So, I've designed a hull in....

the free Carlson Hull design program. It looks good and seems to meet all of my requirements. However, I do not now how to turn the lines on my computer screen into plans I can follow. I have a fair amount of woodworking experience and am confident in my ablities -- if I had good plans.

All I really want is the measurements from my bulkheads, including lengths of each line, angles, and placement along the length of the boat.

Is there an easy way to get this information?

 

you can save your templates as a DXF files and open this ones in almost any cad software, there is many of this ones for free and they will allow you to make dimensions of your bulkheads and frames, besides this, if you don't want to use a cad program for support you can print the offsets of your frames. there is a file called "handplot" and it has all the offsets of the frames.

 

Here's a thread on free CAD-software:

http://www.boatdesign.net/forums/showthread.php?t=4871

 

BTW, can we see the result?

 

I'd love to show you and get your advice on it. I've done the best within my ability, but I am still not confident on the deadrise and shape of the bow.

Can I post the Carlson Hull Designer file somehow, or should I first transfer it to CAD?

Dan


P.S. '“The opinion of the majority is not necessarily correct” – Yi Qing Cui' -- You might enjoy reading John Stuart Mill's "On Liberty" where he discusses the tyranny of the majority.

 

Wouldn't want some running away with your design! Why don't you do a "print screen" and post the jpg-file?
Otherwise post a dxf-file, disadvantage is that everyone with a CAD program can download it, but if you don't care, that's the easiest way.

 

I downloaded a trial version of Rhino and opened my file in it. The problem is that it will only my boat in 2D. Am I doing something wrong?

 

Did you export it as being a 3-d dxf ?

 

In the hull program go to "File" on the top menu bar and then select save and create. Then save it, now you have the opportunity to then go to "Patterns" on the menu bar. It will let you lay out all the pieces and print a scale layout of plywood sheets with the shapes on it. It also will print out a table you can use to draw the shapes on plywood.

 

Okay, I attached the .dxf file. The only problem is that it is still in 2d -- not sure if that can be avoided.

Let me explain the boat before you look at the file.

I am building a pontoon/catamaran that I will use for extended boat camping trips (5-10 days). I chose the catamaran platform because I figured it would give me the initial stability I need and the largest flat surface for setting up my tent with the least amount of beam. The file shows one pontoon.

It is a v-bottom with constant deadrise. The "v" is rather deep and I thought this would give me a smoother ride in waves. I also hope to be able to raise the boat up on a plane when I can afford a large enough motor. Though, a smooth ride is by far my priority.

The bow might be a bit unusual. The profile of the boat is a perfect rectangle. I created what I thought would a be knife slicing through the waves. I want pounding to be as slight as possible. I expect this "knife" will not cause problems at displacement speeds, but I wonder if it will prevent me from getting the boat up on a plane. In 3D it reminds of an old transatlantic ship.

I still need to design the deck and perhaps a small cabin (in lieu of a tent) if extra displacement is available. So, I may need to change some dimensions if my estimate of total displacement was off (I'm still looking for my little book that has the weight of most construction materials).

So, I have the following questions:

1. Is my deadrise too steep?
2. Will my "transatlantic bow" prevent the boat from ever planning?

Thanks for any comments.

Dan

Note: In case the file doesn't show it: waterline length is 192 inches, max beam is 25 inches, max height 25 inches


This Carlson program will create a WRL file, but I tried to view it in a trial version of Rhino. Nothing comes up on the screen.

 

Dan,

I missed that last time! I'll see if I can find it!

Regards,



Peter

 

You need the cortona viewer to see your WRL, rhino do not open WRL files at least not in V2.

here is your boat in 3d, i think that maybe the pontoon has to be more narrow

i hope the file helps

 

Dan,

Looked at the file.
To be short: No, don't think deadrise is to steep.
No, don't think bow shape will prevent boat from planing.
But, I think you have to flatten the aft part if you want planing to be possible.
What area are you going to camp? Are waves so high you need to be afraid of pounding? If this is the case you have to check the hight of the platform above the water!
There is a thread with a spreadsheet on how to calculate planing boats, atleast the power you need, it must be possible to make some calculations for your cat with that!
Here is the link:

http://www.boatdesign.net/forums/showthread.php?t=2187&page=3&pp=15&highlight=planing

I hope I was of some help!

 

I made some adjustments on the shape of the hull. It still begins steep but then gradually flattens moving aft.

I have considered the wave height problem. Once I design the deck I will see how high it is and if necessary can increase the height of the pontoon without changing any other dimensions.

I want a smooth ride so that daily activities will not be interrupted while traveling. Perhaps I am too ambitious, but I plan to take a long cruise down the west side of the Outer Banks in North Carolina. I need to be able to cook and generally go about life while moving at displacement speeds.

Your advice has been valuable. Please critique away! Only a fool would turn down free help from the pros.

Dan

 

I've realised that I made a big mistake. In the "calculations" menu I set the maximum beam to be 25 inches. I thought that was the full beam -- apparently that calculation refers only to half of the beam. So, my pontoon is 50 inches wide!! I wanted the entire boat to be not much over 96 inches wide, so obviously these pontoons won't work.

I'm going to have to make them narrower.