Science Buddies: "Ask an Expert"

I want to know what length I should make the throwing arm of my trebuchet, if the base length is 56 inches. I've read a few places that say 1.5 times the length of the base is good, but I want to be sure.
Also, how does one change the pin angle (release angle), if it has to be a nail hammered into the throwing arm?
An answer soon would be helpful. Thanks

Hi simsim21,

I think that the trebuchet “arm length” depends on several factors like the projectile weight and desired trajectory, and dimensions of other parts of the trebuchet.

A lot of information about trebuchet design is available online. A pretty good summary of the trebuchet dimensions that affect projectile flight is at this link:

https://www.sciencebuddies.org/science- ... ml#summary

And the following link has a simulator that lets you see the effects of changing trebuchet dimensions with different projectiles.

http://www.virtualtrebuchet.com

I hope this helps. Please post again if you have more questions.

A. Norman