Note: Designed for 3mm Filament 07-03-2015 Beefed-up Fan mount and added nut traps to it. Ducted Fan add-on - Thing: 899166 12-05-2014 Added new idler that works with non Eckertech hobbed bolts. May help with 1.75mm. Included modified .scad file so you can adjust as needed. I like the Ecsktruder better than the Gregs, Wades, hinged, ..... But attaching it to the Wallace required some cutting and an extender for the smaller J-heads. So, I melded the Extender to the Ecsktruder Base. Now it's one print and the filament has less distance to travel. Note: The extender edge is slightly off the bed. The print worked for me, but your milage may vary. If soemone can help me get the plate side verticies lined-up, I'd apreciate it. UPDATE: Now with a grove for easier wire placement. Sorry, still not fixed the other problem. UPDATE 2: Moved the HotEnd mounting holes down! Now all the vents on the small J-Heads are exposed and there is more clearance below the X-Carriage. Fixed 90% of the printing problem! Also enlarged the hot-end opending. Still snug but much better. UPDATE 3: Now with recesses for the hot-end screws!Print Wallace Body and Mirrored Ideler. Print Eckstruder gear set. Assemble as per Eckstruder Prusa. Note: hot-end opening is tight! Nolonger as tight as the original Extender.