This standard-size filament spool is fully printable on most 3D printers. An optional extension is provided, allowing more filament to be wound onto the spool. See the video and tools at http://www.thingiverse.com/thing:352657 for information on how to quickly wind your filament onto this spool.

2016-12-11 V2 spool parts update now includes a new (125mm x 125mm x 70mm) spool design with an optional extension for extra capacity and a spindle that will allow the use of a 14mm high printable bearing (like my "airless tire" thing 917335 or the easy-to-print V2_cylinder_bearing, included here and recommended) to help the spool rotate smoothly. Or, if you prefer, customize your own bearing instead using http://www.thingiverse.com/apps/customizer/run?thing_id=251872. Set it to have an inner diameter of 13.5mm and a height of no more than 14mm. (Avoid the "concave" option, which didn't work well in my tests.)

Please note: the V2 threads on the spool and extension are not compatible with the previously released spool, which has been removed to reduce confusion. Two versions of the spindle are provided. The horizontal one (which includes two tear-off "helper disks" to help adhere it to the print bed) is stronger but lacks the "spindle stand" base on the vertical spindle model. I recommend the latter.

The spindle bearing also works well with other small filament rolls, such as Taulman T-Glase.