I'm working on building a production animal cracker box. I'm familiar with the flower and bill production boxes from an empty bag and have played with using a ribbon threaded through the pieces as a mechanism to un-collapse the box on production. That works but requires proper technique to snap open the box. I want to make this foolproof so my son can do it, and so am trying to spring load the box. I bought some music wire and am experimenting with a spring design. See attached diagram. It works, but I'm wondering if there is a better way to do this.

My current solution uses a single piece of music wire bent into a complicated shape that forms two arms. The small circle where the ends of the wire meet the horizontal sections represents a small loop so the arm can freely pivot. The "springiness.." comes from the length of wire horizontally twisting as much as from the arm bending down.

A key requirement is that the spring needs to fold flat as the entire box does.

Thoughts?

Click here to view/download attached file.

Looks complicated, but if it works, stick with it. My tendency would be to use a combination of gravity and magnetism to open the box. A magnet in the bottom of the box and beneath the paper sack would pull down on the bottom of the box as you lift it up by the string/ribbon handle.

Karl, I know you are on Facebook. Look for Steve Daly. In his lecture, he was modifying the little production boxes to appear as animal cracker boxes. He may have ideas that can help you.

~michael

On the bottom I use a heavy steel plate for a gravity drop of the bottom of the folded boxes.

Thanks everyone. Thanks Michael for the tip on Steve Daly. Dan that is a great idea to weigh the bottom. THanks.