So I was trying to build a quadcopter to sell retail. I built an awesome one that was about 330mm from motor to motor, sporting 10.5 inch props that almost touched each other. It could lift 1 kg, but when I took it to a distributor, he was unsure... He thought it was awesome, but too big, really scary and too pricey. *shrug* So I went smaller, less aggressive, less scarier, and less $$$.
This quad is the result, built with experimentation in mind. Lots of places to mount sensors, lights, etc. The dome can be customized to fit your mood, or you can stack an extra level on for GPS, a Raspberry Pi or what-have-you. I also designed a GoPro (or similar) mount to fit this frame. Flying fabricated flexible filament feet feel free... Wow... Something happened to my brain there.