It's an horizontal mini-spool, to store a small amount of filament right under your Huxley.
I wanted to put the spool under the Huxley to go further in my "carry-plug'n print" need of a portable reprap for short demo in street, conference, etc.
It appear smaller that I thought (thus the "mini spool"), but it works and can load 50-60m of 1,75mm filament.
As on the picture, its a square of M8 threaded rods (directly screwed in the printed parts) which the Huxley is put on (I used some leftover from a Mendel build, previously used in another spool, approx. 2* ~240cm and 2* ~150cm)
Set the distance with the spindle
Now that you have a splendid mini-spool built, just put the Huxley on it :)
(you can secure the huxley on the feet with m3 bolt or zip-tie)
Optional filament guide
In case you added a heatsink on the extruder's motor, it can help
Proof of working :p