I’ve built my share of catapults (see MAKE Volume 28, “Gravity Catapult”), and this floating-arm kit has thoroughly impressed me. The parts come pre-cut in solid ash, and you clip off tabs to remove them, just like the plastic models I built as a kid. A file will help clean up the tabs.
It’s put together with wood glue, so use one with good tack or you’ll do a lot of waiting. The instructions call for two clamps, but you’d be much better off with eight or more. Spring clamps provide suitable force and won’t mark up your wood parts.
After all your satisfying work, you end up with an impressive 34-inch trebuchet, capable of hurling a small, dense projectile a respectable 200 feet!