I needed a spool holder for the Rigid Ink 1kg spools as they have a larger hole (54mm) and wider body (74mm). This spool holder will hold a spool with a body up to 76mm. The Innofil/Ultimaker spools do not fit this holder, but it is as easy as the original to swap out. I took the original file from the link in the acknowledgement section (Roland Benner) and tampered with it to fit my needs by adding a thin base and an end cap, which means hardly any support needed at all now and adds more rigidity to the structure.