Summary

Update:
This was the first thing I designed and tried to make work.
I had 3 versions of this and only published the first. my bad.
I had also tried using PLA for this instead of ABS. The original flat pocket
was a rubber mixture of some kind and didn't work well over the long haul.
I've just uploaded the version 3 of this... Feel free to tinker with it.
In the end a sheet of plywood and some bolts did the job..
Maybe ABS will do better.

This is my first attempt at designing with Tinkercad.
This part is a replacement part (hopefully) for the Beddinge futon.
My son broke several of these on his. The originals appear to be made from a low
density polyethelene or polypropeline plastic. The ends tend to bust out or break
the mounting tips off. I will try to print this with PLA first.

This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/jMsz3PsqTgF