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Quick Release Trigger Plans

The quick release trigger was designed for use on the Melon Felon. We had the problem here of needing a trigger, but using a simple screw-eye and pin arrangement was not going to work with a 300 pound counterweight, or an approximately 80 pound load at the trigger. So, we had a jury-rigged solution initially, but this failed to trigger constantly, so we looked for other ideas. We did not want to have to purchase a manufactured quick release, as they can be expensive, and we didn't need a hugely strong mechanism. At The Hurl, we found plans for a simple quick release that Ted had designed. Lacking a good set of plans, we took his pictures and made up our own plans for a trigger. Jason and his dad were to later make it from some scrap metal.

The plans we made this trigger from are available here in PDF format. Just one thing to note, the tolerances are stated as ±0.001 inches. Now this is not really necessary for this trigger. In reality, the tolerances are "as close as you can get to the dimensions given." The tolerances there are from a standard drawing format we use for other pursuits.

The trigger is designed to be made from ¼" thick steel, and as such will be able to operate under a fairly heavy load. The other nice thing about this design is that under load, the trigger actually gets pushed shut and will not fire unless pulled. Also, the trigger is easily rigged in such a way that a line can be tied to the release and pulled from the side, the safest place to trigger a trebuchet from.

Quick Release Trigger Plans (.pdf, 95KB)

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Use "common sense" when operating trebuchets and catapults. Even little ones can be dangerous. Do not place anything you are not willing to lose in the plane of the arm rotation (this includes yourself, body parts, car windshields, cameras, etc). These catapults and trebuchets are capable of throwing just as far backwards as forwards, and the use of a backstop of some sort is recommended, though the use of one does not make the region behind it safe.

Also, just because the throw got away safely downrange does not mean the end of the danger. The arm is likely still swinging wildly along with the counterweight, and there is a sling whipping around. One thing many people fail to take into account is this sling; some people put a metal ring on the slip end of the sling and this ring can HURT when whipping around!

Have fun hurling, but please KEEP IT SAFE!!!