This is how I went about installing a Feiyu-Tech MINI 3D Gimbal to my SOLO.
I would like to strongly emphasize that this modification will void your 3DR SOLO warranty completely and entirely. If you are not comfortable with the voiding of said warranty please do not attempt this modification.
I am not responsible if you experience any issues with your SOLO if you choose to do this modification. This takes a certain level of skill as well as some personal responsibility. Please read the entire how-to before doing anything to be sure you are comfortable with procedure.
Again, this will 100% void the 3DR warranty on your SOLO.
Things you will need:
Feiyu-Tech MINI 3D Gimbal
GoPro Camera (3+ or newer)
Philips head screwdriver
Flat head screwdriver
Soldering Iron w/solder
Small gauge electrical wiring
Some hobby grade electrical connectors
Be sure that SOLO's battery has been removed from SOLO. Then remove the front GPS shroud with a small flat head screwdriver by gentle prying up and forward from the rear of the shroud. There are 4 tabs holding it in place.
Once removed take a philips head screwdriver and remove the 7 screws that bold the battery tray in place.
Lift up and slightly backwards on the tray gently to remove it. You will need to disconnect the GPS connector as well. Set the tray aside.
With SOLO facing you nose first you will see where the battery plugs into the battery board. That board will need to be partially removed so that we can solder the positive and ground wires to it for the gimbal.
On the bottom left side of the board is a small tab holding it in place, use a small flathead screwdriver to pry that tab back slightly. While doing that pull straight up on the board itself. You can also disconnect the smaller electrical wiring running from the battery board to the main board.
You will need to solder some wiring and a connector to the backside of the battery board.
Once done you can then reconnect the small wiring harness and put the board back into position making sure that it is securely in it's place.
Next you need to solder a single wire with connector to the BUS pinout board. This is the connection for the tilt control of the camera.
*Above pics courtesy of Jason Short. Mine look identical expect for I used white wiring.
That completes the necessary soldering for this mod, you can now put the parts you took off SOLO, back on. Before re-installing the battery tray make sure the newly installed wiring is running to SOLO's gimbal bay opening and will not pose a threat to any of the other electronics that may result in an electrical issue.
On the Feiyu-Tech wiring harness you will see a grouping of wires, for this mod you will only need use of the solid red, solid black and solid blue wires. Red = +, black = - and blue = tilt function.
With the gimbal we do not make use of their top mounting plate. The hole pattern of the gimbal plate is fairly close to matching SOLO's plate so you may use the supplied damper balls to attach the gimbal to SOLO's plate. I chose to use a set of ARRIS balls instead as I prefer them over most of the other ones on the market. IMP Concepts is working on an adapter plate for the FY, IMP
Once the gimbal is mounted to SOLO's plate connect the red,black and blue wires from the harness to the 3 new wires and pull them through the center hole of SOLO's plate and to the rear of the gimbal. Check and make sure that you can easily connect all 3 wires and that you have enough left to easily connect them to the gimbal. (These show a white wire coming out of SOLO, it's the same as the single red shown above.)
Once you have established that you can connect the gimbal to SOLO, go ahead and remove the gimbal from SOLO and set it aside.
In order to control the tilt of the camera via SOLO's controller you will need to make some adjustments to it through the use of Mission Planner.
You can use your laptop's wifi to connect to SOLO. Ahmed Agbabiaka made a great video on how to do that