The Trebuchet is a medieval siege weapon that uses a counterweight to hurl a projectile. Trebuchets date back to the 4th century BC in China, and were used throughout medieval Europe as siege weapons used to attack large fortresses such as castles. The trebuchet is an impressive piece of engineering and a great display of physics, which can be easily replicated and built on a smaller scale today. I mainly used this post from comsol.com written by Mats Danielsson which contains great information on the physics behind an ideal trebuchet, such as the proper ratios of counterweight mass and arm length.

Building this small model of a trebuchet is a basic, fun, and engaging way to see how physics works. This model stands at 8 inches tall and is made to work, but I left room for tinkering and improvement. It launches small projectiles such as M3 nuts tied to a string. The trebuchet can throw 5-grain projectiles about 5 feet. The model was made in Onshape and uses metric millimeters. All of the 3D models are available down below and were printed in about 3 hours collectively.

Along with a 3D printer, you'll need

• (1x) M3x30mm hex socket head cap screw
• (1x) M3x16mm hex socket head cap screw
• (5x) M3 nuts
• (1x) 5mm x 13mm x 4mm ball bearing
• Super Glue
• Small and heavy objects to be used as a counterweight.
• String
• Tape

[Model was originally posted on Instructables by myself, however, I am reuploading it to Printables to share it with more people. You can also find assembly instructions here]