SummaryI do love Kliment/Josef's compact extruder and I have made some variations myself that work pretty well. However, I was a bit disappointed of the small useful area I was getting from my Mini i3 due to the big size of compact extruder. This is a small direct-drive extrude for j-head hotends. Please note it is not a good choice if you want to use it at any speed above 40mm/s with 3mm filament. It can do 100m/s for 1.75mm filament. Now I can get 120x120mm out of my Mini i3, though it has become a slower printer. Perhaps with 1.75mm I will get it up to speed. I am not sure the 625 bearing for the motor shaft is needed but it seems to cause no harm. Lever and spring support, in orange in the pictures, come from http://www.thingiverse.com/thing:43411InstructionsYou will need: 2 M3x20mm 2 M3x18mm 2 M3x30mm 1 10mm diameter spring, 30mm long (mine came from a soap pump) 1 625zz bearing (maybe you can do without) 1 8mm drive gear 1 608ZZ bearing You can likely stop the print once the part is 35 or 40 mm tall (no need to print all the way up the motor support).