Toypedo

thingiverse

Uploaded a smaller 3-blade propeller model seen in the video update on August 2nd. Tweaked coinweight models to prevent splitting when inserting the coinweight_clamshell part. Added more room for clamshell insertion and strengthened the breaking part. This toy is an underwater torpedo powered by a rubber band, driven by a propeller. Assemble components, wind up the propeller, and see how far it goes underwater. The Toypedo is designed in rearrangeable sections that change its dynamics, making it suitable for thought-provoking pool-time fun for kids. Things kids can learn: • Moving weight and buoyancy affect the travel arc. More buoyancy in front makes it curve upward, while more weight in back does the same. • Newton's third law: When the rubber band twists one end of the propeller, it also twists the other end the opposite direction. Remove fins to illustrate this easily; the back section spins faster. • Inertia: Add coin-weight sections and see how it affects acceleration. Reconfiguring ideas: • Swap fins for another backward propeller (using double-male connections) • Get a longer or shorter rubber band, add or remove hollow shaft sections as needed • Minimize weight, maximize buoyancy, and aim the Toypedo upwards. Will it come out of the water like a killer whale? • Aiming upwards, see how much weight keeps it from moving when spinning Redesign ideas: • Design an optimized propeller • Redesign Body assembly to reduce drag • Design a shaft section with a big flat disk to demonstrate drag • Design a spring-driven system and get rid of the rubber band Small propeller test: https://www.youtube.com/watch?v=FBwe6xVVXEU Large propeller test: https://www.youtube.com/watch?v=ITS9-C_qkNI Other Thoughts: • My favorite thing about this toy is its modularity. Community members can improve the design, and because it's designed in sections, they can print and test ideas without reprinting or redesigning. Note that there's a .zip file labeled "Gearassm" containing parts for a coil-spring powered version using bevel gears to reduce gearing. Even with current gearing, springs still act too fast; the propeller goes "Blrrrrp" briefly before finishing action. I believe this idea can work with more gear reduction, but time constraints focused efforts on the rubber band powered version.