My very first quadcopter has been sitting in my closet for many months, it slowly became obsolete as I upgraded my transmitter (controller) from Spektrum, to Frsky, and now finally to Crossfire.
As I've built more and more quadcopters, I've accumulated quite the collection of spare parts. Things upgraded and not used any more, or things from an assortment of spare parts that I haven't yet needed.
I decided to use all of these parts, plus one new one to upgrade my DIY 450mm Quadcopter (Link: https://blog.briancmoses.com/2017/03/...) into something I could use with my current stable of 6S batteries (I hope!)
I also decided to go ahead and make a few other improvements:
I upgraded the flight controller to something more modern.
I added two GoPro Session mounts (one pointing forward, one pointing down)
I added an FPV camera pointed forward for piloting
I added an FPV camera pointed downward for bombing
I added a camera switching part, so that I could switch my FPV feed between the two cameras.
This video is a quick introduction to what I've upgraded, and a couple of the first bombing runs dropping things (a dodgeball-like ball) from the quadcopter.