MP Select Mini Extruder Knob

I found it a little annoying that I couldn't visually tell if filament was being sucked into the extruder, so I made this little knob. It really serves two functions: as an indicator that the extruder is sucking, and as a way to manually feed filament in or out. Mostly, I just like being able to see that the extruder is running.

It's a pretty tight fit, and I made it that way on purpose. It shouldn't require any glue. I simply shoved the part onto the extruder motor shaft as far as I could by hand, and then tapped it the rest of the way with a heavy object. If it ever needs to be removed, I'm sure pliers would do the trick.