Building a 1/2 Scale Prototype
Frame
The idea is to build a 1:2 scale prototype before starting with the real thing to gain some experience with the flight controller, the Ardupilot software and all the required technology. Since the real FlyRider will become 2 meters wide and 2 meters long, the prototype will become 1 by 1 meter. The frame is built from 15 mm aluminum square tubes.
Motors
Motors for the prototype are EMAX MT-2216, according to the supplier they shall provide 0,95 kg of thrust with a 10 x 4.5 prop at 14,8 V (4S) and 14.6 A. The real FlyRider aircraft is planned to have a 1,5 / 1 thrust to weight ratio. With a total peak thrust of 5,7 kg the weight limit for the prototype is 3,8 kg to achieve the same thrust to weight ratio.
Speed Controller (ESC)
As motor speed controller (or ESC = Electronic Speed Controller) I use a Hobbywing X-Rotor 20A ESC. Since the EMAX MT 2216 consumes 14.6A at full power, a 20 Amp ESC should be sufficient, especially since no long duration flights are planned with the prototype.
Batteries
As batteries I need a set of 4S Lipos (14.8 V) which can at least provide 45 A to be able to use one Lipo for 3 motors. A 5000 mA battery is able to provide 45 A for more than 6 minutes, enough time for the planned test flights. Make sure that the batteries have the C rating to be able to provide the current needed to get full thrust out of the engines. The C rating, quite simply, refers to the capacity of energy the battery can safely discharge, represented as a multiple of its overall capacity. Thus a 5000 mAh 20 C battery should be able to provide 100 Amp peak current (5A * 20C = 100A) - at least in theory. It is best to have a discharge rate overhead of 30%. For a 5000 mAh 20C battery a discharge with 45 Amps should be no problem.
Flight Controller
My coice for the prototype is a PIXHAWK 2.4.8 controller running the ARDUPILOT software.
Parts Required
6 x EMAX MT 2216 motor (or similar) 6 x Hobbywing X-Rotor 20A ESC (or similar) 2 x 5000 mAh LIPO with min. 20 C (or similar) 1 x Pixhawk Flight Controller 1 x GPS module
Masses
1 x frame alu 15x15x2 mm with fittings 1.5 6 x EMAX MT 2216 motor with prop 0.6 2 x 5000 mAh LIPO 0.8 6 x ESC 20A + 1 x flight controller 0.2 1 x flight controller battery + BEC 0.2 ============================================ Total in kg 3.3 -------------------------------------------- Weight limit 3.8 Margin 0.5
Prototype hardware is complete and ready for flight...
