Hi Asim,
Thanks! My Ranger EX was one of my VTOL experiments that failed. I did not like the size and awkwardness of the final VTOL design and did not get it to perform properly a few years ago using the initial APM VTOL firmware implementations. Since then, I have configured my Ranger EX back to an APM plane and it works perfectly as a long range flyer but it does require a runway. You can read about my initial setup here and here.
The stock Ranger EX power system was adequate but required a relatively long take-off when loaded with a big LiPo pack and camera.
Stock Ranger Setup on 4s
Stock Motor: 3715 outrunner 1000kv
Stock ESC: 40-amp with BEC
Stock Prop: 10x6
Battery: 4s 8AH Nano-Tech
I upgraded to the Turnigy SK3 3542-1250kv motor with the same prop and 4s 8AH battery but using a heavy duty 80-100 amp ESC. This combination provides 746 watts at 51 amps using the same 10x6 prop. It gives you just enough extra power for take-offs and still sips the current during normal flight. The larger ESC stays cool inside the fuselage.
So where did my quad power system for the Ranger EX go? Into my FX-79 QuadPlane. It also uses the same forward flight power system as the Ranger EX. The FX-79 initially gave me problems with tucking but they seemed to disappear after stiffening the wings and flying in reasonable winds up to 15mph. The FX-79 breaks down quickly and is easy to transport in its box frame.
The APM firmware has matured nicely for VTOLs. It is feature-rich which also comes with its share of parameters.
Cheers!