Lightweight GoPro Hero 3 for FPV Flying

I designed what's called a naked GoPro - A stripped down, lightweight GoPro powered by an external power source. In this case, I remade and improved the GoPro Bones but used a GoPro hero 3 instead. I wanted to improve on the GoPro Bones by further reducing weight and also make it fit my specific 3-inch drone. While the GoPro Bones is light, it is not light enough for my drone, the DarwinFPV Babyape. My design not only fits my drone perfectly, which the bones could not (without 3D printing extra parts that would add weight), but my design is also extremely lightweight as I removed about 55 grams.

Materials:

• GoPro Hero 3
• Drone (This is what will be used to power the camera)
• Glue
• 3D Printed Camera Case
• Wire

Tools:

• T4 Torx Bit along with a screwdriver set
• Soldering Iron + Solder
• Calipers (Optional)

Optional:

• CAD Software (If you would like to design your own case for a different camera)
• External Power Source (If you want to power the camera a different way)

Disassemble GoPro

First you want to disassemble the camera, in my case, I used an old GoPro Hero 3 Silver Edition I found lying around. Using the T4 torx bit and screwdrivers I had, I was able to disassemble the GoPro down to the motherboard and camera sensor. Note: Photos are from IFIXIT and IFIXIT has a very thorough guide on how to do this:(https://www.ifixit.com/Teardown/GoPro+Hero3+Teardown/12457)

Design the Case and Mount

After disassembling the GoPro, I used a pair of calipers to accurately measure the sizes of parts and location of them, such as how big the recording button is and where it's located on the motherboard relative to other parts. Then, using those measurements, I began designing a case and mount for the electronics. I eventually came to my final design after 6 iterations (My first design for a case is provided in the picture). I designed the parts in CAD software, so anyone can recreate this project with just a computer, but the specific files for the GoPro Hero 3 are provided. The mount I used was designed for the specific 3-inch FPV drone I'm using, the DarwinFPV BabyApe drone. Then, I designed the case around the idea of being lightweight because I wanted to mount this to a 3-inch drone, one with less power than traditional 5-inch FPV drones.

Diving into the specifics about the case and mount, I first traced the outline of the top of the drone, using it as a reference for the mount. I then added two support arms on either side of the mount to allow the camera case to rest on. Next, I added holes going through both arms so that a pin could be inserted, keeping the camera case in place as well as another locking pin going through the main pin to keep it from slipping. As for the case, I began by taking a picture of the motherboard and tracing it. I designed a simple box with a button to enclose the camera, but this, however was heavier than what I wanted. So over time and throughout different designs, I was able to reduce to weight significantly while still keeping the strength of the original box design.

Get Case and Mount

I 3D printed these using my Ender 5 Pro, and used PETG filament at 50% Infill (the photo shows my settings in Cura as well as the orientations of the parts). You could 3D print these yourself if you have a 3D printer, if not, you could use a 3D printing service that will 3D print things for you, such as ShapeWays. (https://www.shapeways.com/)

Assemble Mount and Case

Since I am using the Darwin Baby Ape 3 as my FPV drone for this project, putting the mount on to the drone is very simple. I unscrewed the 2 screws on the top of the drone that were located in front of the battery grip tape. Then, I put the same screws through the mount and back into the drone, securing the mount into place. As for the case, I simply pushed the camera into the case, which has a good friction fit, then further secured it with some hot glue. I then glued the Bluetooth and power buttons to the outside of the case.

Solder to the Camera

Next, you want to solder some wires to the camera to power it. I used red and black wire so I could easily distinguish between the power and ground however, this is not necessary. I soldered red wire to the right pin, black wire to the left pin (shown in photo), and left the center pin empty as it is used for a temperature sensor inside the old lithium battery.

Solder to the Drone

I then soldered the wires coming from the camera to their respective places on the drone flight controller (shown in photo). In the flight controller diagram, I have circled as well as pointed to the pads I used (5V and GND) with the red wire going to 5V and the black wire going to GND. After soldering, I made sure to power on the drone and make sure the camera was receiving power too as well as being able to record.

Fully Assemble

After testing that everything works, simply put the camera onto the mount. I rested the case on the mount, then lined up the holes and put the main pin inside. Then, I put the second pin in and finished the build. The exploded view (picture) provided may help with understanding what goes where.

Have Fun!

After this build, hopefully you'll have a fully functional camera mounted to an FPV drone that you can fly.