Replacement knobs for a Nord Electro, Stage, and Piano keyboards. They should work on series 5 and 6 but I'm not sure about others. 

There are two types:

nord-knob: Regular knob with no pointer.

nord-knob-pointer: Knob with slot for pointer which is printed separately and glued on (super glue works well).

These fit perfectly when printed on my FlashForge Finder at normal 0.18mm layer height but if it's too tight or loose for you, just adjust the scale by 1% at a time until you have a good fit.