Cleanup and tuning Because the flute is printed upside down, there will be support material inside the tubes used to build the closed bottoms of the pipes. I first used tweezers to twist out as much material as possible, then used appropriately sized drill bits by hand to remove more support material, then finished up with appropriately sized straight end screw drivers plunged and twisted into the pipes. The cleanup took about 30 minutes. Tiny holes in the pipes can make the flute difficult to play. After cleanup and a light sanding you can coat the outside and/or inside of the flute with a primer coat. I used Vallejo acrylic-polyurethane surface primer on the outside surface of my PLA flute and and got a noticeable improvement from the smaller pipes. Traditionally small pebbles are used to tune the pipes. I found a Decorative Filler at a craft store (Michael's) in the form of small clear plastic squarish beads normally used in decorative terrariums. Those, and a music tuning app like Pano Tuner, allow a quick tuneup. The provided cap keeps the tuning beads in the pipes when the flute is idle. I used 100% infill/line pattern and printed at low resolution on a Robo 3D R1 Plus.