Home built quadcopter

So here is my first attempt of building a quad copter. The build is made from discrete parts, that I started to buy since January.
I started with a simple X600 kit for the frame, but I plan to change it using extra long arms (Carbon square rods, that I already bought/have), for improving stability and airflow (less turbulence if motors are further away from the central structure).

I also plan to clean up the wiring in order to minimize turbulence. Eventually I may pass all wiring inside arms. Some screws used for landing gear, make this more difficult to accomplishing cleanly.
Currently I have mounted the entire frame, including all mechanical legs, that use a spring to dampen any stronger landing, and also allows for some skidding, hopefully preventing tilting the Quad.

One of the advantages of this frame, is that it can be easilly folded to a more compact shape, that will make it easier to fit in a car, specially when I increase wingspan to about double the original size, 1200mm (1.2 meters).
I have mounted and correctly centered all 4 engines on each frame arm. Engine connections are still not done as can be seen on the pictures.
I also mounted all 4 ESCs on expected final position. ESCs are 40 Amps, with switching BEC, to prevent heating and avoidable battery consumption, that happens with typical linear BECs.
Something of concern is that ESCs may need some extra air flow to cool off appropriately. If this is the case, I will have to put them closer to engines/propellers, which will spread the overal mass, making the quad less reactive/nimble.
It's better to have most of the mass near the center and below the thrust plane, for better maneuverability and stability.
Next step is to balance all 4 Propellers correctly.
I'm still waiting for the next batch of parts to arrive, namely: Flight Controller, Battery, Charger and power distribution board (I already have a Radio and Receiver on standby :).
After all these items arrive, next step will be to add a camera suitable for taking pictures and videos, and in due time, FPV flight :)