After seeing some of the available designs for quick-change "flipper" TP holders, I thought it would be a good engineering exercise to rework the concept with restrictions. So, this model accomplishes the same action as dragonator's "Quick Change Toilet Paper Holder (thing:123068) with the following optimizations:

1 printed part per degree of freedom
No fasteners
No support required
Toolless assembly

It still has some issues, but the idea is that it can be printed and used directly (with light assembly). No tapping, no gluing, no fasteners or tools needed. All constraint is accomplished via mutually exclusive DOFs - the flippers can only ride in the installation/removal tracks if they're in a position where normal use would not apply the force necessary to remove them, and they lock in via a cammed profile when in normal operation.

If you want to mash up the design, the final release will have STPs. The material-saving knockouts are free real estate for custom designs, I picked fractal right triangles because they ensure zero bridging without too much effort.

This is an alpha, and currently has issues!

1. Printers don't like the overhang or feature size on the flipper's dowels. I plan to replace these with ribbing or another overhang-less shape.
2. There is no return action on the flippers - they probably need some kind of spring or weight to help them fall back into place
3. The flippers are absolutely the wrong shape, owing to a constraint from an earlier frame design. Updates will improve the profile to remove the knife-edges and stuff.