Then when my A1 arrived and I saw the spool holder, I had an idea. This is basically a little cross section of the upper rail on an A1 with provisions added to attach it to the wall. I think it's a slick little setup compared to just a printed spool holder screwed to the wall as I had been using before. The pivoting fitting means the PTFE tubing isnt dragging on the spool and should aid in smooth feeding. Happy printing!