Adjustable spool holder for the Original Prusa i3 MK2

This is another Prusa i3 MK2 low profile spool holder with manual spool width adjustment using a knob.
Main parts are printed in PLA, the rolls in flexible filament, the cogwheel and the rack in Taulman Bridge (nylon).
You need more:
- 2 pieces of 8mm aluminium pipes (or rods), 160mm long each from your local hardware store or from here:
https://www.amazon.co.uk/Round-Tube-8mm-1mm-Aluminium/dp/B005DR2GUM
- 4 bearings like this:
http://e3d-online.com/608ZZ?search=608ZZ%20Bearings%20-%208%20