EMAX ECOII 3520 Brushless Motor

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

KV / Cell / Propeller Guide

330KV — 8–12S — 14"–15" props (GF14×7, HQ15×10 2-blade)
495KV — 6S — 12"–14" props (GF12×6, GF13×6.5, GF14×7 2-blade)
560KV — 6S — 12"–14" props (GF12×6, GF13×6.5, GF14×7 2-blade)
770KV — 4–5S — 12"–14" props (GF12×6, GF13×6.5, GF14×7 2-blade)

Specifications

Motor Model: ECOII 3520
Framework: 12N14P
Dimensions: Ø42.5 × 72mm
Weight (with wire): 215g
Bearing Shaft: 6mm
Prop Adapter Shaft Thread: M6
Shaft Thread: CW
Lead: Enamelled wire, 95mm, Male 4.0mm banana plug
Mounting: 25×25mm — 4×M3
KV Options: 330KV / 495KV / 560KV / 770KV
Peak Current (330KV @ 12S): 52A | Max Power: 2454.5W
Peak Current (495KV @ 6S): 45.1A | Max Power: 1111W
Peak Current (560KV @ 6S): 62.9A | Max Power: 1540.1W
Peak Current (770KV @ 5S): 65.7A | Max Power: 1343.8W

Package Includes

5× M3×6 screws
1× Steel M6 nylock nut
1× Paddle gasket
1× Motor mount
3× 4.0mm female connector