This is a two part fishing bobber cap for your Stanley or other tumbler or cup. The part that covers the straw and is designed to be printed in flexible TPU (use the “StrawCapV3.3mf” file or print it directly from MakerWorld here: https://makerworld.com/en/models/488111#profileId-400979).

The bobber is designed to be printed in PLA or PETG with a 0.2mm nozzle, though I've also included a profile for a 0.4 mm nozzle. The profiles are made for use with an AMS, but since it's only 2 filament changes it can easily be printed without an AMS by simply changing the filament changes to pauses, and manually swapping filament. Once both pieces are printed, simply glue them together, and you've got yourself a fun and functional straw cap! I used Gorilla Clear Grip, but any glue that adheres to both PLA and TPU should work.

Check out my profile for other cap designs that fit the same TPU insert.