How to Build a Tabletop Trebuchet

A trebuchet was used in the middle ages to either smash masonry walls or throw projectiles over them. They were much like medieval catapults, but much more accurate because of their counterweights. The trebuchet appeared in both Christian and Muslim lands in the twelfth century to aid in siege warfare. They could fling three-hundred pound projectiles over the castle walls and into the enemy stronghold. Even disease infected corpses were flung over castle walls in order to infect the people under siege, rather like an early edition of biological warfare. The twelfth century was not the first time trebuchets appeared in war. China had them in about the 4th century BCE and they were found in Europe in the 6th century BCE. They did not fall out of favor until the invention and use of gunpowder. Today, trebuchets are no longer used in war, but by hobbyists.

Things You'll Need

• Hammer
• Saw
• Screwdriver
• Pliers (needlenose)
• Wood glue
• File
• Scissors
• Drill and bits
• Sandpaper
• Cutters for metal
• Heavy object for counterweight. Use batteries taped together or three penny rolls, a lump of heavy clay or even a rock.
• Small screws
• Small nails
• 2 eyehooks
• Wire or bread ties
• Electrical tape (or masking)
• 3 feet of string
• piece of cloth - 6 inches.
• 1 sheet of cardpaper, similar to cereal box
• Wood about 1 inch x 1/2 inch thick:
• 1 16-inch piece
• 2 12-inch pieces
• 2 10-inch pieces
• 3 5-inch pieces
• 1 square piece of flat wood about 5 to 6 inches

Instructions

1. Cut all the wood first. Cut one16-inch piece, which is the swing arm. Cut two 12-inch pieces for the long base. Cut two 10-inch pieces for the uprights. Cut three 5-inch pieces, as the cross pieces that complete the base.

2. Next cut the triangle support pieces. Cut two identical triangles, easily done by cutting a square in two diagonally. Lay out one 12-inch piece of wood horizontally. Mark a line on it 3 inches from the left end. Place the 10-inch piece of wood vertically at this mark. Now place the triangular piece between these two and glue it in. Nail or screw in it together to make it stronger. Repeat this for the other side of the trebuchet in a mirror image. Mark off 3 inches from the other side of the 12-inch piece of wood and put the upright 10-inch piece and the triangle wood in place. Assemble the base and main frame of the trebuchet. Add crosspieces to the sides. You can now see that this is starting to look like a trebuchet. Glue this together and set it aside to dry.

3. Take the two side pieces you just made and stand them up with the triangle pieces on the outside. Now glue, nail or screw the five inch cross pieces onto them. Mark a dot one inch from the top of each upright. You will be inserting a metal piece across through these holes when you find metal piece that will serve as a sort of axle. Until you find the metal piece, you cannot drill the holes.

4. Find a metal bar that is at least 5 inches long and fairly strong to support the counterweight and the swinging action. You can try a sturdy coat hanger, or maybe the metal handle from a bucket. A blade cut from a long screwdriver might be best. You can even cut the blade off a long screwdriver and use that. But to not insert it yet. You have to make the swinging arm first. The metal swinging arm can be the axle from a toy car or anything close to that. Most household junk drawers hold a round length of metal that you can scrounge and use. When you find the round metal piece you will use, drill the holes to hold it.

5. Assemble the swinging arm. Take the sixteen inch piece of wood and insert a hoop hook in one end then make three marks. Make one three inches from the end, one four inches, and one five inches. Use the drill to drill holes where the marks are. Drill these holes just a little bit bigger than the metal bar you are using, so the wood will turn smoothly. In the other end of the sixteen inch piece insert another hook loop and also insert a nail into the end of the piece at a slight angle. You will make a loop that has to slide easily off this so cut the nail head off. Insert the metal bar through one upright of the trebuchet then run it through the swing arm and then into the other side of the trebuchet. The hook loop at the far end of the arm should be on the bottom of the arm. Ensure the trebuchet arm swings easily with very little friction.

6. Make a counterweight. Tape up your counterweight. Use AA batteries, a stone or three rolls of pennies. The size of the counterweight to should not be larger than a tennis ball. Tape twist ties or wire to the counterweight and then loop it through the loop in the swing arm.

7. Assemble the string and pouch. Cut two pieces of string at least 18 inches long. Fold the cloth in half, then tie each end with a string forming a little pouch. At the end of one of the strings attach a loop. Use wire that is thin yet strong. Now attach the pouch to the arm of the trebuchet. It should be about 12 inches from the hoop. The top loop will slide right off as the arm goes forward. This allows the pouch to open and release the projectile. This string and pouch will rest right under the trebuchet so you need a little runway for it to ride on that you can make out of poster board. Fold up each end and glue the runway into the trebuchet.

8. Fire the trebuchet. Put a projectile in the pouch. A grape makes a good projectile because it can't hurt anything. Put the grape in the pouch and lower the arm of the trebuchet. Run the strings and pouch along the bottom of the runway so they stretch out flat. When you release your finger the arm will swing around and the grape will be thrown forward.