This feeder is based on the one posted by PedroKV. I feed with a small seed and found that the birds were throwing too much seed on the ground, so I changed it in several ways by re-modeling it in Solidworks. In my new design I decreased the size of the openings where the seed enters the tray and increased the diameter of the tray. Also, I redesigned the thread to match a 38-400 size 38-400 guide 38-400 doc1.

I used a 1 quart Kroger milk bottle ; many other PET bottle also have the 38-400 neck.

Included on plate 2 in the .3MF file is a cap designed specifically for the Kroker milk bottle. It may work on other 1 quart bottles as well; alternately the original hook from PedroKV is included on plate 3 of the .3MF. I used and recommend SCIGRIP 16 plastic adhesive for gluing cap or hook to PET bottles (and for all FDM plastic projects).

For outdoor use and UV resistance I printed in ASA with Polyfaire Sparkle Purple.