I really like tamel55's Small Spool, but I needed to load a full pound of nylon onto a spool, and the small spool was too small. I used Slic3R and 3D Builder to slice off the male and female parts of the spool halves in the original thing stl files, and fused them to make a male/female spool extension.

You just print it and thread the coupler extension in between the halves, and viola', the spool is now twice as big!

Woodstock Rostock Delta Printer

No

Yes

0.2mm

15%

Print with the male side down, and use supports for bed only (in Slic3R, anyway).