Catapults are example of war machines where people were able to use very limited math and physician knowledge in very sophisticated way, in order to kill another people. Exact knowledge was substituted by personal experience resulting in variety of catapult types. So we know Hellenic ballista, Roman onagers, medieval trebuchets, mangonels etc...
Trebuchet is most often made in these days as attraction for tourists in medieval castles, probably because it does not rely on elastic components, hence does not degrade so fast with time. Despite I have seen few catapults when visiting castles, I have never seen one in operation.
I made simple, little, trebuchet-type catapult. As it is little, many simplifications are possible, e.g. I do not need lock for "fire" or winch. It is possible to "fire" catapult by hand.

So let's go:
Frame of catapult is made from wooden plate with two 5x5 sticks (40cm length) screwed together (see left part of chart).
Shelf for sinkstone is nailed from one squared log and two little plates (see left part of chart).


Dimensions are given in centimeters.

Hurling Lever is from bamboo stick of 1m length. It turns on pivot (referred to as "wire" in chart). Shelf for sinkstone is linked to Hurling Lever by cord:





Sling is made from two cords and wrapper for pebbles:

• one cord is bound on top of Hurling Lever permanently.
  
• second cord is finished by washer and hanged on little hook, so it can be released in right moment. Curve of hook needs to be tested and adjusted by nippers each time when weight of sinkstone changes:
  
  
• I made wrapper from wired frame sewn into piece of fabric:
  
  

All parts are mounted together:



and sinkstone, of four cobble-stones, is loaded:




And here is how this trebuchet operates:


If you don't see video, click here.


Firing range is approx. 15 meters with 4 cobble-stones and approx. 40 meters with 8 cobble-stones.

Enjoy, but don't hurt your neighbour!

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