This is the long promised Return Chute for my Marble Lifter https://www.thingiverse.com/thing:2563160. You need to make that model first, then attach this to it with Krazy Glue as shown in the pictures. It takes a bit of careful adjustment to get the transition points right. Be patient.

See the video at https://youtu.be/7xuPRJ_2Jgw