Summary

Full scale mandolin, based off dimensions of a wooden instrument.
https://youtu.be/VRPSE-dukQE

Before you spend 40 hours printing this, please note:

1. Mandolin strings are tensioned over 5kg each. With 8 strings, that means over 40kg (88 pounds) of tension trying day and night to implode the device. I make no guarantee that this device will not implode in your hands, causing potentially severe harm. You assume this risk if you choose to proceed. How you print it will greatly affect its strength.
2. This is not a beginner project. You must have a good command of your printer and be able to get high quality results even with significant overhangs.
3. The joints are tight by design, and will require smoothing with a rasp and sandpaper to assemble.
4. I have no idea how well it plays. I'm not a mandolinist. As above, I can't even say for sure it won't implode. Soon as I get it strung, I'll try to post a video with sound. If I survive the stringing process.
5. Neopolitan mandolins typically have a single hole, instead of 2 F holes. I just like the look better this way.
6. Final verdict (8/18 update): PLA is not the right plastic to use. Tuning the strings causes the neck to bend toward the soundboard, and leads to a sizable gap between the strings and the frets. This might not be a problem with a more rigid plastic.

You will need:

• A large volume printer, 300mm X 300mm or larger (CR-10, Tevo Tornado). Any attempt to slice this up for smaller printers would require splitting the bowl, which is just... ew. Nasty.
• About 750gm of plastic
• Tuning machines: http://a.co/2qpEzXG
• Mandolin strings, loop end type
• Glue, E6000 or cyanoacrylate
• Around 30 hours of printing time for just the bowl.

Tips:

• Print in current orientation.
• Use supports where they touch baseplate, only.
• Print the bowl with 0.2mm layers. This will allow you to cut out the F holes and fretboard peg hole in the bowl.
• Print it strong. I used 4 walls.