After letting all the epoxied endcaps cure, I was finally ready to put the whole drone together. Starting with the big electronics tube, I connected each ESC with the corresponding wires jutting out of the endcap and also connected the camera USB to the Raspberry Pi. With that, all I had to do was clip the batteries in on the opposite side of the tube and fit the endcaps on.

Although it ended up being a very close fit, with the endcaps just barely being able to fit fully on and requiring some interesting methods to just make them stay on, it ultimately worked out. 

After that, all I had to do was assemble the smaller camera tube, and all the important electronics were good to go. 

Then, to finish off the connection between the motors and the ESCs, I had to find a way to connect the motor wires and the outside-end of the endcap wires. I found some convenient waterproof heatshrink crimps, which were easy and quick to install, despite almost accidentally melting the walls of the drone with a heatgun a couple times. 

I then assembled the final drone. This is what the inside looked like at the front, with the fastened camera module, big tube, and nicely organized wires. 

Finally, there was one more step that I had to take before I could finally do the first test run. In order to account for the unbalanced distribution of weight in the drone, especially with heavy batteries being more towards the back end of the drone, I had to insert some buoyancy foam into the back of the drone. 

Stay tuned for the next update, where I finally drop the drone into some water.