According to aspects described herein, there is disclosed an apparatus for de-skewing substrate media in a printing system. Each of the support units includes two support frames. After reaching a functional operating temperature, the oxygen sensor provides a signal that is used as an adaptive calibration tool which allows the electronic control unit to calibrate the ion sensor signal and use that signal for controlling the airfuel ratio during cold start operation. Next, a softer 50 Shore A silicone is juxtaposed against the first shot of silicone and it is pressed using a hot mold finishing tool wherein a substantial portion of the cavity is filled. The shoe attic is pivotably attached to the mounting base via two mounting hinges on both flanges.