This is a design for an adjustable roller linear bearing for Flsun QQS/QQS PRO printers.
Now your bearings will fit correctly always. Enjoy.
https://www.youtube.com/watch?v=P5XZPhLkeGk
Technical
12 - 683ZZ bearings per assembly (36 total per machine)
12 - M3 nylon lock nuts
16 - M3 x 6mm bolts
4 - M3 x 14mm bolts
Assembly video here: https://www.youtube.com/watch?v=P5XZPhLkeGk