I changed the ends (made the bearings totally enclosed) and published v2 here: http://www.thingiverse.com/thing:552536
Uses skateboard bearings (608 - 22mm OD, 8mm ID, 7mm thickness).
I used 5/16" wooden dowel as the shaft.
The .fcstd files are FreeCAD files (created using the linux version 0.14)
I used six #4-40 x 3/8" flat head screws to hold it together, although I imagine that M2.5 x10mm shoud work as well.
Print 2 end pieces, 1 base, and 2 solder spool adapters.
Use 2 skateboard bearings and a 5/16" wooden dowel for a shaft.