This is the Dash8 Q400 autopilot panel (FGCP) I designed to operate with an usb interface for FSX (I used the bbi-32). I don't have any specific build instructions. I have used square tact switches (aprox. 6mm) for the buttons and rotary encoders for the knobs. The tact switches are glued in the squares of the tact switch panel using hot glue. The tact switch panel is then secured behind the front plate using screws. Screw holes are not designed so you can drill your own according to your preference. One rotary encoder is glued in the pitch wheel base (pitch wheel rotary encoder holder). The pitch wheel base is then glued in the tact switch plate. The front plate is then secured to the FGCP box with screws (drill your own holes again). Letters are printed on the plate and the buttons and can be painted for better looks. The knobs I used are just generic rotary encoder knobs I found in thingiverse. I have used hot glue everywhere because it is strong enought yet easy to unglue clean up and correct any mistakes. NOTE: Buttons might have scaling issues.