Here is an update to the pre-charge knob. I made it stronger and adjusted the orientation to be straight.
I recommend using a 10 ohm resistor or less with it.
Here are the files:
Pre-Charge Knob - Knob.stl (1.9 MB)
Pre-Charge Knob - Shell.stl (391.5 KB)
Pre-Charge Knob - Hub.stl (295.5 KB)
Also a link to the resistor I am using now:
http://d.digikey.com/R00N0o9XR71000k0SfKaHpH