Around 2015 I became really obsessed with catapults. I made my first catapult using theraband elastic:
This catapult was powerful but too big and not very accurate. The thin elastic is also pretty fragile.
So I made more catapults:
It was interesting to see how much delicate optimization you need to do even for such a simple tool. Here you can see string bindings, and still a relatively large handle.
I started making things smaller:
And later developed simpler and more reliable bindings, using zip ties:
I started a nighttime catapult club called Tottenham Marshes Nighttime Catapult Club (TMNCC).