Scale Models

[welshkc]

I would like to build a scale model catamaran. This requires some limited plans for the exterior dimensions and I can't find them anywhere. For sale or otherwise. Full plans from a designer are way overkill and too expensive.

Has anyone on here seen something like this or built a scale model who could give pointers?

First choice are the Leopards from Robertson and Caine then Lagoons.

Ed

[David M]

I once had to order a set of plans from Sparkman & Stephens for getting a boat USCG certified to carry passengers. They were understandably very guarded with their plans because they do not want someone building a boat using their design without their authorization. In the end they did send me the plans for a little more than the cost of printing and shipping with the understanding that I was not planning on having another boat built.

The best thing may be to take profile photos of the hull from the exact X, Y and Z planes of the hull and then superimpose a grid over the photos so you can better quantify the dimensions. Put something in the photo that is a known width and height. Of course get back far enough from the hull so that the stretch effect of being in close does not throw off the ratio of the true dimensions. To detect this, put something of the same dimensions on the hull at the edge of the frame and the center of the frame and then see if they end up the same size in the photo. Of course you will also want to send plenty of time with a tape measure confirming different dimensions.

Hopefully this can get you close enough to do a scale model.

[Roy M]

I took my lines drawings, a scaling ruler, and my Excel spreadsheet program, and made a table of offsets. Then I transferred the x-y coordinates to a CAD program and made some layered drawings of the boat in three dimensions. My plan was to someday build a scale, radio control model, but I haven't gotten to that level of inactivity, yet. The real reason was to document the electrical, plumbing and other systems, and to create a storage space document for cruising. It doesn't have to be perfectly accurate since you will probably have to "fair" your lines anyway, just like when you build any boat to offsets that don't exactly fit the real world.

[Dave]

I've thought about it also. The Leopard manuals have some line drawings that certainly appear to be in scale. Side, front and partial rear views. Not plans by any strect..but a pretty good start. I have had good luck importing them into a 2D cad program and designing mounts to scale for solar and wind turbine mounts. I have the Leopards 38 manual in .pdf PM me if you want to take a look at it. It's about 6.5 meg. albertaw at telus dot net

Dave

[welshkc]

The guys at leopardcatamarans.com were kind enough to send me some line drawings of the new 38. They only show the boat from a top view. Now I need to get a profile and bottom drawings with some measurements.

I've decided to use floral foam to carve out a plug for fiberglass molding. It will be challenging since I haven't ever done anything like this before. Sculpting from the bottom up for the hulls half and then from the top down for the deck half with flanging for mating them.

That's the plan. Still looking for drawings to fill in the gaps.

[Aussiesuede]

Originally Posted by welshkc

The guys at leopardcatamarans.com were kind enough to send me some line drawings of the new 38. They only show the boat from a top view. Now I need to get a profile and bottom drawings with some measurements.

I've decided to use floral foam to carve out a plug for fiberglass molding. It will be challenging since I haven't ever done anything like this before. Sculpting from the bottom up for the hulls half and then from the top down for the deck half with flanging for mating them.

That's the plan. Still looking for drawings to fill in the gaps.

Construction foam boards are infinitely easier to work with and respond much better to sanding. Here is a writeup from an RC Group forum describing the "Lost Foam" method. I built my RC submarine(s) using this method and was very satisfied with the results.

The Lost Foam Technique for Making Fiberglass Parts - RC Groups

[clausont]

We used the line drawings for our Ingrid 38 and scaled them to build a semi scale model for the kids to play with in our pond. It worked out well for something that we just put together pretty quickly.