Rotational Joints for cardboard crafting

I have 3 kids and they all love crafting. Cardboard crafting is great because it's basicly free if you bought something or otherwise optained a cardboard box. But since my kids usually have elaborate designs or ideas when it comes to the crafting, it usually leaves me doing all the hard work and I have to come up with clever solutions to make for example rotating parts. It takes longer then needed and once I'm done, it's time to put away all the crafting stuff and clean up.

So I made these to