Please add us to the list of satisfied customers who have constructed the marshmallow catapult originally seen in the May 2010 issue of Family Fun magazine! This popular project delighted the boys last week when we sat down to make them for the purpose of flinging marshmallows to intercept by mouth. Okay...that particular part was not a success! But we were amazed at how far and how fast those projectiles flew, learning that the amount of rubber band tension determined velocity.
Adequate instructions are provided at the above link, but there are a few things I would do differently. The "family size" tissue box was a little flimsy even though the width and depth worked perfectly. I think I'd reinforce the long sides with cardboard next time, or possibly substitute a shoe box.
My grandsons are five years old and quite experienced with crafty and scientific enrichment projects provided at home by their parents, yet I did much of the work on our catapults. Rubber bands must be twisted and tied tightly and holes punched accurately - best done by an adult. The kids enjoyed measuring and observing though, picking up a few related terms as they watched and waited.
As always, grandma learned some new things too. The device made wonderful entertainment for the boys' cats, "Marshall" and "Baby." I probably should have anticipated that one! But then there were the sound effects - loud and lusty shouts of "Fire in the hole!" as ammunition was positioned for launch. I suspect that has something to do with the fascination little boys have with historic weaponry, anything set up to shoot far and fast, controlled, aimed and fired by a pair of youthful engineers whose curiosity and enthusiasm keep this grandma coming back again and again to enjoy more and more of the same!