Extension for split filament spool

This is an extension for the threaded filament spool. I wanted to be able to wind more filament, and the spool is already about as wide as my printer can go. So I made it longer instead. This extension adds about 5cm, which was about perfect for my Filawinder.

Thanks to the original author for uploading the CAD files! In the same spirit, I included the 123D file for the extension.