I printed the fantastic Universal stand-alone filament spool holder from Creative tools (http://www.thingiverse.com/thing:508896) and have been so happy with it - it's brilliantly designed, looks great and has does everything you can ask from the filament management system all in one! My only issue was that the Printrbot Simple Metal likes the filament to come from above & behind the print head, and the spot I've chosen for the spool holder to live is too low, and off to one side.I wanted to stick with the great design, and make it perfect for my Printrbot, so I mashed up this design. The idea is that the spool holder can live pretty much anywhere now, and I feed the filament at the rear of the machine, up through a hoop on the rear Z-axis rod and into the new design part mounted on the front Z-axis rod which guides, cleans and lubricates the filament before putting it into just the right spot for the print head.I added a 2mm PTFE tube in the front of my guide, which means that the filament glides through and doesn't grab or grind on the front of the guide, which it will do when the filament is pulled at a sharp angle.Thanks again for the great tool overall Creative Tools - I hope my mash-up here will encourage others to try the management system.www.soldersuckerblog.com/home/random-ramblings/filamentguideforprintrbotsimplemetal