Earlier this week I made a lighter arm for my much-rebuilt 4-foot-high trebuchet frame, which has been around in various incarnations since about 2006. So I got out the Flip camera and shot a little footage, or whatever the digital equivalent is called. I stuck a title in front and let Movie Maker paste the clips together, no attempt at editing.
In case anyone's interested, the arm is made from salvaged 1X4 boards fastened together with Gorilla Glue. The long side is 48", and the short side is 13, similar the the pumpkin-throwing arm but half the weight. As it's set up now it's using 2 10-pound weight plates to throw tennis balls. Sling is my unisling design, and trigger is a double trapdoor arrangement adapted from Ron Toms's original floating axle treb. Steep cocking angle gives a longer arm rotation and more counterweight drop for more energy.
Performance is guesstimated, as the balls go over the house, being recovered on the lawn across the street. On the far side of a mini van parked over there. One bounce, I imagine.
Plans are to change CW to 2 25-pounders to throw baseballs or softballs (in the park, too dangerous for at home). I expect around 250 feet.
http://www.youtube.com/watch?v=6C5gK1br0nMAnd for Curious Aardvark's edification there are trigger details.
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Another treb video (Read 4325 times)
