One of our cats always scoops out the litter out of the robot.

Therefore I made a guard to prevent most of the litter from exiting.

As it's kind of complicated to make the fit still isn't 100% but as of this version it stays in place when the robot is turning. I will do some more long term testing and will adapt where needed.

Just to be sure, i suggest to add a modifier to the corner clips and the front board with 100% infill.

For best results, print the inside piece at a 45° angle. Support is needed for both pieces.