Recorder v3 updated 2021-07-27

Be sure to check out my improved design that features a low B-flat hole: https://www.thingiverse.com/thing:4572413

Version 3.7 fixes a flaw in earlier versions that affected the alto model and caused holes below the middle of the instrument to not affect the sound. If you've printed version 3.5 or 3.6 you can print just the "seg2" STL as that's the only part that was modified, and sand it down to fit your other segments.

When printing any STL from this Thing, be sure to get the joints correct, or the instrument won't play! If the joints fit together easily, i.e. without a LOT of effort, then they're too loose and the instrument won't play. If that happens you should increase your horizontal expansion. Don't forget petroleum jelly in the joints to help create a tight seal. The other critical thing is porosity, especially around the fipple. You can test your printer and filament with the "whistle only" STL; ensure the whistle makes sound, and that the edge has a smooth solid straight appearance.

The tolerances on all of the joints is 0.2mm. You may have to apply a horizontal expansion in your slicer settings to print this correctly on your printer. I recommend printing ahead of time a tolerance tester such as this one: https://www.thingiverse.com/thing:4552242 simply find the number for a tight fit, and if it's less than 0.2mm then set your horizontal expansion to the difference. You will still have to sand the joints as that is the best way to get the perfect fit.

Based on cymon's recorder that plays well except for the very lowest notes. I made the bore larger to accommodate more airflow to get better volume at the bottom of the range.

I also adjusted the placement of the holes. Recorders are notorious for having some notes off key and I wanted to remedy this. (True you can adjust airflow to tune each note but this way it's more consistent and less to remember.)

Video demonstration of the soprano recorder: https://youtu.be/QQ1ixOZWio0 and the alto (recorded on 2021 Feb 3): https://youtu.be/e5yc2Gg7KVE

For version 3.4 I've included separate soprano and alto STLs. If you scale the soprano up to alto size (150%) the size of the fipple will require a lot of air and it will literally take your breath away, however the remaining parts will work fine. I will likely at some point design a tenor (200%) version however that is a >2 day print. In theory the alto STL scaled up to 133% should produce a tenor recorder, however the fipple might have to be further narrowed and the finger holes may have to be made easier to reach.