ECOII Series / 35XX / ECO II

ECO II 3520 Brushless Motor

A high-efficiency 3520-class aircraft motor available in 330KV, 495KV, 560KV, and 770KV configurations for 12 to 15 inch propellers.

330KV495KV560KV770KV

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KEY FEATURES

Designed for FPV performance tuning

Four KV choices cover 4S through 12S power systems and 12 to 15 inch propellers.
Precision bearings, a steel shaft, multi-strand winding, and an anodized motor structure support reliable high-load operation.
A 25 x 25 mm four-hole M3 mounting pattern, 95 mm leads, and 4.0 mm connectors simplify installation.
Verified load-test data is provided for every KV option, including voltage, current, thrust, power, efficiency, RPM, and throttle.

SPECIFICATIONS

Product snapshot

Stator Size: 3520
Series: ECO II
KV Options: 330KV, 495KV, 560KV, 770KV
Motor Dimensions: 42.5 x 72 mm
Framework: 12N14P
Weight: 215 g including wires
Propeller: 12-15 inch
Bearing Shaft: 6 mm
Prop Adapter Shaft Thread: M6
Shaft Thread: CW
Mounting Pattern: 25 x 25 mm, 4 x M3
Lead: 95 mm enameled wire outlet
Connectors: Three 4.0 mm female connectors

VARIANT SPECIFICATIONS

KV configuration matrix

KV	Battery cells	Propeller	Idle current	Internal resistance	Peak current	Maximum power
330KV	8-12S	14-15 inch	0.8 A @ 10 V	88 mOhm	52 A @ 12S	2454.5 W @ 12S
495KV	6S	12-14 inch	1.0 A @ 10 V	39 mOhm	45.1 A @ 6S	1111 W @ 6S
560KV	6S	12-14 inch	1.3 A @ 10 V	31 mOhm	62.9 A @ 6S	1540.1 W @ 6S
770KV	4-5S	12-14 inch	1.9 A @ 10 V	21 mOhm	65.7 A @ 5S	1343.8 W @ 5S

OFFICIAL GRAPHICS

Engineering drawing and specifications

ECO II 3520 Brushless Motor engineering drawing 1

ECO II 3520 Brushless Motor technical specifications
SPECIFICATIONS
Framework	12N14P
Length	72 mm
Diameter	42.5 mm
Battery cells - 330KV	8-12S
Battery cells - 495KV / 560KV	6S
Battery cells - 770KV	4-5S
Recommended propeller	12-15 inch
Weight (with wire)	215 g
Prop adapter shaft thread	M6
Bearing shaft	6 mm
Shaft thread	CW
FEATURES
Precision bearing
Steel shaft
Anodized finish
25 x 25 mm, 4 x M3 mounting-hole pattern
Multi-strand winding
95 mm enameled wire outlet
PACKAGE INCLUDES
5 x M3 x 6 screws
1 x steel M6 nyloc nut
1 x paddle gasket
1 x motor mount
3 x 4.0 mm female connectors

LOAD TEST DATA

Verified performance data

The following measurements are from EMAX load-test records. Results may vary with battery, propeller, environment, and installation conditions.

330KV

GF14 x 7, 2-blade

ECO II 3520 Brushless Motor 330KV - GF14 x 7, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
47.94	1.83	806	87.7	9.19	4154	30%
47.9	4.34	1490	207.9	7.17	5547	40%
47.84	7.48	2244	357.8	6.27	6693	50%
47.76	12.1	3081	577.9	5.33	7779	60%
47.67	18.28	4024	871.4	4.62	8825	70%
47.56	26.63	4880	1266.5	3.85	9726	80%
47.39	37.2	5943	1762.9	3.37	10589	90%
47.22	51.98	7120	2454.5	2.9	11269	Max

HQ15 x 10, 2-blade

ECO II 3520 Brushless Motor 330KV - HQ15 x 10, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
33.32	1.6	573	53.3	10.75	2837	30%
33.3	3.49	1032	116.2	8.88	3730	40%
33.26	6.36	1555	211.5	7.35	4560	50%
33.2	10.23	2115	339.6	6.23	5313	60%
33.1	15.4	2728	509.7	5.35	6043	70%
33	22.12	3421	730	4.69	6692	80%
32.9	30.08	4056	989.6	4.1	7304	90%
32.75	40.56	4793	1328.3	3.61	7880	Max

495KV

GF12 x 6, 2-blade

ECO II 3520 Brushless Motor 495KV - GF12 x 6, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.02	1.27	290	31.8	9.13	3344	30%
25	2.519	550	63	8.73	4395	40%
24.99	4.479	870	111.9	7.77	5451	50%
24.96	7.309	1270	182.4	6.96	6497	60%
24.93	10.97	1690	273.5	6.18	7459	70%
24.89	15.708	2180	391	5.58	8414	80%
24.83	21.766	2730	540.4	5.05	9339	90%
24.76	29.147	3310	721.7	4.59	10231	Max

GF13 x 6.5, 2-blade

ECO II 3520 Brushless Motor 495KV - GF13 x 6.5, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.02	1.585	410	39.7	10.34	3253	30%
25	3.312	760	82.8	9.18	4303	40%
24.97	5.979	1180	149.3	7.9	5320	50%
24.94	9.817	1670	244.8	6.82	6305	60%
24.89	14.723	2190	366.5	5.98	7204	70%
24.84	20.981	2770	521.2	5.31	8078	80%
24.76	29.054	3410	719.4	4.74	8927	90%
24.68	39.063	4100	964.1	4.25	9741	Max

