I needed a dry box that would hold two large spools (1 kg). I found a roller base (http://www.thingiverse.com/thing:104983) that I liked however I found that it was for narrow spools so I made one using the same rollers but wider for the wider spools. I made two of the larger ones then hot glued them to the bottom of a plastic box that had a good seal (see photos). Next was to get the filament out of the box and again I found a good design (http://www.thingiverse.com/thing:318580) but had to make a change to the top cap to have a tight fit on the 6mm tube that the FlashForge Creator Pro uses. So you so you don't have to go running all over the place I will provide all the parts that I used. I made two large rollers and one small one from the original design. The bearings, rod and shaft collars I ordered from the large online retailer Am*$on (Amazon), because I am lazy. The box I got from Target.

Update: If you have a narrow spool (I have one), use the small roller (Thing:104983) and then use the adapter plate that will sit on top of my larger rollers and hold the smaller one (see photo). I have also included (Thing:104983) but with the holes increased to handle the 8mm shaft.

You need:

(1) The roller SLT above
(2) 30 Bearings 608ZZ 8x22x7 pre-greased
(3) 8mm shaft 30" (enough for two large and one small roller bases).
(4) 8 8mm ID Shaft Collars
(5) Two inside parts for the filament caps http://www.thingiverse.com/thing:318580 and the top cap with my mod. I have included the lower part of 318580 so you don't have to go looking around
(6) If you want one for small rolls http://www.thingiverse.com/thing:104983 (Or use the one listed above that has been modified to take the 8mm shaft.
(7) a desiccant box of your choice (I have included one above)
(8) a plastic box that seals well (see photo of what I used)