[EN] Bosch Rexroth: Linear Guides - Mounting and aligning parallel guide rails (How-To)

Mounting and aligning of parallel roller rails.
Parallele Rollenschienen montieren und ausrichten.

[MrJesus]

I understand the parallel part, but how do you know your reference rail is straight?

[charleshaerle]

But how do you align round rails that are mounted on the side of the extrusions when the rails are 30 inches apart?