A string potentiometer has been interfaced to the rudder mechanism. Although not cheap in comparison to the other conventional potentiometers available in the market, the ease of use, smooth movement, accuracy and time it takes to implement the system outweigh the expense.
The potentiometer was purchased directly from the CALTSensoR store on Alibaba – linear position 0-10K ohm output (model CWP-S500R), 500 mm string length. Their sensors are advertised as requiring voltage to operate, however the 0-10k ohm potentiometer can be directly wired to a joystick interface board such as a Leo Bodnar with no additional current required.
It took less than 5 minutes to mount the potentiometer onto the rudder mechanism (substituting where the original LVDT sensor would mount) and to secure the string.
Flaps2Approach also has a good write up on String Potentiometers and if they are worthwhile.