The present disclosure relates to methods and apparatuses for controlling the relative placement of advancing substrates and discrete components in diaper converting lines. The diapers may each include a chassis connected with front and back elastic belts. In controlling the relative placement of these elements during the assembly process, a controller may change the machine direction speed and/or position of certain elements and cross direction speed and/or position of other elements such as the advancing substrates and components in order to help achieve proper placement and orientation. During the assembly process, the registration features are detected, and a controller may change the machine direction speeds of the advancing elastic laminates and/or chassis and/or may change the cross directional and/or machine direction position of the advancing elastic laminates and/or chassis.