Mini Catapult kit card

So i've been wanting to design for a simple toy that i can give away to my nephews and nieces during our family holiday.. The toy has to be simple to 3d print and easy for the kids to assemble.. And that will entertain them for while.. And it needs to be 3d printed cheap since i have a lot of nieces and nephews.. So i came out with the idea of a catapult that has to be assembled and all the parts will be laid out kinda flat and connected together like those gundam figurines that you have to assemble.. The assemble will be fairly simple following the instructions given.. And you can pretty much catapult anything small.. but to keep it save for the children to play.. i'm gonna use the foam rubber nerf balls as boulder for the catapult..