that includes a gear 66 that is attached to the sensor roller 54 in the illustrated embodiment the sensor roller 54 is configured to be driven such that it has a slower surface speed that the drive roller 52 in this manner tension is created in toweling 12 between the sensor roller 54 and the drive roller 52 such that the perforation 16 can be expanded alternatively the sensor roller 54 is not attached to the motor 62 but is configured to be rotated by contact with the toweling 12 in the illustrated embodiment the sensor roller 54 has a centrally formed circumferential ridge 55 disposed between two end sections 56 the end sections 56 have a first diameter and the ridge 55 has an second diameter the second diameter of the ridge 55 is greater than the first diameter and is for expanding the perforation 16 as it passes over the sensor roller 54 alternatively the sensor roller 54 could have a consistent diameter across its full length and could be straight or bowed for expansion of the perforation 16 as can be seen in fig5 the sensor roller 54 is positioned generally parallel to the pinch roller 58 the pinch roller 58 is generally cylindrical and of uniform diameter and includes a plurality of sub rollers 59 the pinch roller 58 is also connectable to motor 62 via the transmission referring now to fig3 and 4 the motor 62 is mounted on one of the side walls 26 and is configured to be powered by a battery 68 the motor.