How To Build A Trebuchet

Here are plans and pictures on how to build this medieval trebuchet. It is a siege engine that wreaked havoc in the middle ages and you can make this small 12 inch table top version with materials from around the house. Building this catapult-like weapon is easy and you can do it in a couple of hours. Without any tweaking or modifications this trebuchet launches a clay ball thirty feet. It is adjustable in several ways and you can build it to launch projectiles even further.

Here is a quicktime movie of this Trebuchet firing off

 Trebuchet Movie

The Little Dragon Trebuchet - This Trebuchet Build Plan will take you about two hours to complete. Here is a parts list for easy printing

Trebuchets Built By Web Visitors

Is it possible to build this trebuchet successfully? It sure is! A web visitor has built one, and taken pictures. He has also made a nice little design improvement to it. His treb has a neat little locking bar so you can lock it in the ready position then pull the pin to fire it off. You can see pictures of his Trebuchet and his design improvement here.

Another great trebuchet project submitted by a web visitor. This treb is a big success and the builder has done some great research that will help you build an even better trebuchet! He also carefully explains the optimal weight ratio between the counterweight and the projectile Check it out here for some great tips and information

Here is a neat little project that somebody made (Adil). He made his trebuchet at half the size of the project here. And he did a little modification. Instead of using the long string and pouch he used a spoon to hold the projectile -- this is similar to how an Onager works. Nice work on this little trebuchet project -- it shows some good improvisation. He also made a little castle to assault with his siege engine and he created two videos that you can watch here Mini Trebuchet Project If you are having trouble with your trebuchet string and pouch these videos show a nice alternative. If you want to make a smaller one you should check this one out.

Here is another trebuchet that a web visitor built. It is by Gabe C. I call this one the Ferrari of Trebuchets because of the excellent custom paint job including flames! Gabe also made a couple of very nice improvements on my design that you might want to check out. Gabe C's Trebuchet

What You Need

The Recommended Tools for this project

Hammer Saw Screwdriver Pliers (needlenose) Wood Glue File Scissors Drill and Bits Sandpaper Cutters for metal

Most of these tools are just recommended and you can vary the tools depending on what types of materials you use for this project. Here are some tips: Needle nose pliers are best for manipulating small parts but if you don't have any then any other type of pliers will be fine. The metal file shown in the center of the picture is recommended any time you work with metal - you should always file down cut metal so there are no sharp edges. The sandpaper shown is attached to a block; this makes sanding small parts easy and you should always sand every piece of wood you cut so there are no splinters.

Miscellaneous items needed to Make the Trebuchet

Heavy object (three different ones are shown on the far left) only 1 needed Small screws Small Nails 2 eyehooks wire or bread ties Electrical tape (or masking) 3 feet of string piece of cloth - 6 inches. Paints (optional) 1 sheet of cardpaper -similar to cereal box (shown under the paints)

About the miscellaneous materials: The counterweight is very important and you should find something as heavy as possible. I used a chinese healing ball for my trebuchet but you can use items found around the house like batteries taped together, penny rolls taped together, a lump of heavy clay or even a rock. Special Note: You will also need a metal bar for the cross piece. I will talk more about this a bit later.

Wood Needed for the Project

1 16 inch piece 2 12 inch pieces 2 10 inch pieces 3 5 inch pieces 1 square piece of flat wood about 5-6 inches

About the wood: The wood I used is about one inch by one half inch thick. You can be very flexible with this and use almost anything similar. You can cut strips of wood if you need to. The sheet of wood shown is important for strength and it is about one quarter inch thick but thinner would be ok.

Okay! This is everything you need to make this table top Medieval Siege Weapon. Let's start with the building instructions.

I lot of people are building this Trebuchet and I get a lot of email about it. One of the common questions is about my counterweight. Seeing as I use a solid metal Chinese Healing Ball it makes quite a difference and not everybody has these. So to get an idea of how much one of these balls weighs I made up a little scale and weighed the ball with pennies. It comes out to 147 pennies. This gives you a good idea of what to shoot for with your counter weight. If you use three rolls of pennies your weight is about the same as mine.

It was a kooky contraption I built but a nice little project: see the scale I made to weigh my counterweight

Lets continue on and start building this Trebuchet

BOOKS

Want to build a bigger, better, more powerful or fancier siege engine? There are some great books available to you. These books, available at Amazon.com, will help take your trebuchet or catapult building to new heights! Pun intended!

The Art of the Catapult: Build Greek Ballistae, Roman Onagers, English Trebuchets, and More Ancient Artillery - Nice book that shows you how to build ten different catapult projects, moderate wood working and pvc piping kind of stuff. Good book with complete instructions and materials lists.

Buy from Amazon.com: The Art of the Catapult: Build Greek Ballistae, Roman Onagers, English Trebuchets, and More Ancient Artillery

Backyard Ballistics: Build Potato Cannons, Paper Match Rockets, Cincinnati Fire Kites, Tennis Ball Mortars, and More Dynamite Devices Want to get a little more creative? This book is off the hook!

Buy From Amazon.com Backyard Ballistics: Build Potato Cannons, Paper Match Rockets, Cincinnati Fire Kites, Tennis Ball Mortars, and More Dynamite Devices

Whoosh Boom Splat: The Garage Warrior's Guide to Building Projectile Shooters

These are the homemade machines that you've dreamed of building, from the high-voltage Night Lighter 36 spud gun to the Jam Jar Jet, the Marshmallow Shooter, and the Yagua Blowgun. Including detailed diagrams and supply lists, Gurstelle's simple, step-by-step instructions help workshop warriors at any skill level achieve impressively powerful results.

