balscrews from linear motion bearing and rails, question about sizing

[Boyan Silyavski]

I meant if i mount them on the same plane like you say, i would like a plane square plate to screw to the ball screw nut and the 4 carriages/z/ or 2 carriages /XY/ at the same time without further modifications.

Like this below. Look how they channeled deeper for the ball screw nut and shallower for the square rail in order all to get at the same level at the moving plate that holds them together/ the nut and the bearing blocks.

I imagine there should be combination of sizes when there are no channels, the nut moves freely from below and all are on the same plane for the plate? Or no?