Now here is my take on an internal bee feeder for standard mason jars.

It has a thread for standard TO82 (82 mm twist-off) canning jars. This is by far the most common type of thread found on larger size mason jars (e.g. for honey, pickles, salads...) where I live (the thread is actually approx. 81 mm in diameter and has multiple short threads rather than a single long one). I use 720 mL jars but they could be pretty much any size you can fit inside your hive.

They are not as convenient as external feeders (which you attach to the outside of the hive/super - you may want to check my thing no 4485602 if that's what you are looking for) as you have to open the hive, but in my experience internal feeders just work better. My bees seem to love them.

Hope your bees like it. Here is a collection of some of my Beekeeping Designs on Thingiverse.

It should be an easy print. No supports needed. PLA or ABS. Make sure you choose a color your bees like! ;-)

Enjoy!

You may also want to try my external feeder: https://www.thingiverse.com/thing:4485602

Print Settings Printer brand: Creality

Printer: Ender 3

Rafts: Doesn't Matter

Supports: No

Resolution: 0,28

Infill: 30%

Filament_color: Any color your bees like

Filament_material: PLA or ABS