3

Pulling the string releases the swing arm and launches whatever is in the pouch.

Straighten out a coat hanger and cut a length about 15 inches (38 cm) long. Make a small loop on one end of the wire and attach some string to the loop. Bring the swing arm of the trebuchet down so that the counterweight is in the air. Feed the straight end of the hanger through the first hook on the base, then through the front hook on the swing arm, then through the second hook on the base.