Sunday, August 26, 2007

Trebuchet Part III: Saturday in the Park

On Saturday some friends and I went to the park for the first full day of trebuchet baseball flinging. For most of the morning it was Brain, Jackie, Jackie's dog, and I working out the kinks. Trevor, Sarah, Colin, Adriana, Lisa, and Brett all showed up at some point during the day too.

A good deal of the morning was spent taking video of the trebuchet from the side as it was firing and playing it back in slow motion to see exactly what was going on. When we started, the balls were mostly going line drive, 75 feet out. After watching some slow-motion video it was pretty apparent that the sling was releasing way to late. So we bent the nail way back until we got it just right. This actually accounted for about a 100-foot increase in distance.

Another really nice improvement we made was make a new sling. We cut a big square out of some stiff denim pants, also bound for Good Will. We attached the sling at four points to the rope, rather than just two. This turned out to be a lot more consistent than the design we found on the original trebuchet plans.

After all the mechanics where tweaked we added a giant rock that Brian went hunting for around the park. The rock added quite a bit of weight to the bucket. So much so that the bucket started scraping the ground whenever it came down, and eventually bent the rod so much that it broke off. Next time we'll have to reinforce the hanger better.

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