Did you know that you can make a trebuchet out of ordinary office supplies? This is a cool type of catapult used in the Middle Ages as a siege engine. You can build it to amuse yourself when you are bored at work or to ease the stress in your workplace. Just do not let your supervisor catch you doing this, or you might get in trouble.
What you will need:
- Needle nose pliers
- Scissors
- Cellotape
- 8 paperclips
- String or thread
- Blu-tac
- Corrugated card (6×6)
- Batteries (to act as the ballast)
- Rubber band
What you need to do:
The paperclips:
- Using the pliers, straighten out the 8 paperclips.
- On four of the paperclips, make an eyelet that is big enough to insert a paperclip through. Try not to make it too big. On the other end, bend ½” from the edge of the clip at a 90=degree angle to the eyelet. See figure 1.
- Get one paper clip and use it to shape the axle. Curve the two ends into hook shapes – about 2” each or wider than the ballast that you will use. Then go to the exact middle and create a U shape. See figure 2.
- In another paperclip, create a loop that is ½” from the end. Make another eyelet on that same end. On the other end, make a small hook. See figure 3.
- The next paper-clip shape is a bit hard to explain, but it should look like figure 4.
The assembly:
- To assemble them all, take the axle (figure 2) and insert it through the loop of figure 3 (not the eyelet at the end). Wrap Cellotape around the axle on either side of the U shape so the other paper clip will not slide through.
- Get the cardboard and mark the base with a center line that is 6 inches long. Put two lines on each end of the center line.
- On each of the two lines, measure 3” to the left and the right of the center line and mark it with an “X”. You should have 4 X’s. See figure 5.
- Take the 4 paperclips (figure 1) and poke the dog leg ends into the corrugated card where the Xs are. With the dog legs poking straight into the card, the eyelet on the other end should cross over the eyelet end of the other paper clip. The paper clips that should be meeting in the middle should be on the same side of the center line.
- Mount the axle by hooking the two ends through the two meeting eyelets. See photo for reference. Bend the hooks further by using the pliers.
- Secure the whole structure by putting tape over the legs – like making an A-frame. This is to prevent the whole thing from swaying from side to side.
- Take the figure 4 paper clip – this will be the trigger of your trebuchet. Put the end into the card so only the bump and the loop is visible. This should be positioned in such a way so that the loop will be where the center line meets the line with the Xs. This is a bit tricky but make sure it is secure. Put a slit so this trigger can be moved sideways, but not too long so the trigger will not slip out of the card.
- Get the final paperclip and make a little hook and tape it to one of the batteries that you will use as ballast. Get a whole bunch of batteries and attach it to that one battery by wrapping them with a rubber band.
- When assembled, hook the whole thing to the eyelet at the end of the figure 3 paperclip. The ballast should not touch the card base.
The ammo and firing the ammo:
- Create the ammo that you will use to fire from the trebuchet. Take a string and shape it into a loop. Take the free ends of the string and push into a lump of Blu-tac (size of a pea). Wrap the Blu-tac with the string and roll it into a ball. A great length of string should be 2/3s the distance of the hook to the axle (when measured right along the arm).
- Hook the ammo over the arm and pull it down. The hook of the arm should be trapped into the trigger. Position the ammo so it is at the center line and the full extension of the string.
- Aim your little trebuchet and fire by pulling the loop on the trigger towards you. The string of the ammo and the weight of the ballast will have an effect on the flight path.
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