We currently use two 2 finger-140 grippers on a robot to move cup holders for a Toyota Rav4 in and out of a work station, The first side hands 2 cup holders to an operator who runs it through a clipping procedure, they are then placed in the other side of the work station and it checks the parts for completion. After the check passes the part slides back and the UR picks the parts from the inside of the cups. We had no problem until this week picking the cups and now the grippers have been polished smooth by the first station where the operator pulls the cups off of the grippers. When the UR enters the cups the grippers are in the closed position, it plunges to depth and opens the gripper to pick the cup holder. then lifts out of the nest and moves them to another location. As they lift one of the cups is falling off the gripper, and even setting the gripper force seems to have no impact. I am now wondering if these grippers only account for gripping force on the closing motion and not the opening motion? If so is there any way to increase the opening force of the gripper?