I work at a hotel with 150+ rooms and each room has 2 curtain rails. One of them is for the black-out curtains and has a very specific shape. The stoppers purpose is to stop the curtain sliders from falling out the end of the rail.

The original pieces are around 25+ years old and have been lost, broken, and damaged throughout time and finding replacements parts has become very difficult due to the rail shape. I modeled and printed this design to help them out and decided to share it here if it might help somebody out.

This design took me a couple iterations and is best if printed sideways so layer lines go perpendicular to the piece that the screw goes into since I had a previous failure in a previous iteration.

If anybody uses this in the real world let me know since I am curious myself.

P.S. Sorry for the poor quality print in the picture. I had an issue with my z-offset but still wanted to test the print out on the rail. I later fixed the issue all good now.