Single Piece Desktop Catapult

thingiverse

Somebody I worked with picked up a plastic catapult made by Stratasys out of Ultem while at a conference, and it was built as a single piece using torsional windup of the throwing arm axle as a spring. This catapult works on the same principles and uses two arms to launch a small ball of paper a significant distance. The first arm holds the second arm in place, acting as a trigger when released. Intended for printing with PETG or other stiff yet elastic materials that aren't brittle. This design is still a work in progress as I refine cross sections and tweak settings. Print Settings: Printer: SeeMeCNC Rostock MAX Rafts: Doesn't Matter Supports: Doesn't Matter Resolution: 0.25mm Infill: 25% Notes: PLA and ABS may only last for a few uses before breaking with this design, but PETG has worked well, lasting over 100 uses without damage, except for minor permanent set in the arm's resting position. There are two ways to print this catapult. The first method involves using removable supports for both arms, although I haven't tried it myself. Alternatively, you can cut off the first 1mm or so of the model using a z offset option in Simplify3D, ensuring all pieces touch the build platform.