This guy lets a regular M4 nut become a wing nut / butterfly nut for various applications. Simply push the metal M4 nut into the side slot. Should fit tightly.

Prints with no supports. The output shown in the featured image is at 0.10 mm PLA with 3 perimeters and 100% concentric infill but 0.20 mm with at least 3 perimeters and 15% infill should do in order not to break anything when tightening.

Fun fact: This design is not related to Disney in any kind =D