Cobra C-4120-20 480Kv Motor Propeller Data
	Magnets	Motor Wind		Motor Kv		No-Load Current		Motor Resistance		I Max	P Max (8S)
	14-Pole	20-Turn Delta		480 RPM/Volt		Io = 2.50 Amps @ 20v		Rm =  0.036 Ohms		48 Amps	1420 W
	Stator	Outside Diameter		Body Length		Total Shaft Length		Shaft Diameter		Motor Weight
	12-Slot	49.8 mm,  1.96 in.		50.3 mm, 1.98 in.		74.2 mm,  2.92 in.		6.00 mm,  0.236 in.		290 grams, 10.23 oz.
	Test Data From		Input	16.0 V	20.0 V	24.0V	28.0V	Measured Kv value		Measured Rm Value
	Sample Motor		Io Value	1.452 A	1.662 A	1.891 A	2.094 A	449 RPM/Volt @ 20V		0.0362 Ohms
	Prop	Prop	Li-Po	Input	Motor	Input	Prop	Pitch Speed	Thrust	Thrust	Thrust Eff.
	Manf.	Size	Cells	Voltage	Amps	Watts	RPM	in MPH	Grams	Ounces	Grams/W
	APC	11x10-E	5	18.5	20.11	372.1	7,538	71.4	1,386	48.89	3.72
	APC	12x8-E	5	18.5	19.75	365.4	7,555	57.2	1,704	60.11	4.66
	APC	12x10-E	5	18.5	24.80	458.7	7,367	69.8	1,817	64.09	3.96
	APC	12x12-E	5	18.5	29.04	537.2	7,225	82.1	1,702	60.04	3.17
	APC	13x6.5-E	5	18.5	21.10	390.3	7,364	45.3	2,203	77.71	5.64
	APC	13x8-E	5	18.5	23.43	433.4	7,265	55.0	2,235	78.84	5.16
	APC	13x10-E	5	18.5	31.39	580.7	6,991	66.2	2,167	76.44	3.73
	APC	14x7-E	5	18.5	28.04	518.6	7,257	48.1	2,729	96.26	5.26
	APC	14x8.5-E	5	18.5	29.04	537.3	7,087	57.0	2,725	96.12	5.07
	APC	14x10-E	5	18.5	30.31	560.6	7,188	68.1	2,774	97.85	4.95
	APC	14x12-E	5	18.5	44.91	830.8	6,712	76.3	2,429	85.68	2.92
	APC	15x4-E	5	18.5	21.94	405.9	7,481	28.3	2,609	92.03	6.43
	APC	15x6-E	5	18.5	29.71	549.6	7,213	41.0	3,111	109.74	5.66
	APC	15x8-E	5	18.5	32.72	605.3	7,108	53.8	3,121	110.09	5.16
	APC	15x10-E	5	18.5	46.06	852.1	6,670	63.2	3,363	118.63	3.95
	APC	16x8-E	5	18.5	46.31	856.8	6,506	49.3	3,845	135.63	4.49
	APC	16x10-E	5	18.5	53.58	991.2	6,395	60.6	3,951	139.37	3.99
	APC	17x8-E	5	18.5	52.43	969.9	6,407	48.5	4,320	152.38	4.45
	MAS	12x8x3	5	18.5	25.42	470.3	7,356	55.7	2,433	85.82	5.17
	MAS	13x8x3	5	18.5	27.27	504.5	7,138	54.1	2,638	93.05	5.23
	MAS	14x7x3	5	18.5	33.68	623.2	7,074	46.9	3,233	114.04	5.19
	MAS	14x9x3	5	18.5	40.52	749.6	6,846	58.3	3,624	127.83	4.83
	MAS	15x7x3	5	18.5	41.91	775.4	6,797	45.1	3,836	135.31	4.95
	MAS	16x8x3	5	18.5	46.85	866.7	6,473	49.0	4,223	148.96	4.87
	Prop	Prop	Li-Po	Input	Motor	Input	Prop	Pitch Speed	Thrust	Thrust	Thrust Eff.
