Abstract: A decurling apparatus and method to decurl a substrate in a xerography machine. The invention combines a decurling apparatus having a penetration roller with a small diameter penetrating into a belt. The penetration roller is adjustable and as it pushes into the belt, more decurling of a copy sheet will occur. A controller determines the amount of decurling that is necessary and sends an electrical signal to a driver which operates the penetration roller. The penetration roller is either pressed into or away from the decurling belt. A cam shaft is turned by a motor to cause the cams to move the penetration roller. Although the controller stores the information on the cam location, a home sensor is required to indicate home position. The cam shaft is returned to home position before adjusting the penetration roller to a new level of decurling.