GF14 x 7, 2-blade

ECO II 3520 Brushless Motor 495KV - GF14 x 7, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.01	1.749	460	43.7	10.52	3230	30%
24.99	3.754	870	93.8	9.27	4266	40%
24.97	6.829	1370	170.5	8.03	5255	50%
24.93	11.256	1960	280.6	6.98	6207	60%
24.88	16.959	2570	421.9	6.09	7084	70%
24.81	24.166	3230	599.6	5.39	7908	80%
24.72	33.598	3990	830.5	4.8	8702	90%
24.62	45.124	4760	1111	4.28	9457	Max

560KV

GF12 x 6, 2-blade

ECO II 3520 Brushless Motor 560KV - GF12 x 6, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.01	1.7	400	43.1	9.28	3754	30%
25	3.5	710	86.6	8.2	4927	40%
24.97	6.2	1120	155.4	7.21	6102	50%
24.94	10.1	1580	252.7	6.25	7217	60%
24.89	15.2	2100	377.7	5.56	8277	70%
24.84	21.8	2680	541.4	4.95	9324	80%
24.76	30.1	3300	745.1	4.43	10297	90%
24.67	40.2	3870	992.6	3.9	11202	Max

GF13 x 6.5, 2-blade

ECO II 3520 Brushless Motor 560KV - GF13 x 6.5, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.01	2.1	540	53.7	10.05	3636	30%
24.99	4.6	970	114.1	8.5	4807	40%
24.95	8.3	1480	207.9	7.12	5913	50%
24.91	13.6	2060	337.8	6.1	6969	60%
24.85	20.2	2660	502.9	5.29	7925	70%
24.77	28.9	3360	715.9	4.69	8881	80%
24.67	40.2	4110	991.8	4.14	9755	90%
24.54	54.7	5000	1341.8	3.73	10571	Max

GF14 x 7, 2-blade

ECO II 3520 Brushless Motor 560KV - GF14 x 7, 2-blade
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
25.01	2.4	610	59.9	10.18	3609	30%
24.98	5.2	1130	129.4	8.73	4755	40%
24.94	9.5	1720	236.5	7.27	5827	50%
24.89	15.5	2390	386.7	6.18	6839	60%
24.82	23.3	3100	577.2	5.37	7737	70%
24.73	33.4	3910	826.3	4.73	8626	80%
24.62	46.1	4720	1135.7	4.16	9449	90%
24.47	62.9	5610	1540.1	3.64	10192	Max

770KV

GF12 x 6, 2-blade (4S)

ECO II 3520 Brushless Motor 770KV - GF12 x 6, 2-blade (4S)
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
16.84	2.2	320	36.5	8.76	3432	30%
16.82	4.2	580	70.6	8.22	4477	40%
16.79	7.3	910	122.6	7.42	5509	50%
16.75	11.8	1300	197.1	6.59	6555	60%
16.7	17.4	1700	291.2	5.84	7486	70%
16.63	24.6	2160	409.9	5.27	8408	80%
16.55	33.9	2680	560.8	4.78	9285	90%
16.45	44.8	3200	736.5	4.34	10149	Max

GF13 x 6.5, 2-blade (4S)

ECO II 3520 Brushless Motor 770KV - GF13 x 6.5, 2-blade (4S)
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
16.83	2.6	430	44.5	9.67	3313	30%
16.81	5.4	780	91.2	8.56	4357	40%
16.77	9.7	1190	162	7.34	5337	50%
16.71	15.6	1680	260.3	6.45	6298	60%
16.64	23.1	2170	385	5.64	7151	70%
16.56	32.3	2690	534.9	5.03	7975	80%
16.46	44.4	3310	731.3	4.53	8761	90%
16.34	58.5	3920	956.4	4.1	9516	Max

GF14 x 7, 2-blade (4S)

ECO II 3520 Brushless Motor 770KV - GF14 x 7, 2-blade (4S)
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
16.83	2.9	470	49	9.59	3282	30%
16.8	6.1	870	102.3	8.5	4299	40%
16.76	10.8	1350	181.7	7.43	5254	50%
16.7	17.5	1890	291.8	6.48	6170	60%
16.62	26	2450	432.8	5.66	6986	70%
16.53	36.6	3060	604.7	5.06	7747	80%
16.41	50.3	3760	825	4.56	8459	90%
16.28	65.9	4380	1072.8	4.08	9161	Max

GF12 x 6, 2-blade (5S)

ECO II 3520 Brushless Motor 770KV - GF12 x 6, 2-blade (5S)
VoltageV	CurrentA	Thrustg	PowerW	Efficiencyg/W	SpeedRPM	Throttle%
21.01	3	500	62.2	8.04	4216	30%
20.98	5.9	890	124.6	7.14	5512	40%
20.94	10.6	1390	221.7	6.27	6791	50%
20.88	16.9	1920	352.5	5.45	7931	60%
20.8	25.2	2550	525	4.86	9068	70%
20.71	35.7	3170	739.6	4.29	10135	80%
20.59	49.4	3890	1017.2	3.82	11072	90%
20.46	65.7	4560	1343.8	3.39	11990	Max

APPLICATIONS

Recommended use

large FPVlarge fixed-wing RC aircraft12-15 inch propeller platformshigh-efficiency aerial propulsionengineering and custom aircraft projectsspecialty builds