Levers of Destruction! Trebuchets, Catapults and Jaws!

This "lesson" was specifically targeting the Nova Engineering Module. As an engineer, I'm a little disappointed they focused solely on levers, so I tried to make it as interesting as possible.  When you're dealing with kids age 6-11, destruction makes things interesting!  We were able to review the three types of lever, while having a snack and shooting paper balls and ping pong balls.


See the file for pictures you can download.  I held them up and had the group label the load, fulcrum and effort.

The attached file gives more details on the different types of levers.  For an intro, talked about how our jaws can be 2nd or 3rd class, depending on whether we're biting or chewing.  Then, we used spoons to flick paper balls for our 3rd class levers.  Then, we brought out the big guns, so to speak.

I built the trebuchet based on the plans from Shultz Engineering.  I love that trebuchet! We were launching ping pong balls across the elementary school cafeteria.  I even brought it to work for the engineering sponsored Fun Team Activity.  I had the Engineering Director on his hands and knees trying to get the aim *just* right.  If you do this activity around Halloween, use the Pumpkin Chunkin' competition as a tie in.

A few notes on the Shultz plan:

• The lock nuts (nylocks) didn't work for me, I couldn't thread them onto the rod. What I ended up doing is more of what you see in the picture at the end, where it was a series of washers and nuts.  
• I used a small water bottle filled with nuts and bolts for ballast, which worked much better than water. 
• My base was a bit different in size, since I just used some wood we had lying around in the basement. The angled support stirrers crossed, but it still worked fine.

I had the trebuchet drilled and assembled at home then took it apart to allow the Webelos to assemble it for credit towards the Engineer Activity Badge.  They just screwed the legs to the base and threaded the rod through the pre-assembled arm.  

Overall, it cost me about $10 for the one trebuchet, but would have cost $14 if I made two (so, $7 each), based on how some of the items were packaged.  Still, $7 for a awesome toy weapon engineering activity, is pretty good.