Thanks to Thingiverse and flykarli, I found the stl file to print an emergency gravity gear extension handle for the simulator. Although it is possible to integrate a mechanism with a rotary encoder to simulate manual gear extension in case of gear failure inhibited, however I think current status of FSUIPC does not allow a manual extension, so for now it is installed on the pedestal as a dummy (visual only). If I can work out a logic with FSUIPC offsets I will definetly take the time to change it to a working way.
I am using PLA in my 3d printsi my layer heights are 0.15mm, infill density %40, i print PLA are 200oC with a build plate temperature of 85oC, which gives quite good results.
The files can be downloaded from this link.