This is a change for the Tumaker Voladora V2. It charge the filament from inside down. With this mod i feed the machine from the top, using my carbon tube holder design.
I have used about 40cms of PTFE tube (http://e3d-online.com/RepRap-Spares-Mechanical/Bowden/PTFE-Tubing-3mm) and 2 Bowden couplings (http://e3d-online.com/RepRap-Spares-Mechanical/Bowden/Bowden-Couplings). I recommend some double side tape to avoid vibrations.
Hope you like.