After reflection on my process designing the flippers I have decided that using two voltages in two wires is an inefficient way to solve the problem. I will instead use PWM through an Arduino to vary the voltage through a single wire.

I have created a complete CAD of all the components of the pinball machine. My next steps are to manufacture each component and edit them unit they suit my needs. I will also create the electronics.
CAD for full pinball machine
Aesthetic plan