Spool
Attached stl files of the spools help feeding the material well.
The spool can be printed and assembled as shown in the attached photo. The bearing used is 623zz (3x10x4mm). Bowden(PTFE) tube(inner2.0 outer 4.0, 80cm) is used for each spool. and M4 nut was also used. You can check how to use it from the picture below.
After assembling the M4 nut, you need to widen the inside of the tube for preventing friction.
