Tony Goins
UX Professional / Content Manager


If you can't get close to your loved ones, you can still fling ice balls at them.

Problem: We have tennis balls and ice balls just sitting here.

Solution: Trebuchet.

Tools: Research, trial and error, wood, bricks, vinyl.

This was a post grad school project.

I promised myself that if I finished grad school, I was going to build a trebuchet. This ended up being a really nice quarantine project for my son and me. It's powered by four bricks (I started with two bricks, but that wasn't nearly enough power).

It's not really a UX project, although it did require a fair amount of research and planning. It took some trial and error to get it right:

  • Gotta get more bricks.

  • The angle of the nail is key to getting the sling to release at the top of the the swing.

  • Poly-blend cloth is too floppy for the sling - vinyl gets a nice smooth release (I still want to try denim).

  • Gourds are too heavy, at least for four bricks. Tennis balls are ideal.

  • Ice balls are too slippery for the sling, so you have to wrap them in a paper towel or something to get some friction.


You don't want to be on the business end of this thing.