UPDATED E-stop knob, parametric-ish

This is designed to replace the standard black knob on a push-off pull-on switch.

I will be using it to control the ATX power-on line, i.e. pin 13 to ground to turn the power supply on.

It will be part of my Printbot control panel, a WIP.

I can't recall where I got the switch, but presume it was in my local car accessories shop.

These are what old cars, really old, used as headlight switches. Without relays.

Note: Technically this switch would not qualify as a safety switch, but f