This is a spool-holder as promised in the title. The one i printed is made for carrying a spool with a diameter of 20 cm (or 8 inches for those who is not european).I got this spool from a regular hardware store and is the kind that usually contains electrical wire. Hardware stores just throw these away, so just ask the clerk for one and there is a big chance you will get one.Just print two of each part and mount the parts as shown in the pictures.The spool-holder could just as well be plased on either sides of the makerbot as well.Just attach the spool-holder by using som M3 screws that you have left over from building the makerbot.If your spool is slightly bigger or smaller, just resize the files as needed with your favorite 3D software.