I wanted to make an articulated train that could grow as long as people wanted. The problem was coming up with a joint that would be be flexible but easy to print.
I came up with this thingie and I thought I should make it available to other makers under a non-restrictive license.
It prints in place and without supports.
You don’t have to use it for trains of course. I’m making myself another version of my ducks for example. 