This is a simple spool holder for filament spools of up to 200mm in diameter, designed to snap on the to the top rods. The rods should be spaced 58mm apart like on mine prusa i2. The single STL file includes both sides of the spool holder and only needs a built area of 170 x 140mm 15 dec 2013 incorporated slots for the spool holder rod instead of holes reinforced the spool holder around the bend Just print both sides of the spool holder at once from the stl file and use an 8mm smooth rod to hold the filament spool in place