Originally designed and shared March 20th 2012 - *Update* 21st - March - Added Greg/Wade extruder adapter plate and all the Sketchup files so you can make whatever adapter plates etc. you may need.*Added* 31st March - Belt clamp and Low profile catch together - as requested.Both parts print vertically, join them together with 20mm M3 bolts.The Linear bearings slide in and secure with a zip tieIt has a belt adjuster on one side of the belt clamps - see photosThe Extruder is based on Greg's excellent design, with a few mods and the extensions allow it to fit on the Quick-Fit X Carriage.You need two x M4 (13mm) 624 bearings for the Quick-Fit Lever.It also has a fan mount on one side.It's designed to be expandable (easily made wider) by adding spacers between the two halves - without taking off the printer. - just in-case you ever need more room to fit triple extruders !Check out my Blog post for further details - richrap.blogspot.co.uk/2012/03/mendelmax-quick-fit-x-and-quick-fit.htmlA Video of it in operation can be seen here - youtu.be/ffICsLWzn2o