Fruit Fly Trap Bottle Cap for PET 28 1881 Bottles

Turn an empty PET bottle into a simple reusable fruit fly trap.

This fruit fly trap bottle cap is designed for PET 28 / 1881 bottle threads, which are commonly found on many soda and soft drink bottles. The model prints as one single piece and screws directly onto a compatible bottle.

The conical entrance helps fruit flies get inside, while the grippy outer shape makes the cap easy to screw on and off. It is mainly intended for fruit flies, but it may also catch other small annoying insects.

Printing is simple:

- No supports needed
- No brim needed
- No raft needed

Recommended settings:

- 0.4 mm nozzle
- 0.16 mm layer height recommended
- 0.20 mm or more may also work, depending on your setup

Tested materials:

- PLA Basic: good for indoor use
- PETG HF: good for indoor use and better suited for outdoor use

Measured print data:

- PLA Basic: about 45 minutes, about 12.3 g filament
- PETG HF: about 61 minutes, about 12.15 g filament

Recommended bait recipe:

- 2 tbsp or 2 parts juice
- 1 tbsp or 1 part apple cider vinegar
- 1 to 2 tbsp or 1 to 2 parts water
- 1 drop of dish soap

Just pour the mixture into a compatible bottle, screw on the cap, and place it near the problem area.

Notes:

- Designed for PET 28 / 1881 bottle threads
- Fits many common soda bottles, but slight differences between manufacturers are possible
- Other filaments may also work, but they have not been tested yet

Bottles and brand names shown in the photos are only examples of use and are not part of the model