SunnySky XS X6215S KV170

The XS X6215S KV170 from SunnySky, a Chinese maker, is an outrunner of the XS series for heavy multicopters. The type code 6215 stands for a stator diameter of 62 mm and a height of 15 mm, and the layout has 24 slots and 28 poles. The maker assigns it to aircraft of up to 3.5 kg take-off weight per motor.

The motor weighs 375 g and its KV is 170. On 12S at 50 V that works out to about 8,500 rpm at no load. The recommended propeller is the 22x6.6; with it the motor reaches 10,050 g of thrust at 50 V and 43.5 A, more than 26 times its own weight. The continuous current of 43 A and the power of 2,175 W apply for 30 s; the 2,175 W match the 43.5 A of the test point at 50 V. These values cannot be compared with figures resting on 10 s or 180 s.

At 3.5 kg take-off weight per motor, a quadcopter of 14 kg and a hexacopter of 21 kg stay below the 25 kg limit of the EU open category; an octocopter of 28 kg exceeds it and needs an operational authorisation in the specific category. Below that, C3 and C4 apply, and Remote ID is mandatory for C1 to C3. A 12S battery at 44.4 V nominal passes the 160 Wh air-transport limit from about 3.6 Ah.

In selection the calculation starts at take-off weight: at 3.5 kg per motor the hover sits far below peak thrust, leaving reserve for gusts and manoeuvres. The ESC must handle 12S and the 43 A with headroom. Check the bearings, the winding insulation under sustained heat and the rotor bell after hard landings; a 22-inch propeller loads the bearings heavily when unbalanced.