Printrbot UBIS 13 hotend (though any groove mount will probably work) Printrbot Gear Head Extruder Gears & Bearings (it seems they may have stopped selling these alone... which would suck for this design. Will ask Printrbot.) Ultibots PG35L Motor + Heatsink 6x - DeltaPrintr Magnetic Balls 6x - 10mm M3 Screws 2x - 16mm M3 Screws 2x - #4 Thread Rolling Screws (design ought to be modified to use nut-traps and M3's here, in retrospect...)