I forgot to introduce myself earlier, but here I am. I live in Pennsylvania in the USA. My education is mostly in mathematics and physics, and I am an avid shooter. I do some hunting as well. Since I live in the country, I have lots of need and opportunity to tinker. So, with my knowledge of physics and experience with ballistics, combined with a tinkering spirit, slingshot building is a natural fit for me. Thanks to everyone for forming such a nice community, and thanks especially to Joerg for bringing us all together. Also, thanks to Thomas Kole and any others whose work allowed us to do this on the Internet.