Introduction: Alexander the Great's Macedonian Ballista

Alexander the Great's Macedonian Ballistas, was instrumental in his military campaign through Western Asia, and Northeast Africa. And by age thirty, he had created one of the largest empires of the ancient world, stretching from Greece to Northwestern India. He was never defeated in battle, and is considered one of histories most successful military commanders. The Ballista was an early Greek weapon, which could easily be modified to shoot either heavy darts or spherical stone projectiles. The Greek Ballista was a siege weapon, probably capable of launching projectiles that weighed about ten pounds. But with the decline of the Roman Empire, resources to build and maintain these complex machines became very scarce, so the ballista was replaced by the simpler and cheaper onager. But, luckily for us, these fascinating weapons are still built today, to show people of the ingenuity and resourcefulness of the Greeks and Romans, that came before us.

Today you can build your own small siege weapon, as you head off to war, with Alexander the Great!


  • Miter saw
  • 10 foot piece of 3/4 inch PVC conduit
  • 3 foot long 2x4 with groove running the length of the top
  • 12 foot 2x4
  • Paracord or other nylon rope that can hold a lot of elastic energy
  • 3 inch construction screws
  • 2 inch construction screws
  • Small piece of 1-1/2 inch thick plywood
  • 1/4x 2 inch eye bolt
  • Kreg pocket hole jig and screws
  • Gorilla glue
  • Drill and impact driver
  • 1/2 inch wooden dowel
  • 3/4 inch wooden dowel
  • Bandsaw
  • Stapler
  • Electrical tape

Step 1: Cutting the 2x4s, Wooden Dowels, and PVC

Cut a 3 foot piece of a 2x4, with a groove running the length of it. Then from normal 2x4, cut the Following:

  • (2) 2 foot pieces
  • (1) 7 inch piece
  • (4) 9 inch pieces
  • (4) 12 inch pieces

From the 1/2 inch wooden dowel, cut the following:

  • (4) 2-1/2 inch long pieces

From 3/4 inch PVC pipe, cut the following:

  • (2) 18 inch long pieces
  • (4) 8 inch pieces

Step 2: Building the Stock and Front Frame

Using a Kreg pocket hole jig, screw the 3 foot long 2x4 with the groove in it, to the middle of one of the 2-1/2 foot long 2x4s. Using three inch screws, screw two of the 9 inch pieces to either end of the longer 2x4. Place the remaining two 13 inches in from either end. Place the other 2-1/2 foot long 2x4 on top, and screw in place. You can also add diagonals to the sides of the stock, to strengthen it.

Step 3: Constructing the Back

Screw the seven inch piece to the back end of the 3 foot long 2x4. Take two of the 1 foot long 2x4s, and drill a 3/4 inch hole in each one, 1-1/2 inches from the top. Screw these pieces to the sides of the 7 inch long piece, with the holes protruding 1-1/2 inches above the 7 inch piece. Place the 3/4 inch dowel through the holes, and mount some sort of windlass on it.

Step 4: Drilling the Holes and Adding Handles

On the front, on the middle of each side, drill a 1-1/4 inch hole. Next to the holes, drill a hole, about half way through, 1/2 inch in diameter. Repeat this process on the bottom.

If you would like, add twine handles to the front for easy transportation.

Step 5: Making the Ball Holder

Print out the provided template at twice the width of your 3foot 2x4. Trace the template onto 1-1/2 inch thick plywood and cut out on bandsaw. You may wish to slightly curve the wide side, to better accommodate a spherical projectile. Drill a hole through the back, and screw in a 2 inch long eye bolt.

Step 6: Tensioning the Weapon

To tension the weapon, grab your Paracord, PVC pieces, wooden dowel pieces, and let's get started. To begin have someone hold out their hands, about fifteen inches apart, and wrap the Paracord around their arms about eight times, to form eight long loops. Slide this loop, vertically, through the holes you drilled in the sides of the ballista. Take 2 pieces of 7 inch PVC, and place one in the top, and one through the bottom of the loop ends that are sticking out of the holes. On one end of one of the 18 inch PVC pieces, drill a hole large enough, to thread the Paracord through it. Place this throwing arm in the paracord loops on your ballista. To tension it, twist the short pieces of PVC on the top and, turning it, so that the throwing arm rests against the outside 2x4. Lock the PVC pieces in place, with 2 of the short dowel pieces, that you cut, in step 1.

Repeat the same process, for other side.

To string the ballista, thread a piece of paracord through the holes on either side. Knot the cord on the outside of the throwing arms, so that it doesn't pull out. Staple the middle of the cord, to the back of the ball holder. If you want, you can wrap tape over the staples, for extra assurance that it doesn't come off.

Step 7: Finishing the Back

To finish the back, Make a small wire hook, with a loop on the other end. Attach the wire hook to the eye bolt of the ball holder, and pull a piece of paracord through the loop, until both ends of the paracord touch the rod on the back end of the launcher. Fasten the cord to the dowel, with staples and electrical tape.

Step 8: Firing the Ballista

To fire the ballista, attach the hook to the eye bolt on the ball holder. Crank the windlass back until the ball holder almost touches the dowel. Place a tennis ball in front of the holder piece. Release the hook, and watch your tennis ball fly towards its target! Below, I have provided a short video of me firing the ballista in slow motion.

Step 9: Finished Pictures!

I have provided some pictures of my finished replica. I hope you have enjoyed this instructable!

Make It Fly Speed Challenge

Runner Up in the
Make It Fly Speed Challenge