The TK3 Trebuchet Model Kit is an ideal science project machine! Use the hanging counterweight bucket for variable weights, or convert it to a fixed counterweight machine, wheels, or no wheels. The choice is yours!
$79.00 more info
A fascinating machine that converts potential energy into kinetic and uses it to throw a ball, this machine is only 34 inches tall, 18 inches long and 12 inches wide (including the steel counterweight boxes) but it hurls a golf ball over 200 feet.
$195.00 more info