Filament Derby

thingiverse

CDs and pencils appear to be the perfect tire-and-axle combination for a low-budget vehicle challenge, but combining them is a real headache...unless you print out the rims. I started by attempting to build up from a circle - unfortunately, FreeCAD didn't take kindly to that idea. I tried sketching a cross-section and rotating it - this worked great for two wedges, but it refused to paste or map onto the raw edges without arbitrarily mirroring, and there's no option to flip it back. I also attempted to sketch out the cross-section 12 times, but that resulted in a crash. So here's the two wedges copied and pieced together. I'm eagerly awaiting FreeCAD's working Assembly workbench... There are a few issues with the design, but you get the idea. The fun part is making your own! Project: Filament Derby Objectives Students will gain a solid understanding of basic physics laws - drag, thrust, wind resistance, and more - in addition to learning 3D modeling. Audiences High school or junior high school students would be perfect for this challenge - customized circular models are crucial to success. Preparation Students should already know the basics of designing and printing simple 3D models; teachers should have established limitations beforehand (can they 3D print the entire car? Are they allowed to download designs from the Thingiverse? How long do they have? Can they work at home? Can their parents help?). Steps! Students should form groups. Students design their vehicles - frame, wheels, and motor. Using rubber band power or different power sources can be a good idea. Students model and print the missing components - drinking straw connectors, pencil hubs, clothespin axles, etc. The groups then compete in a large indoor space (the gym? Cafeteria? A hall?) - prizes are awarded for the car that achieves the best time and the car that goes the furthest on onboard power. Results Each group will have created a vehicle; grades can be based either on the performance of their vehicle or on the effort they put into construction.