Ender 3 (V2) quick-switch Filament Roller Guide

I enjoyed the roller guides from https://www.thingiverse.com/thing:3052488, but I found it annoying that you need to thread the filament through the roller, and can't add/change the roller with filament already installed.

So this is a version that allows you to add/remove the filament to the roller, even if it's already fed into the machine (or even if it's currently printing). The filament can be added easily like this, but is still being held carefully on the roller (I found that the filament could sometimes come off of open rollers during retraction etc).

There is a version that allows filament to go UP, and a version that allows filament to go DOWN (I use both configurations on my printer).

Also, I added an (ignorable) expansion spot, because I wanted to be able to add a stop for my filament cleaner. You can see in the pictures that my down roller has an "arm" attached (with an M3 nut and a short M3 bolt). This arm stops the filament cleaner from climbing all the way up to