I am currently using my own design ‘H’ frame quad with great success. It has the fore and aft arms mounted on silicone o rings and has very low levels of vibration, both on APM and direct mounted camera. The low kv motors and large props give good flight times. It will probably be OK with a larger DSLR camera but think its time for a bigger machine anyway. My ESCs are rated at 30A but still feel hot when the entire (4 motors MT4008) are only pulling 20A.
I would like to scale up my machine and go for the ‘H4’ frame again, firstly to use the same vibration isolation system and also because the H frame allows good separation between components like power lines and magnetometer and various antenna. Also the camera can be out front and clear of the frame.
It would be nice to survive a motor/prop/ESC failure without a total frame loss.
Will a hexa on APM achieve this or does it need to me 8 more?
My quad stability seems perfect so I dont know how more rotors could improve it and also one large prop/motor is a more efficient lifter than 2.
Anyway, I am H4 quad biased but willing to be convinced otherwise.