858 days ago
I built this treb in my basement in an evening. It is constructed of 1x2 pine, ¼ inch steel rod, 1¼ inch deck screws, a few eye bolts, a cotter pin, string, thread and pajama rags. Though somewhat less impressive than it's ancient predecessors, it can still send a one-inch ball of Play-Doh TM about 25 feet.
It could probably throw farther if it weren't for the 8-foot ceilings. The angle of the projectile immediately after the sling opens should be 45 degrees for maximum distance. However, it's set to quite a bit less to avoid hitting the ceiling.