Rubber band powered race boat

thingiverse

This is a rubber band-powered boat I designed for the Maker Faire 2015 Moat Boat Paddle Battle Challenge. Check it out in action on a test run here: https://www.youtube.com/watch?v=8XWNFfDlJNM The propeller is a store-bought model boat propeller because consumer-grade 3D printers are not capable of producing high-strength, high-resolution models that propellers demand. A large-pitch propeller is ideal. I utilized a 2" T-pin as the propeller axle. I carved a slot in the tail of the propeller to secure it onto the T-pin's head. To estimate weight and volume, and calculate whether my model has sufficient buoyancy, I employ Autodesk Fusion 360. - Select the body to estimate in the browser - Right-click and choose "Properties," and a new dialogue box will display the volume, weight, etc. You might want to adjust the material for accurate estimates. - Measure volumes before and after hollowing out the hull with the Shelling command; this gives me the volume and estimated weight. - Calculate buoyancy: 1 liter can support 1 kilogram. I used an online calculator. - Make the boat's weight approximately half of its buoyancy. I then utilized Autodesk MeshMixer to check the center of gravity for my model. To fine-tune the boat's balance, I employed a small stack of rare-earth magnets. To hold the propellers in place after winding, I added a tiny hole to fit a drill bit. A small loop on the deck is used for dragging the boat back after it runs away. To reduce drag, I coated it with epoxy. Printing requires some support as shown in the after-print picture here. No issues occur if you print it lengthwise.