You will need:

• 4 x 608 roller bearings, washers optional-(1)
• 24 x M8 nuts and washers-(2)
• 2 x threaded rods, M8 x 13in/330mm
• 4 x threaded rods,  M8 x 8in/200mm

So, how about those Colorfabb 2.2kg spools, eh? Kinda massive, huh? Not too easy to fit onto the side of your printer, ya dig? Almost comically large, y'feel me?  Anyway, this is a rolling cradle for Colorfabb's Hugh Mungus-approved filament spools. We were going to use some 80/20 steel for a frame, but space was an issue and we had these threaded rods left over from a 3D scanner we never got around to building.  

1. The bearings in mine spin pretty freely, but that's because I assembled the rods to be fairly loose. If you'd like something that feels a little more solid, go ahead and add washers to each side of the bearings. However, I'm going to advise you to either sand down the pegs or scale them accordingly for the sake of the spool's width. 

2. Since I was asked about the logistics of creating our own plastic hardware by my higher-ups, I used the chance to make my own spacing washers. I've included them here for you nutty types who want as many parts 3D printed as possible, but I'm not going to tell you they're essential to the design because they're not.