Working on a remix that adjusts some of the pitches and makes the bore larger for more volume. Initial tuning is done; I'll post my STL soon.
Each of the recorders in the picture is a separate revision.
Me playing my most recent version: https://youtu.be/QQ1ixOZWio0
Some filaments will not print airtight and therefore will not work. Additionally, if your print has any underextrusion or any blobs or other surface imperfections, that will degrade the sound quality of the instrument.
Make sure you have plenty of raft margin (I'm using 15mm) and very good bed adhesion and layer adhesion. It's easy to lose a print when the columns are almost complete and the nozzle bumps one, causing it to come undone.