The joysticks used in games and modeling contain two potentiometers with a resistance of about 100 kΩ, which turn through 60 to 90 degrees. In fact, only one third to one-quarter of the total resistance is used in these potentiometers. The diagram shown here should be used when making your own joystick with ordinary potentiometers that turn through 270 degrees. The values for R1 and R2 are given as guidelines only
and their optimal value should be found through trial and error.
It will be easier if you temporarily replace R1 and R2 with a combination of a fixed resistor and a preset since it can be a time-consuming job to determine the correct values; this is because of each of the resistors affects the other.