I finally got rid of my old Makerbot 2x 3D printer. For a long time I blamed the printing problems on myself, not the printer.
I ordered and assembled an Original Prusa i3 MK3S+.
Excellent manual led me through the assembly process, and it started printing right away.
So, I printed my latest prototype fret buttons (GH-BTN-LesPaul-360-V4) with a 1.5mm set-back.
They fit the guitar P E R F E C T L Y with no adjustment required. I was super-pleased.