Thing Files helps you to upgrade Ender 3 x-Axis guide from original rubber bearing to MGN12H linear ball bearing rail.

This Thing includes:

• Track installation guide. Useful to center the rail to the X-axis profile
• The belt anchor prolonger to keep belt aligned whith recess profile
• The side block to prevent the moving block goes off the rail

BOM:

• 1 x MGN12H 300 mm linear guide (track and rail)
• at least 3 x T-nuts with 3MA thread and socket head screws for the track
• 4 x 3MA countersunk head screw to fix the block to the plate
• 1 x 3MA T-nut and socket head screw for the side block.

You have to make four countersink holes in the X-axis plate

This upgrade reduces the service time and makes more rigid and precise the x-axis.
It really works for me!