Here is a couple of different angles of the full unit. There is a clear disk with graduated black line on the circumference of the disk. This setup is cheaper to use than use a stepper motor. But I can't find the reading unit anywhere. I can find units with wider slots something like .250 inch wide the one I have has a slot of .070 inch wide. I don't know if this will help you or not. But thank you for your response.
