Potentiometer to control electric over hydraulic controls

I operate a Wireline Truck in the oil and gas industry. Essentially we have a very long spool of cable that is ran with a hydraulic motor. The hydraulic motor is controlled by a bidirectional single axles potentiometer joystick. It’s a 12v system. We run from speeds from 10 meters per minute all the way too 300+. Occasionally we need to go all the way down to 2 meters per minute but many of our trucks cannot. Can we add in a potentiometer dial next to the joystick that could reduce the voltage less when needed to go extra slow?

I hope this makes sense!

Welcome to the Technical Forum. Well I would say yes you can add more resistance and that would reduce the voltage and current so it would slow the speed. The bad part is what is the resistence of the potentiometer needed to do that? We would need a value and wattage you would need to find a part number.

Would you need the information from the joystick that is installed already and/or the valve coils at the motor?

I am actually not sure how to calculate for the resistance you would need on this. There would have to be a calculation made on what voltage and current are after the joystick. Then what the end voltage it needs to be when the speed is the extra slow.

One would need to understand the design of the system and any limitations of its components in order to make progress on such a thing; there may be valves/pumps/etc. that do not operate reliably below some minimal speed, or the system may employ a near-zero dead band to ensure that things are well and truly stopped when meant to be stopped. Might be something else. Regardless, you’d need to understand why the system behaves as it does before a workaround could be developed.