Summary

My daughter's 5th grade class has a "junk band" project so we decided to design a 3D printed violin. It's a toy, but actually plays a little.

Instructions

UPDATE: Added pegV2.stl with a wider knob for more leverage.

Print all pieces raft-less with the flat sides down. I used ABS at 15% fill.
Clean up the neck joint on the body with sand paper. There may be some dropped loops that need to be removed.
Glue the neck and nut together. I used 5 minute epoxy.
Glue the neck to the body.
Fit the bridge to the body with a light sanding to the inside edges of the feet until they both fit snugly into the holes. Don't use glue here.
After the glue has cured, use a guitar D/G string or suitable violin string. I tried an A or E string and it wouldn't work very well. A wound D string probably works best. If the peg slips, remove it and spred a little superglue inside the holes and on the peg. Wait until the glue dries before putting the peg back in.
Use a smooth ribbon and tie it through the holes in the bow. See picture for an idea. Compress the bow and tie off the ribbon so there is tension.
Coat the ribbon and string with rosin.
Enjoy scaring the cat!