BrotherHobby Avenger 2806.5 1300KV

The BrotherHobby Avenger 2806.5 1300KV is a mid-size FPV outrunner for long-range quadcopters with 6 to 8-inch propellers, the kind built for distance and long flight times. BrotherHobby is a Chinese maker. The hollow titanium shaft stands out, saving weight in a motor of this size.

1,300 KV is a low value for this type of motor: on 6S (22.2 V nominal) it works out at roughly 28,900 rpm unloaded, and on 4S (14.8 V) at roughly 19,200. The lower speed belongs with the large 6 to 8-inch propellers the maker recommends. The stator measures 28 mm in diameter and 6.5 mm in height; the large diameter lengthens the lever arm and so raises torque, while the low height keeps the weight at 41 g with short cables. Permitted cell counts are 4 to 6S.

Because the same motor may run on 4S and on 6S, the cell count sets the operating point: with fewer cells it turns more slowly and more current flows for the same power, with more cells it turns faster at lower current. Speed controller (ESC) and battery must match the chosen cell count. Long-range flying also calls for attention to the rules: in the EU open category the aircraft stays within sight of the pilot or an observer, and the class from C0 to C6 depends on the take-off mass of the whole drone, not on the motor.

Long-range builds fly for minutes under load; heat collects in the winding, and the insulating varnish ages faster than in short racing flights. After landing the motor should feel warm, not uncomfortably hot. Bearings should be checked for roughness and play, the shaft for true running: rough bearings and a bent shaft show up as humming and vibration that also disturb the flight controller's motion sensors.