About this 3D model
I really liked the design of randyy's spool www.thingiverse.com/thing:8317. I'm sure the spool works well attached to the clip, but I didn't want to use one of those. I already had a spool holder that holds the spool via a rod, and when I tried using this spool on it, it leaned over to the side. All I did was to add a simple tube that protrudes from the central axle, this gives it the support it needs to remain upright when held by a simple rod.