I made fidget tool to practice/strech guitar playing/fingers streching, everywhere without making noise, or carrying guitar. Frets are equal to 5 first frets of my acoustic guitar, all “strings” are basically a buttons, almost equal to string (all of them need to be pressed with almost the same force as in a real guitar, for obvious reasons, the “strings” work best when they are the width I chose, rhicker can brake to easly). You are welcome to change anything you want, I give you FreeCAD file to easy change., Only 6 frets (silver on photo) and 2 dots (I dont print them they are only estetics) in project must be glued in,

Print:

• whole parts I print in PLA, but I guess u can use also PETG;
• only springs needs 100% infill just to be stiff enough;
• springs need to be printed on the side,
• springs and strings you need 6 pcs, there is one on the fret (x5 frets) in file;