I cloned the poop chute as a starting point for making a motorized version.

The original version has the following problems:

1. It will always have waste stuck at some point regardless of any attachment that claims to solve the problem.
2. The chute is placed at the rear of the machine, which is obviously bad for a desktop machine
3. All of the attempts to solve problem 2, e.g. waste bin with a slide, only worsen problem 1.

To solve all of the above problems at once, it is necessary to motorize the chute. To be specific, the paddle needs to sweep actively instead of passively.

Anyways, here is the model for the original chute, with minor modification for 3D printing with minimal support.

Please paint the green region to enforce support.

Feel free to edit the part, e.g. add screw holes for waste toilet.