The 3DOF Trebuchet

A full 3DOF trebuchet is shown in the figure above. This is the traditional trebuchet - the favorite of students of Physics and Mechanical Engineering everywhere. The main difference between this and the 2DOF trebuchet is the ability of the counterweight holder to swing back and forth. This permits the counterweight to fall in a more nearly vertical trajectory, which increases the efficiency of the trebuchet.

The required dimensions are the same as for the 2DOF trebuchet, with the addition of the counterweight length. The height of the pivot (h0) must be less than the arm length L2 plus the sling length L3 or the trebuchet won't have a valid starting angle.



Lengths (in meters)

Lengths (in meters)

Launch hook angle

Masses

Density