How big must a model be to be useful assessing a multi-hull design?

To Peter,

Thanks Peter. Keeping expectations reasonable is a theme here. As a kid I would whittle outrigger sailing canoes that would zip across the lagoon carrying hapless hermit crab sailors. It only took a few hours and I learned a few things, a curved aka was much better than straight for example. These days with a 3d printer and a hot wire cutter I'm hoping in a couple days I can whip up models that might be ugly but are sufficient to test ideas. But yes, for sure I'll take all results with a grain of salt!

 

That is a interesting and useful link. Thanks! As an ex-electronic design engineer I relied heavily on spice, verilog etc. to design and simulate before actually making things so I value simulation and design methodology. I'm using Freecad and openscad for my design work and I've considered ramping up on finite element and fluid simulation but the time investment is huge and I think for a design like this they are way overkill. For now I want to understand some first order considerations such as the weight in the vaka vs. the ama question. Once I've wrapped my head around these questions I think I would go with the folks arguing to just build the dang thing. If the ama starts to oscillate in a scary way, slow down, turn around and head home for a redesign!

 

You have also these ones, proposed by Metz boats :
Trika 540 : http://www.metzboats.de/pdf/trika540_eng.pdf
TriRAID 560 : http://www.metzboats.de/pdf/triraid560_specs.pdf

 

"seems to be" versus proven performance from numerous Strikes built.
Entire forum threads dedicated to Strike builds and their performance characteristics.

For performance make your ama's skinny and light.
How are you going to attach them to the vaka?

Why the sudden addition of 3' ?
16' wasn't long enough?

 

I haven't committed to a specific length, 16' seems pretty reasonable but 19' seems nicer. I had an Oday 192 and looking back it felt too small but it was a lot of work to get that thing in the water.

I didn't mean to slight the Strike, boats are funny things and sometimes even when they check all the boxes they still don't sit right and that is the Strike for me. I'll build some models and test some ideas and then as I quipped in a previous post likely go buy some old easy to register monohull and just go sailing. I just have to get some likely bad ideas out of my system first.

 

With a hot wire cutter and some recycled polystyrene you can quickly test having weighted amas vs weighted hull, or a possible useful balance, regardless of the model's accuracy to your intended plans, without using R/C, or sensors, just messing about like a kid again. I'm sure it's all been done before, and someone has written it up somewhere; you just need the right search terms.
There is a ratio statement that goes something like: the amount of fun to be had is inversely proportional to the size of the boat.
Eg. I sail my 10 footer more often than my bigger boat, simply because it's easier launched, and up and running much quicker, and also less stress in difficult situations. Tradeoff is less room for joy riders/crew.