SummaryIt allows you to have the spool mounted on the top of the i3 frame. InstructionsI have used some wood leftovers that happened to be 6mm thick, glued together. And though I am positive there are tens of bearing holders for filament spools, I designed my own, as I thought it would be quicker. My spools have an opening of 32mm internal diameter approx. Though I have used wood, I have created a plastic version in case you want to print it too. I have added a new support piece that will print into a stronger part, it only changes orientation.