If you plan to use your trebuchet indoors, you’ll want to make a small trebuchet. You can make a wooden trebuchet with a base about 12 inches (30 cm) and a swing arm of about 16 inches (40 cm) or a smaller and lighter model out of popsicle sticks. {“smallUrl”:“https://www. wikihow. com/images/thumb/2/2d/Build-a-Trebuchet-Step-1Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-1Bullet1. jpg”,“bigUrl”:"/images/thumb/2/2d/Build-a-Trebuchet-Step-1Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-1Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} If you plan to use your trebuchet outdoors, you’ll want to make a larger trebuchet. A backyard trebuchet could be made of wood or PVC pipe with a 24-inch (60 cm) base and a 32-inch (80 cm) swing arm. A trebuchet to demonstrate at a Renaissance faire could be several times larger than this, if you have sufficient space to launch its projectiles, but you’d have to design it to be taken apart for transport and reassembled on site unless you have a pickup or trailer to haul it around in. {“smallUrl”:“https://www. wikihow. com/images/thumb/c/c4/Build-a-Trebuchet-Step-1Bullet2. jpg/v4-460px-Build-a-Trebuchet-Step-1Bullet2. jpg”,“bigUrl”:"/images/thumb/c/c4/Build-a-Trebuchet-Step-1Bullet2. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-1Bullet2. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} The instructions in the section “Building Your Trebuchet” are written for building a trebuchet using pieces of wood. You can adapt them to whatever building material you choose to use. {“smallUrl”:“https://www. wikihow. com/images/thumb/f/f8/Build-a-Trebuchet-Step-1Bullet3. jpg/v4-460px-Build-a-Trebuchet-Step-1Bullet3. jpg”,“bigUrl”:"/images/thumb/f/f8/Build-a-Trebuchet-Step-1Bullet3. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-1Bullet3. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"}
An indoor trebuchet could launch grapes, paper wads, or Nerf balls, while an outdoor trebuchet could launch water balloons, tennis balls (perfect for Renfaire mixed doubles), golf balls (for Renfaire golf), clay balls, ball bearings, croquet balls, billiard balls, or even actual rocks. (Medieval trebuchets launched not only rocks, but also chunks of burning pitch and dead horse carcasses, a Middle Ages form of chemical warfare. ) {“smallUrl”:“https://www. wikihow. com/images/thumb/2/2d/Build-a-Trebuchet-Step-2Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-2Bullet1. jpg”,“bigUrl”:"/images/thumb/2/2d/Build-a-Trebuchet-Step-2Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-2Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} Whatever you decide you want to launch with your trebuchet, your counterweight should be from 100 to 133 times the weight of your projectile. [3] X Research source If you want to launch items of various weights, you can set up your trebuchet with a bucket or bag to hold and adjust the counterweight. (If you use a bucket, its weight forms part of the overall counterweight. ) {“smallUrl”:“https://www. wikihow. com/images/thumb/0/04/Build-a-Trebuchet-Step-2Bullet2. jpg/v4-460px-Build-a-Trebuchet-Step-2Bullet2. jpg”,“bigUrl”:"/images/thumb/0/04/Build-a-Trebuchet-Step-2Bullet2. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-2Bullet2. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"}
Two long base pieces. For a small trebuchet, you may want to make them 1 foot (30 cm) long; for a larger trebuchet, they can be longer. {“smallUrl”:“https://www. wikihow. com/images/thumb/0/09/Build-a-Trebuchet-Step-3Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-3Bullet1. jpg”,“bigUrl”:"/images/thumb/0/09/Build-a-Trebuchet-Step-3Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-3Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} Two uprights. These should be about 5/6 the length of the base pieces or as long as the base pieces, but no longer. If you made the long base pieces 1 foot (30 cm) long, they would be 10 to 12 inches (24 to 30 cm) long. {“smallUrl”:“https://www. wikihow. com/images/thumb/3/33/Build-a-Trebuchet-Step-3Bullet2. jpg/v4-460px-Build-a-Trebuchet-Step-3Bullet2. jpg”,“bigUrl”:"/images/thumb/3/33/Build-a-Trebuchet-Step-3Bullet2. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-3Bullet2. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} Three cross pieces. These can be 1/2 the length of either the uprights or of the long base pieces. You want the trebuchet to be fairly narrow to ensure that it throws its projectiles in a straight line. {“smallUrl”:“https://www. wikihow. com/images/thumb/4/40/Build-a-Trebuchet-Step-3Bullet3. jpg/v4-460px-Build-a-Trebuchet-Step-3Bullet3. jpg”,“bigUrl”:"/images/thumb/4/40/Build-a-Trebuchet-Step-3Bullet3. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-3Bullet3. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} One swing arm, or beam. [4] X Research source This piece should be 1 1/3 times the length of the base pieces; if the base pieces are 1 foot (30 cm) long, the swing arm should be 16 inches (40 cm) long. [5] X Research source {“smallUrl”:“https://www. wikihow. com/images/thumb/7/7b/Build-a-Trebuchet-Step-3Bullet4. jpg/v4-460px-Build-a-Trebuchet-Step-3Bullet4. jpg”,“bigUrl”:"/images/thumb/7/7b/Build-a-Trebuchet-Step-3Bullet4. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-3Bullet4. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"}
If you prefer, you can design the support braces to look like isosceles triangles so that they will slope on both sides of the uprights when assembled.
A piece of rebar would make the strongest axle, but you can also use a screwdriver blade or the axle from a wheeled garbage can. For a small enough trebuchet, you can use the axle from a toy car. When you decide what to use as your axle, measure its diameter.
