How To Build A Catapult Out Of Wood

How to Build a Catapult Out of Wood


This is a fun and unique project that you and your family and friends will surely enjoy. This guide will show you how to make a catapult out of wood. A catapult is a fun device that can hurl anything to the air to land at a distance.

You can use your own catapult to play with friends. You can throw all kinds of things like balls, rocks, pumpkins or watermelons. This is quite easy to do and you and your family can make this just in time for a special occasion or family event.

Catapult building basics

To be able to construct a catapult successfully, you need to use only the best materials and use the best tools. Follow this guide to the T and soon you will have your own catapult to play with.

Things you’ll need

  • Broomstick or crank
  • Padding
  • Plywood (1/4″ to 1/2″ thick, 15″ by 18 and 1/2″)
  • Rope (strong, stretchy preferred, like a kernmantle rope)
  • Screws or bolts
  • Weights (optional)
  • Wood (preferably non-flexible, like oak wood)
  • If using 2×4 planks – two pieces at 36″, one piece at 30″, four pieces at 15″, and one piece at 18″


1) Forming the base

Forming The Base


Form the base by positioning the 36″ 2×4 flat wood in an elongated manner on your workbench or on any stable surface. Place your 18″ 2×4 at a right angle to the 36″ piece at 15″ from the end of the 36″ piece. Screw these planks of wood in place.

Construct the plywood triangle. Place this on top of the planks. The 18″ side of the plywood will be vertical to the 36″ plank. The base will be parallel with the 36″ plank. The diagonal will be approximately spanning the distance in between the two ends of each 2×4 plank. Screw down the triangle to the 2x4s. This creates one base leg of the catapult.

Next, construct the left side of the base and fasten the other triangular plywood piece. Do this in the same way you constructed the right side.

Connect the left and right sides with the base of the triangle and base of the 36″ 2×4 forming the bottom of the base. The hypotenuse will face up. Assemble everything using long screws to ensure your frame is sturdy.

2) Forming the arm

Forming The Arm

Screw a cross brace between the two sides. The top of the cross brace should be level with the top of the vertical 18″ 2×4 boards. Use your 30″ 2×4 and measure 2.5″ from one end. Drill a centered hole on the narrow side of the board through the entire width. Place a cup or launching basket. You may also use bowls and cases. Experiment on different objects.

Drill a hole in the base. This hole will be centered 6″ from the end of the 36″ piece where the end of your plywood triangle is found. Then measure 2.5″ from the bottom edge and drill. Pad the arm using a blanket or several layers of wrapped cloth. This will prevent your catapult from damaging itself when the arm is pulled back and comes in contact with the cross brace.

3) Lacing the arm

Lacing The Arm

Lace about 20′ of rope around a broomstick handle, then take it this to the hole in the right side of the base, through the hole drilled in the arm of the catapult, to the other side of the base and back to the second broomstick handle.

Loop the rope around the second handle, and then take it back through the frame to the first handle. Do this several times. Knot the end of the cord to the side of the arm. Add a catch for the throwing arm. As you twist your handles, the torsion of the rope will make the throwing arm ascend until its tension holds it near the cross brace. Let the arms restfully back in the launching position; this way you can tell where is the best place to install your catch.

Place an object in the basket to arm your catapult and apply torsion. Turn the handles to create torsion in the rope. This will provide the catapult tension. Add a payload to your cup, wind your broomstick cranks, release the catch and fire to launch the object to the air.


A catapult may be a bit difficult to design and construct but no doubt this is a good family project that you can do in a weekend. Learning how to build a catapult lets you work on various projects of varying degrees of difficulty in the future.