Prusa I3 spring loaded idler extruder

this is a derivative of Prusa I3 Extruder PG35l stepper with 24mm mount spacing (http://www.thingiverse.com/thing:81140).

The reason I made a derivative, is that the filament guide hole I was uncertain having it clamped between the idler and the main extruder body would work correctly, as I don't have my printer built to make these to try.
The 3d model of the springs I just got of a spring company so its up to you what springs to use, but for future reference if you have any issues with getting 3d models of springs go to (www.assocspring.co.uk) you can download the models of there products

ps the holes in the groovemount to fix the
This will fit a jhead with the the tophat of the jhead measuring in depth 5mm with the groove mount fixture also the fan duct attaches to the groove mount, my groove mount will be made from aluminium
i have put this under work in progress OUTDATED**i designed the hole for the hotend for rev 1 e3d and the change the hole spacing my advise is go into freecad open the freecad file and go into the tree a and change the hole parameters