Introduction: Trebuchets From Cardboard

This Instructable will show you how to make a Trebuchet from cardboard.

The Trebuchet that was built must of had the following specifications:

1. It had to be made entirely out of cardboard and be waterproof.

2.It has to fit in a 18"x18"x18" box.

3. It must launch an object a distance of at least 30 ft.

Step 1: Materials, Tools, and Safety


1 cardboard box with dimensions of 41"x60"
11" PVC with a diameter of 1"
16" PVC with a diameter of 3/4"
1 bag of mini glue sticks
1 gallon of wood glue
1 yard of string 
at least 1 lb. of weight
1 piece of paper
1 roll of duct tape


1 box cutter
1 yard stick or measuring tape
1 black sharpie
cutting tool (band saw, jigsaw, hacksaw)
1 hot glue gun 
1 drill with 1", and 3/4" drill bit


Make sure that you are wearing gloves and eye protection when handling all tools.

When testing out Trebuchet never aim or fire at people or breakable objects.

Step 2: Cut Out the Base and the Border

1. Measure and trace a 16"x16" area on the cardboard. This is the base of the Trebuchet.

2. Now  draw and cut out 18 3"x16" pieces.

3. With 18 single pieces glue 3 together to have a total of 6 sets of 3. Four of these are going to be used as the outside border and the remaining 2 are what the arm supports will be resting on.

Step 3: Arm Supports

1. Now for the arm supports. On the cardboard draw the outline. the base is 11" long, 4" long at the top, and 15" tall.

2. Make 5 more copies, and glue 3 together so you have a total of 2 sets of 3.

Step 4: The Arm

1. The arm  is 22" tall, has a half a circle diameter of 3" at the bottom, and a 2" half a circle diameter at the top.

2. Once you have the arm done drill a 1" diameter hole 1 1/2" up from the center of the bottom, this is to hole up the basket .

3. Then drill another 1" diameter hole 4 1/2" up from the center of the bottom, this is used to attach the arm to the arm supports.

Step 5: The Basket

1. Next we have to make the basket. Draw on the cardboard a half circle with a diameter of 9". on one end of the flat side draw a line that is 4.5" lone at a 45 degree angle. on the other end draw another line that is 5" long at a 45 degree angle. at the end of those lines draw a 2" line going up. Then connect those 2 lines.

2. Cut out the basket and make another copy.

3. For the bottom of the basket cut out a 5"x13" rectangle. At one end in the center cut out a 2"x2" square for the arm to rest in.

4. Attach the 2 sides of the basket to the bottom.

5.  At the top of the basket drill a 1" diameter hole.

Step 6: PVC Pipes

1. Cut out a length of 6", 3", and 2 1" segments from the 1" diameter PVC.

2. Glue the 2 1" pieces into the holes that are in the arm support.

3. The 6" piece goes into the top hole of the arm.

4. The 3" piece goes into the bottom hole of the arm.

5. Now cut out a 10" segment from the 3/4" PVC. This piece goes into the PVC in the arm support, and into the top PVC of the arm.

6. The remaining 6" goes into the basket PVC, and the bottom PVC of the arm to hold up the basket. 

Step 7: Attaching the Border, Base, and Arm Supports

1. Use the pieces from step 3, and glue them around the edges of the base.

2. Put the remaining two pieces inside and space them about 3" form the sides.

3. Glue the two arm supports on top of the pieces that are inside the border.

Step 8: Attaching the Basket, Sling, and Waterproofing

1. Attach the basket to the arm and attach the arm/basket piece between the arm supports.

2. Fold the paper into a small rectangle, and wrap it in the duct tape.

3. Hot glue the string to the tape and to the top of the arm.

4. After you finish putting everything together spread the wood glue over the Trebuchet to make it waterproof. 

Step 9:

 3 Finally, put different sized weights in the basket and test out your Trebuchet.   

Step 10: Solidworks Assembly and Individual Parts.

Here is the  Solidworks assembly of the Trebuchet and each individual part.