Female Banana Jack Plug

thingiverse

The shaft is made from 6 millimeter thick steel and has a specific design. It passes through the case with a diameter of 10 millimeters, featuring a flat surface on its outer edge. Inside the shaft, there's a hole that measures 7.8 millimeters in diameter and 8.7 millimeters tall. This hole is intended for a press-in bushing. A revised version of this design, referred to as Rev2, has a reduced height compared to the original.