More on the wiki : http://reprap.org/wiki/X-carriage-struder
That's my vertical x-axis idea of a compact extruder integrated into the x-carriage, thanks to direct drive and linear bearings.
It was designed for the "classic" Sells Mendel, as a sort of upgrade, but it's also compatible with the Prusa Mendel (same spacing between z-rods).
The carriage-extruder is compatible with most of the existing hotends, or just ask for a diameter if your thermal break part (ptfe/peek) don't fit my 13mm.
[08/11] Replacing the old x-axis on my Sells Mendel by the VertX 0.7.3 (and major update of the wiki page)
[10/11] First print ! :D www.youtube.com/watch?v=6sF87FcMKyI
[13/11] x-carriage have mounting points now to accept more hotends
[30/11] V0.8 (x-carriage v12, x-end-idler-v9, x-end-motor-v8)
2 perimeters for the x-ends will avoid small-segments-filling that can shake the bot.
"infill in direction of bridge" (in Carve) in case it's unchecked, that will make better closing for the bearings part.
1 perimeter for the x-carriage
For the mendel-parts v6, the hole to mount the PEEK is 13mm, 18mm for the v9.
See the wiki page for assembly instructions.