I have a Makerbot Mini, and OK, the small spools.... and plenty of 2Kg PLA options on large ones. So here is my simple/stupid adapter that lets you use a Mini on any spool.Print out the adapter with the slot facing up for no need for supports. Mine was on the Mini at 25% infill. The STL file is in inches. You'll need 31.75 cm of 3.8mm Teflon tubing (.150 inch). I used two thin 1/2" velour pads from a Dollar Store pack on one side of the slot. This is enough to provide a nice friction to keep the adapter in place. The spool is set behind the Mini on any number of options for spool holders, like this one: http://www.thingiverse.com/thing:169080 My setup uses two mini T-slot rails and some M8 rod and bearings.