Paddle Wheel Design
The paddle wheels, like the hull, were designed and optimized for weight, speed, and robustness. Thin aluminum sheet was used (thinner than 1/32") to meet this design criteria. The key to paddle wheel design is that the paddles should be pushing water back, and not scooping it up. Because of this we went with straight blades on the paddles that contacted the water about 1/2". Below we document the design and fabrication of the paddle wheels.
Fabrication
To fabricate the paddle wheel we start with a template that was designed in Sketchup. The template includes lines to indicate where we want to cut and bend/fold (sort of like origami, sans the cutting). When finished cutting and bending one sheet, we put two of them together using our trusty waterproof tape to make the paddle wheel rigid. Below are several pictures of the fabrication process:
