For one of our 25 Days of Christmas activities, we made this catapult. The original pin we saw used jumbo Popsicle sticks, but I didn't have any of those. We used regular size Popsicle sticks and they worked great. I hot glued on a little disposable cup to hold the pom poms and marshmallows we were shooting. The kids had a blast!
Make sure the rubber band that hold the two sticks in the front together isn't too tight. There are 8 Popsicle sticks in the middle bunch. The green one that you see in the picture is stuck between the bottom two sticks from the pile of eight.