Well, here it is, my trebuchet, which I call Ludgar. It weights about 600 pounds. I take it from place to place on a trailer. It shoots baseballs, softballs, fruit, water balloons, and more.
People always ask me, "Can I hurl a person?" The answer is "no." It is far too small for that.
For more information on catapults, you can read my new book, The Art of the Catapult. It is available at many bookstores and online. It does not contain how to build information on building catapults as complicated as Ludgar, but it is filled with good ideas for models and smaller projects.
Buy Art of the Catapult There are also some good catapult, air cannon, and othe projects in my book "Backyard Ballistics" as well'
Buy Backyard Ballistics. Lots of good projects including spud guns, air cannons, catapults, and much more