This is an instructable for making a small rubber band powered paddle boat. I sketched it on Autodesk Inventor and used a 60 watt Epilog laser cutter to make the parts. Quite a bit of experimentation was required to get this to kind of work.
I sketched it on Autodesk inventor. This is a really simple, 2 extruded solids part. I designed it to be built from 3/16" plywood that I was using for another project. This came about as an idea to use up extra space on the pieces of wood I was using for cutting. Only half of the paddle is drawn because it's 2 interlocking identical pieces. The slots are drawn 3/16" wide and half the width of the paddle.
I have included all the CAD files and a .pdf that it setup for a 6"x6" sheet of wood. It requires 4 pieces to be cut. 2 layers of hull and 2 paddle pieces.