two amas and the main center hull. The center hull will be extended up to the underside of the deck surface. With the two amas I am not sure on how to go about designing them. The craft is not going to be under sail and it will be used in protected waters. What are some good design guidelines should follow? How high up off the water should the deck be?

[John Klimek]

I see another post in the software section of this design forum has the same question I asked about developable surfaces...

http://boatdesign.net/forums/showth...s=&threadid=266

I read Plate Development and Expansion by Stephen M. Hollister of New Wave Systems, Inc....

I think I might have to stick with the Cedar strip technique. The hull shapes produced by Michlet programs are continuously changing in x,y,and z directions.

Please comment on using MAS epoxy inside your house in the basement.

I have not heard any responses to the question about estimating required horsepower (02-01-2002).

[Stephen Ditmore]

One thing I've wondered is whether you could use a tortured plywood method similar to that used at
http://www.by-the-sea.com/stillwaterboats/
to build multihulls. I see it being analogous to sailmaking; you could use a sailmaking program to shape each piece of plywood like a sailmaker shapes panels of sailcloth, giving each edge some curvature before scarfing them together.

For info on how to do it using foam & fiberglass, see
http://www.dcss.org/ayrs/newsltrs/july97/ and, on the left, click on "Quick Hull-Building."

You might also check:
http://www.kelsall.com/
http://www.index.co.za/collins/collins_p13.html

[Stephen Ditmore]

As for software, check out Touch 3D at
http://www.algonet.se/~ludesign/
(I haven't used it - someone asked about it in these forums, and having looked at the web site I'm very curious. Lack of a Windows version is a handicap, though.) Note also - any lines fairing program with Gaussian Curvature analysis will give you an idea where the problem spots will be.

[Nomad]

John Klimek nice choice of software (solidworks) it is my favorite.

p.s. how long have you been using it?

[John Klimek]

Wow, it’s been almost 10 years since I began the electric boat design thread. The boat has still not yet been built but... I am still planning on doing it. I have had things (like family and life in general) which always seem to place a higher priority on all those other “things” which prevented me from diving in to boat building. I am however beginning to see the opportunity coming back around as the kids get married and get through college.

I have decided that I will not build the boat in my basement but will rent/find a suitable place to build it. Basic build parameters are very similar to the original but now I wish to take advantage of new technology:

1) Electric power - current motor identified is now a Torqeedo CRUISE 2.0 R / 4.0 R (was Ray Electric Outboard, system 300)
a. 2 to 4 Power 26-104 lithium batteries (was eight 6 volt E-145 batteries in series, 48 VDC)
b. 125 lbs (2 batteries and motor); 213 lbs (4 batteries and motor) ; was 679 lbs motor and battery weight with lead acid batteries
2) Primary purpose – fishing with four people, must be very stable, used on protected water, reservoirs
3) Sustain 6 MPH for eight hours , 48 miles per charge
4) Length overall – 12 ft minimum, 18 ft maximum.
5) Desire to have trailer width equal to or less than 6 ft wide

To be continued…

[Leo Lazauskas]

Originally Posted by John Klimek

Wow, it’s been almost 10 years since I began the electric boat design thread.

The Boston Red Sox won the World Series in 2004.
HTH.
(Time travellers need that sort of information to avoid attracting suspicion.)

[John Klimek]

Leo, I am glad to hear from you as it is your work with GODZILLA which had originally hooked me into designing an efficient electric powered multi-hull. I spent part of the morning looking up how I did the original hull designs using michlet 6.06. It will take some looking into some of my old runs to resurrect my knowledge on how to use it again. I am looking forward to it.

A side note: looking at boat designs I came across the Planet Solar Turanor (http://fundudes.blogspot.com/2010/04...d-largest.html) which looks pretty impressive. If you can image scaling this yacht down to 18 feet long and the top solar panel area as a fishing deck, this is what I am aiming for.

Amazing how time flies…
Cheers

[Leo Lazauskas]

Originally Posted by John Klimek

If you can image scaling this yacht down to 18 feet long and the top solar panel area as a fishing deck, this is what I am aiming for.

Scaling down should make for a fun hobby project.
Of course, scaling up to cargo-ship size is the real challenge!

All the best,
Leo.

[Chase_B]

I had to reply because I have a gas/electric pontoon boat,..with a built in trailer ,..it can haul 4 adults,..if I go on water that is regulated for no gas engines ,..I take the outboard off the back,..I have a 50 lb thrust trolling motor,.. foot controled mounted on the nose/bow,.. I used just the trolling motor for the first 2 months with this boat ,.on the Piney River ,..which flows avrerage at 3 mph ,..but has places that flow up to 10 mph ,..the trolling motor beat the current but at a slow pace in the 10 mph current,..I have 2 deep cycle batteries that run the retractable trailer wheels ,..the trolling motor and the NAV lights ,..I could get a full 4 days use before I had to charge them,..the boat is fully self contained,..back her down to the water and flip the switch to retract the wheels ,..unhook the hitch and slide it back under the deck,..there are photo's in the "boat building" section under "River Pirate"

[Chase_B]

PS ,..the above posted boat weighs 300 lbs +/- with all the gear on it ,..trailer wheels ,..hitch,..batteries,,boat motors,..seats,. I didnt use any programs to build it,.. I knew what I wanted,..I built it