I use external Box to keep my filament dry but fast retraction causes wear and tear on the end of the bowden that contacts with the metal ring on the Bondech extruder. I decided to make a tube guide to protect the bowden tube which lessen the ticking/knocking sound that sometimes cause under extrusion or failed prints.

Pushing the filament on the tube works just fine when loading the filament. May be a bit cumbersome but well worth it as it protect the tube and lessen fail prints (only those cause by deformed tube). Removing the bowden tube from the guide and loading filament how you normally would push it work well also and during loading of filament the tube will guide itself inside without assistance.

Note:
- Printed in CPE+ and it fits just fine, little to no play but not friction fit on the extruder body but it sits well in place.
- No need to remove the metal ring on the extruder body.

EDIT:

Re-uploaded new model.
- Reduced the ID of the filament guide to reduce the play that bends the filament during fast retract.