"Frictionless" PLA spool holder for overhanging mod

I work in an environment where I can't babysit the 3D printers all the time. After fully upgrading our Replicator 2 with the extruder upgrades, glass build plate, and overhanging filament spool holder, I thought everything would be great, but we were still losing prints.

The epiphany came when I was watching the printer in action and realized that the 3/8" threaded rod we were using as the support is -- get this -- threaded!! I watched as the filament slowly made its way to the extreme right of the holder, and then when the extruder head zipped back to the front left of the build plate, the sudden tension ripped the filament right out of the extruder.

So, I devised this little upgrade.