Bungee has the advantage that it gives very smooth force, and the max force level can be easily tuned.
Below drawings show the setup. The rudder pedals still have the differential brake functionality.
The base of the rudder pedals are two metal bars, that hold the pedals.
All pivot points have ball bearing. Double 8mm diameter bungee
provides sufficient counter force.
Detail of the toe brakes.
Toe-brake assembly: I took these out of a junked gamepad. It is mounted such
that the pedal pushes the lever.
The rudder pedals drawings are made with Google Sketchup. You can download the CAD file here. The file is build-up from several groups, so you can take the unit apart and check the dimensions of the various components.
The rudder pedal unit is screwed at the front of the Modular Simpit. The rudder and L/R toebrake potmeters are interfaced to MJOY-16 unit.