I bought this cake decorating set for my girlfriend for Valentine's Day. While it does come with a case for the tips, it is set up in such a way that two tips go into each divided section. When you turn the case upside down, or even tilt it slightly, the tips go every which way.
To fix this, I thought maybe putting each tip into it's own section would solve the issue, and it did. This led to another problem, though. We couldn't get our fingers down into the sections to grab hold of the tips. Well, that wasn't going to work.
I had added cones for the tip to sit on in the original design, and I noticed that the tips weren't really going anywhere anyway. I cut the walls down and sure enough, the tips stayed put, even when the case was turned upside down.
I've included all three designs here - full dividers, half height dividers and no dividers. For the intended purpose - holding the piping tips, I suggest either the _lowdivider or the _nodivider version. If you need a storage case for other small objects, you could modify the _talldivider model to eliminate the cones.
For the hinge, I used a coat hanger that I straightened out and slid through the holes. The one I used is a snug fit and it stays put while allowing the lid to move freely, but I found another coat hanger that was a little more loose and was liable to slip out more easily. You may want to print the hinge_test file first to see the size wire you'll need.