Rapid City has one. Who knew? We were mostly interested in the Pumpkin Chucking – accomplished via trebuchet. There were six contending teams. Four from the School of Mines, one from Spearfish High School, and one from a Middle School. The biggest surprise: The high school (blue one) and middle school (bare lumber one to the right of the blue one) teams basically tied for third place.
The one on the left was the clear (very, very clear) winner. It is from the robotics club at the School of Mines. Weights drop, raising that blue arm, which hits a stop and launches the pumpkin. Most of it is framework to keep it from tipping over or flying apart.
The coolest looking one is from the metal club at School of Mines:
It uses angular momentum generated by cranking it to fling its projectile. It worked OK, but not great. The high school one used a “lawn-mower start” type rope pull to unwind. I think the release mechanism was what made that work better more than the “where momentum comes from” difference.
A few from the side:
Note to self: If I wish to besiege someone, use a gravity driven trebuchet. The spinning ones did not do well.
This post would not be complete without a shout-out to the bouncy “castle” setup. Wow! Those things were impressive – but not enough to take a picture. Lots of food vendors and the typical street fair booths were there, too. Surprisingly, we didn’t buy anything.