Its me postmahomeson aka timster postma
I have been gone for a while , advocating for the will of the future last summer as my own version which called the creative libertarians
But im back now so last christmas 2015 i got a 3d printer for christmas its a lulzbot mini
So yes all the designs i currently since then that have been publish have been tested ,
Below is the links to the catapult note it is high impact application

Https://goo.gl/BiFj5K
3dsha.re/product/easy-catapult-shooter/

( shell shooter version 31.5 caliber )

My mini factory
( improvised ammo shooter)

https://www.myminifactory.com/object...-shooter-19482