Yet another spool holder, but this one is extendible to fit up to 100mm wide reels.This has been designed to replace the standard Orca 0.4x spool holder, although could be mounted on any pair of 1" pitch M4 fasteners. No support required.

http://www.gyrobot.co.uk
http://www.facebook.com/gyrobotuk

Print the two files and the extension should slot over the mount with some satisfying clicky ratchet sound (hopefully).