PrintrBot SImple Metal Spool Holder

The original 100mm Spool Holder by Lentic was one of the first things that I printed for my Printrbot and it served me well. Unfortunately, the plastic on plastic squeaking of the reels on the spool holder made me crazy. I added a roller with bearings and a tray to support it. I found that when I just mounted the roller directly, it was placing too much strain on the mount and it would quickly sag, so this provides the required extra support.