Bearing improvements using the original Ender 3 spool holder

I had some occasional underextrusion but did not want to bother printing an entire spool holder from scratch, so i re-used the existing one on my Ender 3 Pro and fitted some bearings into it.

The First image shows the entire idea, just press fit some bearings into the existing spool holder and mount that onto the existing plate. 

This requires drilling a new hole, thats the only not reversible change but does not affect the original fixture.

Additional Hardware from your local hardware store (See image #2)

• 2 Ball Bearings
• M8 Bolt, 120mm
• 1 matching washer
• 1 matching nut
• 1 matching self-locking nut

These are the steps:

• Print 2 of the WasherSpacer.stl, (8 minutes print time) they are designed to fit around that washer and into the original spool holder tube
• From the end where the tube is not mounted:
  • Image #3: Push one assembled washer as deep into the tube as possible
    • this might require some force, partly screw the regular not onto the bolt and use that
  • Image #4: Push the other assembled washer into the tube, but only a few (~5) milimeters. When you put the nut onto it, it should stick out, so the plastic tube will not rub onto the bracket later!
• Image #5: Screw a hole into the bracket
• Image #6: Mount the bracket and assemble. Place the washer between bolt head and bracket, stick it through the bracket and fix it with the regular nut. Now slide the tube onto the bolt and fix everything with the self-tightening nut. You are done (Image #7)
• Optional: (another ~15min print time) If you want to prevent the tube from sliding, also print the WasherSpacerSpace and slide it onto the bolt before the last nut (Image #8)

If you mount the whole thing to the very left end there is a minor drawback due to re-using the original bracket. Its not high enough, so some larger spools can touch the threaded rod when sliding to the side. 

Either mount it more to the middle, or (thats what i did) just bend the bracket a little so the spool leans onto it.

Happy Printing.