Summary Do your prints have shifts? Is your filament tugging on the spool? Do you think there may be a better way? Now there is. This holder works with all types of spools with wide flanges, spools with narrow edges. The double bearings allow the narrow spools to ride in the gap between the two bearings. This helps with keeping the spool centered. One side of the holder is cut out to allow for small spools that are full of filament. Just flip the holder around to put the cutout on the inside and you are golden. On the big spools this isn't an issue. Instructions I printed these 100% fill. Parts print two holders. one for each side of the spool. 8 x 608 bearings. http://www.amazon.com/gp/product/B002BBGTK6?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00 12 x M8 flat washers 4 x M8 bolts and nuts. The bolts need to be 35mm long. Installation slide bolt into base then washer onto bolt then bearing onto bolt then washer onto bolt then bearing onto bolt then washer onto bolt then slide bolt into other side of base then attach nut to bolt I put washers on the outside of the base too, but you don't need to do that. Also, my bolts were 45mm, because that is what I had on hand.