3D Printer Harp strings (Musical strings light, maybe rubber bands? piezo sensors?) Ball strings (Thread, fish line) Glue - to attach base and top after printing Door mounting - (double-stick tape, screws, glue,etc) In progress - I would greatly appreciate anyone who prints one to provide any feedback about settings and sound/volume/settings that worked well for you. I know there are probably ratios that can optimize the resonance, if you know them put a comment below. I would also like to add some press in tuning pegs at some point to make keeping the harp in tune easier. I did print a small test, and see something I need to change. here is a quick glimpse of the 1st iteration. It does make noise! :-) https://youtu.be/TC4jyNVN6qc You may get better results changing some of the values of wall thickness, hole size, ball size, over all ratios of length, width, and height of the box. The 3d printed balls were done with 100% infill to make them heavy enough.