Wanhao i3/plus/whatever fits. Spoolholder with bearing!

thingiverse

Tested! all parts fit. Just what you need is right here. Bearing specs: Outer Diameter, 28mm. Inner Diameter, 11.94mm. Width, 8mm. This design can be printed in PLA, plenty strong! The forces are carefully balanced to pull and compress with ease. The bracket connecting to the bearing is designed for maximum strength and simplicity. Not only does it fit snugly into the bearing, but also has a protective lip that covers the outside for extra support. Why do you need this? The standard spool holder just isn't good enough, and the friction between the spool and arm can cause gaps or uneven layers in your prints. With this version, even a heavy spool is easy for the extruder motor to handle. It's also easily scalable for large spools. All files are uploaded here to make adjustments and modifications as simple as possible for everyone.