For dual spool holders you'll need... Vitamins: 1x IKEA 365+ container (103.930.64) with lid (303.930.63) 2x 160mm M8 threaded rod - that should be a press-fit 4x M8 nut and preferably some threadlocker ("Loctite") 2x M8 washer 16x 625ZZ ball bearing 1x Baseplate, e.g. thin plywood - 258 x 150 mm² with chamfered corners ("Bearing Block" version only) Glue ...and a 9mm drill in case you want to use the same two E3Dv5 Bowden couplings I used. Printed parts: 8x "Roller" (try out how the bearing fits into the bore) 8x "Spacer" (try out how firmly they clip into the arms) 4x "Arm 1" 4x "Arm 2" 2x "Full Base" OR 4x "Bearing Block" and the baseplate mentioned above