Help with my traction trebuchet?

A friend and I built this traction trebuchet, the Flying Lemon, out of PVC plumbing pipes. In this short video it hurls a kiwi about 70 meters.

Can anyone lend some insight as to how to get more range?

The throwing arm is 2m total, and the long end is 1.6m. The sling is about 7/8 the length of the long end. The kiwi weighed about 120g. I'm considering making it a proper trebuchet by adding a counterweight. I also think either adding wheels or anchoring it more firmly to the ground could have positive results.

Any help would be welcome!

Category:

Science & Technology

Tags:

• trebuchet
• traction
• catapult
• pvc
• pipes
• plumbing
• siege
• kiwi

[akitist]

There's not a lot of info about traction trebs out there. 70 meters is pretty good, actually. You'd probably lose performance converting to a counterweight design. You could try different sling lengths to change the trajectory is you want to.

[RSammy]

You think I'd lose distance by adding a counterweight? Interesting. Can you explain why? The physics behind these things is pretty fascinating.

[jjbad12]

Late, but hopefully useful: Try anchoring the base to the ground. Also add wheels to the axles to act as "cams", lace them with rope. Use two people to pull the ropes to launch. Basically you're doubling the power (2 people pulling vs 1 pushing), creating a larger fulcrum with the wheels, and wasting less energy by keeping the frame locked down.

[angagaur]

Consider going halfway.

add some weights to offset the payload's mass, but no so much that it will put the loaded arm through a fireing motion.

[akitist]

Well, with a traction treb the shooter is the counterweight. Do you think you could load your frame up with the equivalent of your body weight as CW? Also, your machine is interactive; you can apply the force more efficiently than simple gravitational pull on a CW.