Half Scale Prototype

Why buid a 50% Prototype?

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.
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.

    
    Parts Required for Prototype 

    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 LIDAR

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.

Pixhawk Flight Controller

Initially “Pixhawk” was a student project at ETH Zurich. Little did the team know that it would end up having such a large influence on the drone industry. Today pixhawk is one of the leading flight controllers for UAVs and drones.

    Weight Estimation 

    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    0.4

    ============================================
    Total in kg                             3.3

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    Weight limit                            3.8
    Margin                                  0.5