Filament Spool Holder for Prusa XL

This is a mod of the Prusa XL spool holder remix. Two changes have been made:

• Added bearing retaining tabs to hold the 608 bearings securely in place.

• Added a low-profile version for filament spools with small center holes.

All other hardware and mounting remains the same as the original — M4x12 screws and M4nEs nuts into the 3030 extrusions. No supports needed for the XL mount. Rollers are printed standing up with some supports at the base.

Each spool holder still requires two 608 ball bearings.