I recently bought some AMZ3D filamaent and, what, the spool doesn't fit the spool holder. The center diameter of the spool is too small to fit. So I remixed another design to make this one. I put in 3 bearing spaces to make it versatile for size. The standard size will fit just fine and the smaller AMZ3D size. I haven't tested 1/2kg spools but anything with a 30mm center diameter or more will fit.
The holder slides on to the side just like the standard holder does. I designed it to fit tight so you may want to sand the back a little bit if you are struggling to get it on. I tried a design with a looser fit and it sagged on me. This one is tight and sits straight.
The black bearings came from a batman spinner that I stole the bearings from. Looks very nice.