Originated on Printables.

I remixed Tristan's model to be a little more robust, as well as extending both the length of the slant, and the overall length. This placed the chain always on the bracket. The slant is for any drag remaining.

Printed using Creality PETG Black @ 30mm/s with 100% infill. I used normal supports with anywhere placement to ensure the slot has the correct sizing throughout the print. Printed topside down.