In various embodiments, an electronic flow selector of a fluid flow control system may be used to select a flow rate of a fluid. The fluid flow control system may be operated in an electronic mode and a manual mode. When the system is in a manual mode, mechanical backup flow selectors may be used to select the flow rate of a fluid. The mechanical backup flow selectors may include a position detection system to determine the flow rate of a fluid. Flow selectors of the flow control system may be rotationally engaged with the valve shafts of each needle valve, while allowing them to translate axially. The flow selectors may remain axially fixed while the valve shafts are axially translated with respect to the needle valves in a fluid flow control system.