Wanted a ball shifter knob but due to the assembly and design of the original I had to add a threaded end to add the knob after the lever is inserted into the H pattern gate. 

Threads are a standard M6 and the threads in the ball were slightly enlarged for a smooth threading fit.

Printed using:

• eSUN PLA+
• 0.16mm layer heights 
• 2 wall layers
• with brims

Planning to add some other style shifter knobs. Requests are welcome!