This is my mod for linear rails on my tronxy X5S , but it can be applicable to any other core machines.
I used all the parts from the original X5S for bearings (same size that's fond in the wheels, I think they are "626" or 625").
Personally i am using 2x 500mm long rails, and one i shortened it at 480mm.
You will need lot of M3 and nuts.
I tested everything and works for me, works very well for me.
Edited a few files that where not just right. =P Fixed the issues
To hold my hot end, I using this part (my blower was this model for long time too, it will fit if you are not using the direct drive.