Quickly change 38mm filament spools using this amazing free spinning spool holder. The holder rotates freely to reduce friction and ensure smooth prints. Convenient slots enable you to quickly secure the spool using a filament clip. As a bonus, you don't lose filament clips. Long (5lb spool) and short (2.2lb spool) 38mm spool holders are available. The long version supports both 5lb and 2.2lb spools. Both 1.75mm and 3.0mm filament clips are part of this project.

Video of the spool holder in operation:

http://www.youtube.com/watch?v=KPtGQ4V8H-0
http://www.youtube.com/watch?v=Ee25BwZchII

This spool holder requires a bolt and lock nut commonly available at most hardware stores. The cost is usually less than 40 cents.