Trebuchet

This trebuchet was designed and built as a school project. All structural parts are 3D printable and the design is easy to assemble with a few simple hardware components. It is intended for launching lightweight projectiles and is a fun demonstration of medieval siege engineering and basic physics.

Specifications

• Counterweight: 500 g

• Projectile weight: 10 g

• Sling length: 18 cm

These values were used during testing and provide good launching performance.

Assembly Instructions

• Drill all printed holes to the correct diameter so the axle can rotate freely.

• Insert the metal axle through the frame and throwing arm.

• At the tip of the throwing arm, install a small nail or metal pin. The sling loop hooks onto this pin and automatically releases during the throw.

• Place the 500 g counterweight into the counterweight holder and secure it if necessary.

• Attach an 18 cm sling and use a 10 g projectile for the best results.

• I got optimal distance with this setup up to 7 m

Printing Notes

• Print all structural parts with enough infill (around 30% is recommended).

• PLA works well, but PETG is also a good choice if you want better impact resistance.

• The base should be printed in TPU (or have TPU feet attached) to prevent the trebuchet from sliding during launch. A non-slip base greatly improves consistency and launching distance.

Hardware Required:

• Metal axle 12mm

• Small nail or metal pin for the release hook

• 500 g counterweight

• String for the sling (18 cm)

Feel free to remix if you need.

If you need any questions let me see in the comment.