With the frame assembled it is a whole lot easier to visulaize and plan the positioning of the Pixhawk flight controller and the rest of the components. Once the planning process is completed, remove the top plate to begin mounting the components. In this quadcopter build, we began by mounting the motors to the booms. Positioned the battery. And then mounted the Q-Brain 4-in-1 ESC, power module and the telemetry radio to the bottom plate (below photo). To mount the ESC and telemetry radio we used some strong double sided tape which worked out very well.
The top plate of the frame became home to the Pixhawk flight controller, I2C splitter, the GPS, the safety buzzer and the switch (below photo). For the switch we made a special mounting block out of styrofoam covered with black electrical tape. The electrical tape is just to help things blend in, rather than have a white styrofoam block on our quadcopter that would stick out like a sore thumb. Again, we used very strong double sided tape to mount the components, except for the GPS and flight controller, for those two components we used foam weather stripping. Since the weather stripping is only sticky on one side, we added the double sided tape to the non-stick side of the foam. This provided us with both a secure and vibration dampening mount for these two components. (Gotta love when a plan comes together! Snoopy happy dance!)
On the underside of the top plate we mounted the Turnigy radio receiver and PPM encoder using the same double sided tape. To help keep the antenna positioned we secured it with an elastic wrapped around the receiver (above photo). We also fastened the GPS cable and switch wiring with black electrical tape so that they wouldn't get caught when the battery is slid in or out.
To dress up the looks of your quadcopter even more make a really cool custom canopy from a soda bottle.