Ryoko found a beautiful Japanese tool for scoring 
cardboard here http://www.pen-info.jp/orita.html, and it inspired us to make our own version with a bicycle gear. I consulted with Ray G, the Exploratorium’s resident bicyclephile and talented gearhead. He came up with this great design. It uses a BMX freewheel and works beautifully! Luigi was the first one to try it out, and voila! Cardboard origami.
7Feb/114 comments
Bicycle gear scoring tool!
This is beautiful! Do you have a DIY on making one?
Hi Keith! Good question: this is brand spanking new, it just came together yesterday afternoon, and I think there are a couple of improvements to be made. Mostly the handle needs to be round instead of flat, but I will work with Nicole to make a quick instructable… We want to make a couple more, so I’ll document the steps and post it.
As requested, Keith, Nicole and Ryoko made an instructable on Make Projects. You can find it here:
makeprojects.com/Project/Bicycle-gear-scoring-tool/587/1
This is a great adaptation of a bicycle part.