Allows clear view of the birds and easy fluid change. Made the ergonomics similar to the commercial feeders our birds like best. Feeding ring unsnaps from mount, quickly removed for cleaning, and is split into sections for easier cleaning and printing. Sections join together with Orings. Height of fluid in ring can be adjusted by adding washers to threaded rod supporting the bottle.

Bottle from Amazon, valve from Aliexpress (txt file with links).  1/2" threaded rod and nuts from Home Depot or wherever. Requires mounting from below. Must be installed level, I built a mount that included leveling screws. 3 or 4 1/4" bolts threaded into 4x4x1/4" flat plate. Center section attached to mount with a single 1/4" bolt.

Mounting from below exacerbated ant problem, solved with ant moat on the mounting post. The center portion needs to be strong enough to support the weight of a full bottle, I carved it from MDF, vector file included. Could easily be made with sabre saw etc. PETG probably best for all the plastic parts.

Had two of these feeders out for a full season, no issues. Perhaps 70 birds at peak, was changing both bottles about daily! Easily cut my wife's workload in half.  :)

Planning to make a new version for this season with a one-piece feeding ring of somewhat triangular cross section, so if you're interested in that check back in a couple months.