KDE Direct KDE13218XF-105

The KDE Direct KDE13218XF-105 is a heavy-lift outrunner for large multicopters. KDE Direct is a US manufacturer of drone drives. The stator class 13218 stands for 132 mm diameter and 18 mm height; the motor has 36 slots and 42 poles (36S42P), weighs 2,015 g (2,120 g with cables) and measures 150.2 x 55.2 mm. It sits at the upper end of the KDE multicopter motors and is designed for 35.5-inch propellers.

At 105 KV the motor turns roughly 6,400 rpm unloaded on 14S with a LiHV pack (60.9 V fully charged). The pole count gives high torque at low speed. For 180 s KDE quotes 9,135 W at 150 A, which is exactly 150 A at 60.9 V, and only with at least 5 mph (about 8 km/h) of airflow over the winding. Permitted cell counts are 6 to 14S, and the recommended propeller is the KDE 35.5x12.1 two-blade.

KDE measures the maximum thrust of 29,419 g on a test stand at 3,500 ft altitude (about 1,070 m) at 20 °C, with the KDE-UAS125UVC controller at 100 % throttle, 58.8 V (14S), 120.3 A and 7,074 W. That gives 4.16 g of thrust per watt; in a hover at part load the figure is usually much higher. The sea-level value of 32,263 g is an extrapolation by KDE, not a measurement. Because KDE measures at 3,500 ft, these figures are not directly comparable with test-stand values from other makers. On 14S the battery matters too: it exceeds the 160 Wh limit for passenger aircraft from about 3 Ah.

At currents up to 150 A, cables and connectors carry the main burden: poorly crimped contacts heat up and melt. The bearings take the thrust of a 35.5-inch propeller and the shaft the bending from imbalance; both should be checked after every hard landing. Without airflow, for instance in static thrust on the ground, the winding overheats quickly, because the 180 s values assume airflow.