You want to connect a filament spool to your Prusa Mendel? The filament spool will balance on two treaded rods.This mount is a bit shaky, but so far durable. Too much load might cause damage. So use it at your own risk.Update: The lower structure is not stable enough. At 37°C room temperature and a weight of 2 kg the arms bended. The spool mount broke. Please upgrade to the new fortified spool mount. http://www.thingiverse.com/thing:29142 Or use far less weight.I build it this way: Print 1 x "M8 spool mount v1.stl" + 2 x "M8 top sm v1.stl"Connect those parts with two 18 mm M8 threaded rods. (The pictures show longer rods.) Connect the center part to a z-axis motor mount end. Use a 15 mm M8 threaded rod and a spool bearing system to connect your filament spool.The spool bearing system I am using is: Parametric Spool Bearing (made of washers) http://www.thingiverse.com/thing:23701