There are 3 cutting motors on the RL2000, there is no real need to control these independently, therefore they will be driven from a shared output. The temperature of the motors should, however, be monitored independently. The motors have in built thermistors, therefore can be monitored using a resistor ladder with the analogue inputs to the arduino.
I’ve decided to change the design to be more modular, this will allow me to develop the system incrementally, as such I will use a set of stackable boards each board having there own function.
The “top” board will contain the connectors to all of the sensors/drivers (also containing the main pi zero) as shown in the diagram