Adventures from the Technology Underground: Catapults, Pulsejets, Rail Guns, Flamethrowers, Tesla Coils, Air Cannons, and the Garage Warriors Who Love Them

Sneaky Uses for Everyday Things: How to Turn a Penny into a Radio, Make a Flood Alarm with an Aspirin, Change Milk into Plastic, Extract Water and Electricity ... a TV with Your Ring, and Other Amazing Feats

Gonzo Gizmos: Projects & Devices to Channel Your Inner Geek - It's possible to use optics to roast a hot dog without electricity or a stove; to make a simple radio with just an iron, a few basic circuits and three shiny pennies; and to assemble a simple steam-powered boat with a plastic bottle, a candle, copper tubing and a nail. Of course, only die-hard science nerds would attempt these projects.

Siege Engine Kits and Projects

Looking for a complete kit to build a trebuchet?

Edmund Scientific has a great trebuchet kit that you can put together and use. The Build your own trebuchet kit

Amazon.com has lots of Trebuchet Kits you can build

Le Toy Van TV361 Edix The Medieval Village - Trebuchet

Features The Le Toy Van Trebuchet is an excellent addition to any Le Toy Van castle or Papo castle playset. Wind up action Elastic firing system Pre-assembled Painted wooden trebuchet Scaled to complement our castles. Figures not included Ages: 4+

Floating Arm Trebuchet

Great for science projects.

• Converts potential energy into kinetic energy.
• Can hurl a golf ball 200 feet.
• Precision crafted of high quality hardwood.
• Designed and made in the USA for better quality, better performance!

Engineered using modern mechanical principles and computer aided design, this mini-powerhouse can hurl a golf ball over 200 feet. It uses guillotine action and a plunging beam to maximize potential energy and a floating arm to convert that energy into projectile motion. Precision crafted of high quality hardwood, the kit contains everything you need to build a working model.* The trebuchet is essentially a gravity powered energy conversion machine - it's a great way to see classical mechanics in action! The completed model stands 34 inches tall, 18 inches long and 7 inches wide (12 inches wide with the included steel counterweight boxes). A common complaint from engineering professors is that "Students today have a great understanding of computers, but fewer and fewer of them have any real hands-on, real-world understanding of physics and mechanics." Our kits are designed and intended to spark an interest in real-world science and engineering, and maybe even a bit of history too! The detailed instructions are complete with diagrams, photos, tuning tips, equations for calculating the machine's efficiency and more! All parts are pre-cut, pre-drilled and can be assembled to a finished model in one evening (plus glue drying time). We've put a lot of time and effort into making this kit as easy and complete as possible. It's a fun way to learn about physics and engineering! WARNING! This is a functional model intended for educational demonstrations of physics. It contains a fast moving arm and projectile that can cause injury if you make contact when firing. Use only under strict, competent adult supervision. * We supply the containers, but you'll need to supply the counterweight material. Anything from nuts and bolts, BBs, coins, sand or a good fist full of pebbles will do! * Can throw 200 feet when properly constructed and tuned with sufficient counterweights. Your performance may vary.

Stirling Warwolf Trebuchet

A highly detailed and historically accurate 1/20th scale trebuchet kit.

• Includes two true scale-sized medieval warrior figures.
• Authentic half-lap and mortise and tenon joinery.
• Over 140 hardwood pieces.
• It really works! Designed and made in the USA for better quality, better performance!

During a siege of Stirling Castle in 1304, Edward Longshanks (Edward the first, King of England) ordered his engineers to make a giant trebuchet for the English army, named "Warwolf". With one blow, Warwolf leveled a section of wall, successfully concluding the siege of Stirling Castle. The Stirling Warwolf is generally thought of as the most powerful and most famous of all the trebuchets in history. With an authentic and historically accurate "squirrel-cage" winch mechanism, block-trolley system and working trigger, frame-ladder (for re-cocking), half-lap and mortise and tenon joinery, this is the most highly detailed and historically accurate trebuchet kit you can get. This kit has well over 140 pieces in it, plus two true scale-sized medieval warrior figures. At 1/20th scale, this machine stands 18 inches tall at the apex. The arm reaches to a height of 32 inches, and hurls its projectiles 40 to 60 feet! At 1/20 scale, that equates to about 800 to 1200 feet for a life-sized model. Even the projectiles (included) are scaled properly to represent 100 lb. and 350 lb. missiles. Highly detailed and computer cut for accuracy, this model is a joy to build. The detailed instructions are complete with diagrams, photos, tuning tips and even historical notes about trebuchets. Tools you will need include glue, a flat file and a 1/4" round or rat-tail file, clamps or rubber bands, household scissors and sandpaper to smooth any rough edges (there shouldn't be many.) The only other things you'll need to supply are a few hours of time, a little effort and some pennies for the counterweight bucket. The kit is made from high-quality white hardwood. It can easily be stained any color, but simple exposure to sunlight will turn the natural wood a rich golden-brown over time. We've put a lot of time and effort into making this kit as easy and complete as possible. We hope you'll enjoy building and operating it as much as we have!

This is a Storm The Castle Project

Table of Contents for this tutorial

1. Materials/Tools
2. Assemble the sides
3. Assemble the base
4. Make and attach the swing arm and counterweight
5. The stringpouch and the runway
6. Finish and fire it!
7. Trebuchet video (quicktime MOV)
8. Books/Buy
9. Free Trebuchet Plan
10. Weighing the counterweights
11. Johns Engineering info about Trebuchets
12. Koji's Locking mechanism
13. Adil's mini Trebuchet
14. Gabe's Ferrari of Trebuchets
15. Trebuchet Videos