CAPSTAND is my solution to an annoying problem. I keep my toothpaste tubes on a shelf, standing on end, but the screw-on caps are so small, the tubes are easily knocked over. Some toothpastes have larger caps, which makes those tubes more stable, and that's what I wanted to create, but the caps on my two regular toothpastes are slightly different sizes. So instead of making two different CAPSTANDs, I designed one which will fit a variety of small cap sizes.
This prints in two pieces. The main section is a cylinder containing a unique wide, tapered, flat spring, which can adjust slightly to fit different caps. It was printed separately so the spring component would be free to flex; print with the end where the spring is flush to the cylinder, on the build plate. No support material required. Then the end cap snaps tightly into place on end where the spring is recessed. The pieces were printed in PLA, and there's enough flex to fit both of my tube cap sizes.
To use, first loosen the toothpaste tube end cap a little, and press the CAPSTAND over the cap, using the spring action to grip the cap. Now tighten the cap back down, but only as much as the CAPSTAND and cap can then be unscrewed without the cap slipping; might take a little trial-and error. Once set just right, your toothpaste tubes will stand easily. Enjoy! Steve