How can I ramp the roll of my mesh based on input axis

Hi all I have created a flying scene.

I want my ship to roll slightly when the axis gos left to right.

Currently, I am taking the Yaw Axis and Multiplying it by 45 and setting the relevant rotation of the ship mesh and not the spring arm. It works fine but I want the ship to roll slowly, like ramp. Currently if I flick the joystick the ship flicks as it would.

My current solutions I am trying are to starting the multiplier at 0 then increasing it by an amount whilst it is less than 45. This works OK and if I keep going will probably work.

Is there an easier way is my question really, or is going to be a complex algorithm like I am producing?

Thanks in advance.