Rubber Band Catapult

thingiverse

This is a catapult that I designed using Fusion 360. It's one of my first projects using this CAD software, so please let me know if you notice anything that needs to be added or improved. This design is the result of about five different versions that I printed. I tweaked details in between versions to make it stronger, more efficient, etc. I finally thought it was worthy enough for Thingiverse, so here it is. The filament I used to design this catapult is significant because as a broke college student, I had to sacrifice some of my limited resources. If you're willing to help out with tips or donations, I'd use the money to buy more filament and continue designing cool stuff. Parts Needed for Assembly: 1x Bottom Frame 2x Upright 2x Stop bar half 2x Bottom bar half 1x Throw bar 1x Cradle of your choice All you need is some superglue, various sizes of rubber bands, and a bit of patience. You can assemble the catapult easily with just these tools and the pictures provided. If you're unsure about anything, don't be afraid to ask for help. In the future, I'll try to add more specialized cradles to this design. However, if you decide to print another cradle after assembling the parts, you'll need to print a new throw bar as well, assuming one is already glued to an existing cradle. These parts print well on my Maker Select V2.1 and require no sanding. Depending on your printer's accuracy, you might need to sand a part or two. Tips on Printer Settings: 100 percent infill would result in the strongest catapult, but I recommend using 40 to 50 percent infill for most of the parts. Three or more perimeter walls will also help strengthen the design. If you have a .4mm nozzle, try using a .2 or .25mm layer height, as it's the strongest layer height for that size nozzle. Be cautious when scaling up or down because it affects the tolerances between the parts and may cause them to be too loose or too tight. I haven't tried scaling yet, but if you do, please report your findings. Use supports for the uprights and cradles to support the insertable tabs. Feel free to give me suggestions or create a remix of this design. I'm sure there are still flaws in it that can be improved. I'm thinking of different cradle designs, such as one that launches dog treats or another that launches an arrow. If you make a cradle, please let me know so I can link it here. The tab at the bottom of the cradle is 13mm by 2mm by 4mm deep, and the insert in the throw bar has a .3mm offset around it. If you print my design, take a picture and share it with me. I'd love to see how it turns out. Cradles: Double Quarter- Launches two quarters! Basic Rectangle- Could hold various things, 27.5mm by 22.5mm capacity 10mm Marble- Holds a 10mm (1/2 inch) marble