I recommend to print it with a wall thickness of 2mm and to use wood pla. Because you'll want to sand it and glue the different parts. Also, you'll want to varnish it.
You'll must tune it with bee wax!
It's left handed.. (Long tube on the left).
You may use a mirroir reflexion to make it right handed.
C8-C9 must be printed with a 0.4mm noozle at max to print. Lower would even be better.
C7-C8 Should be printed with a 0.4mm noozle too.
C6-B6 should be printed with a 0.4mm too
C5-B5 may be printed with a 0.5mm
C4-B4 should be printed with a 0.5mm (or 0.8mm if you dare to do a lot of sanding and your scared of failed print.)
C3-B3 and C2-B2 must be printed with at lest a 1mm noozle, otherwise it'll take years.
Reinforcement and tips “Embout in french” can be printed with a 0.5mm
This model has originally been though to be two different models but one could easily build a flute of any range within the C2-C9 range.
Here is the proper link to the Tenor version.
https://www.printables.com/model/139274-chromatic-pan-flute-4-octave-tunable
Here is the proper link to the bass version.
https://www.printables.com/model/327823-chromatic-double-bass-pan-flute-4-octave-tunable
If you wanna see it in action: :)
https://drive.google.com/file/d/1kG9_Im1Ty0s8Dnik2LYsHAQSjDir9KjF/view?usp=share_link
Note*******
This as not orginaly been made by me. It as been made by Caran.
The original file or here :https://www.thingiverse.com/thing:1129462
The original had a major issue. The tubes where calculates to be exactly on the right note. But for the high ones they were too high and one cannot tune it down. So I have corrected the model by adding it 2 cm on all the tubes.
I also added a little octave for fun and some reinforcement.
Then I got serious and added two bass octave.
The author remixed this model.