This is a 100mm centre for the spool that Diamond Age Solutions supply their 500m spools of 3mm and 1.8mm PLA, and 1.75mm ABS on. Each centre takes a 608 bearing, and a piece of M8 rod goes through the middle. A set of locknuts on each side keeps the centres in place.

The file is parametric so you can change diameters to suit.

Print out and press-fit a 608 bearing into the central depression. Make 2. Stick in spool.

If you need a ground-based support stand, try this one: http://www.thingiverse.com/thing:6202