Even though I've built this one from scratch I declare this as a remix because I got the idea from
which I made and was quite happy with. My wife and daughter saw it differently and pointed out some things they didn't like ... so I had to make a special one for them. Girls!! ;^)
What I did:
First thing was to make the base a little larger, so it would give more room for the "input"-slot. Then I made the gap in the base wider, so you can insert even thicker tubes. The second thing was to create a key with a slot that is open at one side, so you can remove the empty tube more easily.
Depending on your printer and your settings it is possible that you have to sand the open end of the key a little so that the rachet fits onto it.
Hope you like it like my girls do ;)
Update 2019-02-21: I've added modified files for the key and the ratchet. The key now has tabs so the ratchet wheel goes on and off the key a little easier. I had to put a little "thingy" on the bottom-side of the key so it would be a little higher on the printing-plate. This was the only way for me to print it with a working support (tree-mode) and get a useful result. If this is necessary may vary depending on your printer and your experience. I'd be greatful if you would let me know which version works best for you.