Update: There is a newer version of this that is big enough to deal with the width of a Printrbot spool and the diameter of a Makerbot spool here: http://www.thingiverse.com/thing:368850
I received a Printrbot metal last week and wanted a spool holder for it but I didn't want something that was going to sit next to it and I didn't want to print half of it and then go out buy the rest!
I found mytanoojj's Filament guide for Printrbot metal (see remixed from) and quite liked this and so this design is designed over it.
Sorry about the dodgy photos, I printed it in black and the bot was busy while I was taking them.
I printed this at 0.3mm layer height to save time.
I printed it on a Rep 2 but it can be printed on a Printrbot metal.
No support is required for this print.