channel such that the extension shaft 54 is able to enter one side and exit the other if required or a semi channel where the channel is closed and would be similar to a groove typically the at least one guide track 50 is permanently or removably attached or integrated to a first or second surface to form a first guide track and a second guide track respective to each surface the cam system operates via the actuator 68 rotating in the first or second direction the rotary motion produced rotates the leadscrew in the corresponding direction and subsequently via the leadscrews meshed relationship to the nut 70 moves the nut 70 linearly along the axis of the leadscrew in the first or second direction the nuts movement causes the arm 72 to move and subsequently the tooth rack 44 both of which move linearly and parallel to the axis of the leadscrew the motion of the toothed rack 44 causes the gear 64 to rotate as well as the shaft 48 a due to the meshed relationship the toothed rack has with each one as the shaft rotates in the respective first or second direction so the cam 48 b.