After returning from Europe, I decided that medieval siege weapons were much cooler than those of today. A friend and I had previously built a (sort of) working trebuchet, but we could only launch one brick about 5 feet before the thing colapsed upon itself. However, with a new found interest, and a book of pictures, we went about designing a new and improved trebuchet.
Update: The Trebuchet made a new record of 234 feet, and at the same time broke! But I hear it’s all better. See the bottom of the page for the pictures of the damage.
As you may have noticed, most of the projects on this site seem to have been made with as little money as possible. This was the case here. The original trebuchet (we’re now in the 3rd build) was crafted with a bucket and the duct tape, asagging too-small rod, etc. The 2×4’s in the boom and the stand happened to be the only so-called “professional” matterials in the whole project. The cross braces were wooden stakes, the cradle was an old feed bag, the rope was as far as I can tell from one of those cheap volley ball nets. But hey, it worked. The latest version, however, is a bit better. Real wood is used, as well as a very strong cross rod. Standing over 24 feet tall, it’s truly a work of art.
The principle of the trebuchet is simple: a weight on one end will make the other end lift, and inertia will cary whatever was there forward. It is much like a catapult, except that rather than storing energy in a bent tree, we store it in the process of lifting the weight up. The weight goes on the shorter end, so the other end swings faster. Our weight was a spackle bucket filled with rocks, coal, and water. (Don’t get the idea that coal is amazing for this purpose; my friend simply had some lying around.)
Though not attached in the picture, there is another peice that adds momentum to the launched object. The sling swings out from underneth during launch, thus adding more inertia. The hook (which the log is sitting on…. it works just to launch stuff by itself.) lets go of one side of the sling at just the right momment (theoretically) so that the object goes flying. We were unable to make our sling detach at the right momment, so we stuck stuff on the hook. However, this is an ongoing project, and it will work sometime soon.
Pictures (Click on any to get the full size!)
The first version! Pretty strange, eh?
Version 1.8 during a launch. (That’s me!)
Version 2. Note the new side bracing:
Version 3! The final and coolest.

And the moment you’ve been waiting for! These are the pics of the damage the took place during a record-breaking 243 foot launch.


Despite a few setbacks, and a lack of good materials the first time, we still made this thing work! As I said, we will continue to work on it. Any crazy ideas, etc, make sure to drop a line by way of email or replies!
Try pumpkins or watermelons. They splash and make a big mess even if they don’t make noise!
I’ll make artillerymen out of you guys yet.
nice treb but id suggest tapering the arm or using graphite but its expensive so oh well pretty far throw for its size : )
Graphite is WAY too expensive….
-Jack
jack [{at}] crepinc.com
http://www.CREPinc.com
instead of using large amounts of courterweight use some large springs. i made one with springs and shot a 1/2 pound 86 yards! it was awesome im thinks about improving this model i made to shoot 8 pound bowling balls. i live in the country so im not worryed about hitsting any houses.
Yes that would make it more efficient, but that would defeat the purpose: this isn’t a catapult, it’s a trebuchet.
Still, yours certainly works well!
Thanks for the input,
-Jack
try burning oil tanks 300Liters.
While I haven’t built one that big (or nice looking) I know what it feels like to have it bust when you think your doing good. I wanted more distance with mine so I “fixed” it, then it shot backwards no matter what I did to it. I gave up, rebuilt it, then it busted bad.
Oh well, I can still cruise the web and look at others’ creations.