# how to calculate weight of pilot for scale model kayak?

• posted

I am making a 1'=1"model of a kayak to get a rough idea how the full size boat will behave with a 200lb pilot in it. I am not sure how to go about calculating the proper weight for the scale model pilot. I know it is not 1/12 of 200lbs or even 1/144 of 200 lbs since those weights are way to much. Anyone have some clues for me? Thanks.

• posted

How about 1/1728th, the cube root of 200lbs?

(kim)

• posted

• posted

I second that.

Weight is proportional to volume and the scale volume is 1/(12 x 12 x 12) =

1/1728

So scale weight is about 1.85 oz.

Cheers,

Nigel

• posted

I would agree, except depending on how far you want the modeling to go, the weight of the kayak and the pilot is proportional to water displaced by the floating combination. So, you need to consider the weight of the kayak divided by 1728 as well.

T2

"Nigel Heather the-heathers.co.uk>" I second that.

• posted

While, as others have said, using the cube root will get you the answer as far as displacement, waterline, and static behavior, the dynamic responses do not always scale by the same ratio as static responses. Things like moment of inertia and stuff will take more complicated scaling.

• posted

Thanks everyone for the great and prompt help!

Michael

• posted

I use sharmon's double ply toilet paper in my bathroom.

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