Still need more on the whole mechanism, so far, most has been guess work!I just wish it was warm enough to rain! The 555 timer is part of a control circuit and the 555 stops the motor when a coupon has been dispensed. There is a light sensor that detects the end of a coupon on the roll. The motor is restarted by the operator when a coupon has been picked off.
First you say a 555 timer controls the motor then that the operator re-start it?
Also is the motor driving the drum of coupons? If so then the surface rate of the coupons will vary as the drum gets smaller for a given 555 time.