Hi Friends I started my New quadcopter diy project
self designed frame
config

1000kv motor
30amp simonk flashed esc
apm 2.5 board
8 inch prop

570 mm motor to motor dimension
12mm aluminum square tube for arm
3inch*3inch acp sheet for center plate

here is some pictures

very nice sir

Look awesome! and big too! 

Just to be on the safer side, I suggest you use rubber/silicone PCB dampers at the APM's mounting points. Even though you've used nylon screws, they could still transfer potent shocks to the APM in an even of hard landing or crash.
I almost lost a KK 5.5 in a hard landing.

Thanks
in my new quad I am using such type of dampening