I liked Hiro's foldable bracket, but I had 2 things I wanted to address:

1) It uses the metal spool bracket that came with the X1c, and I have some tiny 250G spools from SUNLU that didn't fit over it, nor do they fit in the AMS. So I created a printable spool arm using a design that I originally created for a 3DPN contest.

2) The base is a bit loose with the fit and when you put a spool on it, it tilts down a fair amount. So I addressed this by making it slightly thicker and the base portion taller to take up the slack so it doesn't tilt downwards now.

I also put some pockets in the parts for 5MMx3MM magnets. These keep the arm upright when not in use. (Just make sure to place them with the right polarity!) They don't cause it to ‘snap’ up in place due to the ~10mm gap between the two parts, but they keep the arm from falling down when not in use.