Summary

I ordered some new PLA from OSPWRD.com, and they came on these bigger spools, so I made some fittings to mount them with bearings on a piece of threaded rod.

I guess I have humidity problems, cause all of the laser-cut spools and coasters I have are all warped to hell, so they don't work all that well. At least I could scavenge the old ones for the bearings. :D

I also made a stand, but it's kinda junk, so I'll upload that after I rebuild it.

Instructions

You are going to need:

1 x 1/4"-20 x 12" Threaded Rod (That's what i had on hand, you could go longer I guess).
4 x 1/4"-20 Nuts
2 x 1/4" Washers
2 x 608 Bearings (I think that's the kind of bearing I had, I scavenged them off the printrbot spool coasters).

Print two of these, one for each side. I used 25% Infill, 2 Permieters and 0.2mm layer height. I print these kinda fast, so they come out kinda rough. A set of those little diamond files comes in really handy.
I place the inside hub on first, then a washer, then a nut, then the knob (you'll see an inset for the washer and the nut on the bottom. Screw it on about 2 inches in (the hub will be loose, and you want to make sure the rounded cup part is pointing in. There is picture below which shows the order of parts.
Add on a bearing, one of the sleeves (this centers the threaded rod in the bearing) and a nut.
Put your spool on, and assemble the other side the same way. Tighten the knobs so it's comfy, then tighten down the bolts holding the bearings.

NOTES

The reduction in friction is ridiculous, these things will spin with almost no effort. Plus, at $1.50 for each threaded rod, I've made a set for each spool on hand, so I can quick-change on my desktop stand.

Big Filament Spool