Saturday, September 29, 2018

Let's Get Ready to Hurl - Trebuchets On Your Mark

It is now less than 24 hours to go until our 10th Annual Vermont Pumpkin Chuckin' Festival kicks off Sunday, Sept. 30th, at Stoweflake Mountain Resort (11am - 4pm).

Just a reminder now of how much work goes into building a quality trebuchet. Here is a high level trebuchet build in four videos by tech Youtuber Tom Stanton (124,782 subscribers) that was posted over on the website, enjoy:

Trebucheting Tennis Balls at 124 MPH
A trebuchet is one of the older machines of war. It’s basically a sling on a frame, with a weight that you can lift up high and which pulls the sling arm over on release. Making one opens up the doors to backyard mayhem, but optimizing one opens up the wonders of physics.

[Tom Stanton] covers just about everything you need to know about trebuchet building in his four-part video series. Indeed, he sums it up in video two: you’ve got some potential energy in the weight, and you want to transfer as much of that as possible to the ball. This implies that the optimal path for the weight would be straight down, but then there’s the axle in the way. The rest, as they say, is mechanical engineering...

Video three was the most interesting... [Tom] already had some strange arm design that intends to get the weight partially around the axle, but he’s still getting low efficiencies, so he builds a trebuchet on wheels — the classic solution. Along the way, he takes a ton of measurements with Physlets Tracker, which does video analysis to extract physical measurements. That tip alone is worth the price of admission, but when the ball tops out at 124 mph, you gotta cheer.

In video four, [Tom] plays around with the weight of the projectile and discovers that he’s putting spin on his tennis ball, making it curve in flight. Who knew? 

A picture of a War Machine getting loaded up to come to our 10th Annual Vermont Pumpkin Chuckin' Festival:

Heavyweight Trebuchet gets loaded up to come to 10th VTPC