UPDATE:
10-19-2018 - I have included two new versions for the bird feeder. I found that the original version only worked for small grain seed, these new versions have gravity feed bowls that allow the seed to drop down as it is consumed. I also added a place for larger birds to perch as the original design was only suitable for passerines.

You can print the top part with the threads up and supports on the top bowl.

I think I may work on another version of this feeder with open bowls that the birds perch on, the seed comes out just fine but I don't think the birds even know it's there. It may be a good idea to fill the top part with seed as well so they know that there is food in the feeder.

I print the bottom part with threads up with no supports. The design worked well for my printer and no supports makes it a much better print. I would monitor it closely until it finishes the first platform to make sure the bridge will work without supports. If it does you're good to go.

I have included a separate bottom that you can print if you want to use a 1/2" / 12.7 mm post instead of having to hang it from a specific size ring. This was designed to replace a hummingbird feeder with a wide window mount, if you have something like that you may not need the post version.

I have a short video on this project if you're interested in seeing it greater detail:
https://youtu.be/-AUDgHKQOEo

Keep your amps up and your filament dry!