Yet another spool holder

Designing a spool holder for your 3D printer is probably a right of passage. This is my 3rd, and by far the one I'm happiest with.

**Materials:**
* 4x 608 skateboard bearings
* 8x 3/8" nuts
* 2x 3/8" threaded rod roughly 6.125" (155mm) in length each

**Instructions:**
* Print two of the rollers
* Print two of the sides
* Press fit some 608 skateboard bearings into the circular holes in the sides
* Press fit a 3/8" nut into each end of the rollers
* Thread the threaded rod through