The EMAX ECOII 3520 is a high-efficiency, fixed-wing and large multirotor brushless motor built for long-range FPV platforms, UAVs, and cinematic builds running 12"–15" propellers on 4S to 12S battery configurations. Built around a 12N14P stator with a compact Ø42.5 × 72mm profile, 6mm steel shaft, and 25×25mm 4×M3 mounting pattern, the ECOII 3520 features enamelled wire leads terminated with male 4.0mm banana plugs for secure, low-resistance ESC connections. Four KV options from 330KV to 770KV cover everything from high-voltage 12S long-range builds to efficient 4S platforms.
Key Features
Stator configuration: 12N14P
Available KV ratings: 330KV / 495KV / 560KV / 770KV
Optimized for 12"–15" propellers on 4S–12S builds
6mm steel bearing shaft with CW thread
M6 prop adapter shaft thread
25×25mm — 4×M3 mounting pattern
Enamelled wire leads (95mm) with male 4.0mm banana plugs
Motor mount included for easy airframe integration
Precision bearings and anodized finish
Multi-strand winding for smooth, efficient power delivery
