Last week my family visited the Genghis Khan Exhibit at the Iriving Arts Center. As part of the exhibit, there was a real life size trebuchet and a smaller model catapult made out of wood that the boys could send ping pong balls shooting across the museum.

It was a crowd-pleaser.

Ryan, my 10 year old, made one out of Legos.

The boys own one of the Lego Castle sets that includes a catapult.   Many of the pieces used were from that set.   He has modified that a little to increase projectile distance.   As with all things Lego, modify these instructions to use pieces that you might have at home!

How to Make a Lego Catapult

Step 1:   Construct the base.   The base platform and the catapult foundation consist of these pieces:

Step 2:   Add Lego blocks that allow for arm movement.   The base built from pieces pictured above are on the left.

Step 3:   The base is now complete.   You can see that the two small 2 x 1 stud bricks in between the gold caps are on a rod and can be rotated 360 degrees at this point.   This is where the moving arm will attach.

Step 4:   Build the catapult’s moving arm:

Step 5:   Finish the arm and attach it to the 2 x 1 bricks mentioned above.

Step 6:   Attach a rubber band to launch Lego projectiles across your living room.

The exhibit was calling this type of catapult a trebuchet.

We were wondering what the difference between the two weapons were and after a little internet search which included Wikipedia, this is what I understand to be true:

• Catapult:   A catapult is a mechanical device used to hurl objects.   It is a general term and there are many types of catapults.
• Trebuchet:   A trebuchet is a type of catapult.   The early models were called traction trebuchets and used manpower and ropes to launch a projectile.   Later models used pulleys and counterweights and improved the accuracy of aim significantly.

The type of catapult we just built out of Legos could be described as a traction trebuchet if you imagined the rubber band to be men pulling on ropes.

The Genghis Khan Exhibit will be at the Irving Arts Center through September 2011.   We really enjoyed our visit and it has inspired other kids’ activities and conversations.   This exhibit is a sponsor of this site and provided my family with tickets.