I made one of those a few years ago... about 1/5 of the scale as the one on the image. With a trough of about 2 meters, a beam of 3-4 meters and about 30-40 bricks as a counter weight. It could throw 5 kilo boulders or snowballs with a diameter of .5 meters about 45-50 meters away. Modanung 00:28, 18 December 2007 (CET)