Repeat this process for the other assembled piece and brace, but this time point the long end of the base and the brace’s hypotenuse in the other direction. {“smallUrl”:“https://www. wikihow. com/images/thumb/2/21/Build-a-Trebuchet-Step-7Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-7Bullet1. jpg”,“bigUrl”:"/images/thumb/2/21/Build-a-Trebuchet-Step-7Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-7Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} For a large trebuchet, you may instead want to cut lengths of planking to serve as braces instead of using plywood sheeting, and either cut the edges at an angle or use two pieces on each side to make a rectangular brace. [8] X Research source {“smallUrl”:“https://www. wikihow. com/images/thumb/e/ef/Build-a-Trebuchet-Step-7Bullet2. jpg/v4-460px-Build-a-Trebuchet-Step-7Bullet2. jpg”,“bigUrl”:"/images/thumb/e/ef/Build-a-Trebuchet-Step-7Bullet2. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-7Bullet2. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"}
Mark the drill holes about 1/10 of the way down from the top. You’ll want to use a drill bit that’s the same diameter or only slightly larger than the diameter of the axle.
When drilling holes through the swing arm, use the bit the next diameter larger than that of the axle or possibly even 2 sizes larger. The swing arm should turn freely on the axle without wobbling. {“smallUrl”:“https://www. wikihow. com/images/thumb/a/ae/Build-a-Trebuchet-Step-9Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-9Bullet1. jpg”,“bigUrl”:"/images/thumb/a/ae/Build-a-Trebuchet-Step-9Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-9Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} Space the secondary holes out far enough that they won’t break out and form a larger hole would allow the swing arm to slip if threaded through it.
The eye hook for the sling will go on the end furthest from where you drilled the holes. It should be open to serve as a release pin,[9] X Research source allowing one end of the sling to open and allow the swing arm to hurl the projectile forward. To keep the sling from opening too soon, drive a nail into the end, partially covering the release pin. Cut the head off the nail to keep the sling from catching. [10] X Research source {“smallUrl”:“https://www. wikihow. com/images/thumb/d/d4/Build-a-Trebuchet-Step-10Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-10Bullet1. jpg”,“bigUrl”:"/images/thumb/d/d4/Build-a-Trebuchet-Step-10Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-10Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} The eye hook for the counterweight should be closed, unless you plan to change the counterweight often. Even then, you may want to attach a carabiner or split ring to the counterweight eye hook. {“smallUrl”:“https://www. wikihow. com/images/thumb/8/81/Build-a-Trebuchet-Step-10Bullet2. jpg/v4-460px-Build-a-Trebuchet-Step-10Bullet2. jpg”,“bigUrl”:"/images/thumb/8/81/Build-a-Trebuchet-Step-10Bullet2. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-10Bullet2. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"}
For a tabletop trebuchet, you may want to attach a piece of posterboard or cardboard to the bottom of the frame to protect the surface the trebuchet rests on when firing it. [11] X Research source
The throwing side of the swing arm should rest on the short side of the trebuchet frame because the force generated when it moves will thrust the frame downward. If this thrust falls on the short side of the frame, it could pitch the trebuchet forward. {“smallUrl”:“https://www. wikihow. com/images/thumb/3/38/Build-a-Trebuchet-Step-12Bullet1. jpg/v4-460px-Build-a-Trebuchet-Step-12Bullet1. jpg”,“bigUrl”:"/images/thumb/3/38/Build-a-Trebuchet-Step-12Bullet1. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-12Bullet1. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} The nail should be pointing up to ensure that the sling will open without coming off the swing arm entirely. {“smallUrl”:“https://www. wikihow. com/images/thumb/a/a1/Build-a-Trebuchet-Step-12Bullet2. jpg/v4-460px-Build-a-Trebuchet-Step-12Bullet2. jpg”,“bigUrl”:"/images/thumb/a/a1/Build-a-Trebuchet-Step-12Bullet2. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-12Bullet2. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"} If the axle extends past the frame, you may wish to affix cotter pins or caps to its ends to keep it from slipping out when you launch projectiles. {“smallUrl”:“https://www. wikihow. com/images/thumb/1/17/Build-a-Trebuchet-Step-12Bullet3. jpg/v4-460px-Build-a-Trebuchet-Step-12Bullet3. jpg”,“bigUrl”:"/images/thumb/1/17/Build-a-Trebuchet-Step-12Bullet3. jpg/aid4325264-v4-728px-Build-a-Trebuchet-Step-12Bullet3. jpg",“smallWidth”:460,“smallHeight”:345,“bigWidth”:728,“bigHeight”:546,“licensing”:"<div class="mw-parser-output">
License: <a target="_blank" rel="nofollow noreferrer noopener" class="external text" href="https://creativecommons.
org/licenses/by-nc-sa/3.
0/">Creative Commons</a>
\n</p>
<br />\n</p></div>"}
If you like, you can tie the string holding the sling to the trebuchet directly to the hook and tie the other end to a loop of thin wire to make it easier to slide off the hook when launching the projectile. You can also tie both string ends to wire loops to make it easier to put the sling on and remove it from the hook.
If your trebuchet releases the projectile too soon, the projectile could fly upward or even backward. If it releases too late, the projectile will slam into the ground in front of the trebuchet. You can control the point at which the sling opens and the projectile releases by bending the release pin nail: bend it more if the projectile flies too high and bend it less if the projectile flies too low. [13] X Research source If you have trouble with the trebuchet releasing the projectile at the right time, you can adjust the weight of the counterweight or remount the swing arm through a different hole.
