Mounting Linear Bearing Rails

Mounting linear bearing rails correctly for long, linear servo motion systems can make or break your project. The rails need to be kept parallel, straight and flat as well as making sure there are no vertical offsets between rails.

You will want to take advantage of the ground reference or datum edge available on most commercial rails. Machine a reference edge on the mounting surface to align the primary rail reference/datum edge. If using another parallel rail, you can mount the connecting plate between them and “float” the other rail, fastening it as you move the bearings down the length of the rails. Otherwise, machine another parallel reference edge parallel to the primary one.

Also, make sure the mounting surface is machined flat per the manufacturer’s specifications and if using two rails, that there are no height differences between the two surfaces.