	Manf.	Size	Cells	Voltage	Amps	Watts	RPM	in MPH	Grams	Ounces	Grams/W
	APC	11x7-E	6	22.2	19.51	433.1	9,107	60.4	2,046	72.17	4.72
	APC	11x8-E	6	22.2	21.98	488.0	8,995	68.1	1,954	68.92	4.00
	APC	11x8.5-E	6	22.2	24.01	533.0	8,914	71.8	2,059	72.63	3.86
	APC	11x10-E	6	22.2	27.70	614.9	8,782	83.2	1,932	68.15	3.14
	APC	12x6-E	6	22.2	20.67	458.9	8,883	50.5	2,377	83.85	5.18
	APC	12x8-E	6	22.2	27.47	609.9	8,787	66.6	2,362	83.32	3.87
	APC	12x10-E	6	22.2	34.40	763.7	8,523	80.7	2,466	86.98	3.23
	APC	12x12-E	6	22.2	37.06	822.8	8,226	93.5	2,229	78.62	2.71
	APC	13x4-E	6	22.2	18.58	412.5	9,136	34.6	2,421	85.40	5.87
	APC	13x6.5-E	6	22.2	30.79	683.5	8,656	53.3	3,117	109.95	4.56
	APC	13x8-E	6	22.2	34.40	763.6	8,542	64.7	3,147	111.01	4.12
	APC	13x10-E	6	22.2	46.13	1024.0	8,146	77.1	2,965	104.59	2.90
	APC	14x7-E	6	22.2	39.57	878.4	8,358	55.4	3,723	131.32	4.24
	APC	14x8.5-E	6	22.2	42.08	934.1	8,274	66.6	3,758	132.56	4.02
	APC	14x10-E	6	22.2	42.32	939.6	8,265	78.3	3,667	129.35	3.90
	APC	15x4-E	6	22.2	30.70	681.6	8,649	32.8	3,657	129.00	5.37
	APC	15x6-E	6	22.2	41.84	928.9	8,290	47.1	4,251	149.95	4.58
	APC	15x8-E	6	22.2	45.26	1004.7	8,156	61.8	4,196	148.01	4.18
	MAS	11x8x3	6	22.2	22.33	495.7	8,820	66.8	2,230	78.66	4.50
	MAS	12x6x3	6	22.2	23.84	529.3	8,929	50.7	2,608	91.99	4.93
	MAS	12x8x3	6	22.2	34.09	756.8	8,546	64.7	3,337	117.71	4.41
	MAS	13x8x3	6	22.2	37.99	843.4	8,416	63.8	3,726	131.43	4.42
	MAS	14x7x3	6	22.2	44.84	995.4	8,179	54.2	4,385	154.67	4.41
	MAS	14x9x3	6	22.2	53.85	1195.5	7,878	67.1	4,846	170.94	4.05
	MAS	15x7x3	6	22.2	53.26	1182.4	7,702	51.1	4,952	174.67	4.19
	Prop	Prop	Li-Po	Input	Motor	Input	Prop	Pitch Speed	Thrust	Thrust	Thrust Eff.
	Manf.	Size	Cells	Voltage	Amps	Watts	RPM	in MPH	Grams	Ounces	Grams/W
	APC	11x5.5-E	7	25.9	19.98	517.4	10,403	54.2	2,379	83.92	4.60
	APC	11x7-E	7	25.9	26.00	673.5	10,361	68.7	2,684	94.67	3.99
	APC	11x8-E	7	25.9	29.41	761.6	10,223	77.4	2,556	90.16	3.36
	APC	11x8.5-E	7	25.9	31.99	828.6	10,136	81.6	2,665	94.00	3.22
	APC	11x10-E	7	25.9	36.09	934.8	9,958	94.3	2,466	86.98	2.64
	APC	12x6-E	7	25.9	29.24	757.2	10,230	58.1	3,265	115.17	4.31
	APC	12x8-E	7	25.9	36.97	957.6	9,938	75.3	3,084	108.78	3.22
	APC	12x10-E	7	25.9	43.17	1118.2	9,521	90.2	3,033	106.98	2.71
	APC	12x12-E	7	25.9	49.59	1284.4	9,468	107.6	2,935	103.53	2.29
	APC	13x4-E	7	25.9	24.58	636.5	10,418	39.5	3,212	113.30	5.05
	APC	13x6.5-E	7	25.9	39.95	1034.7	9,638	59.3	3,898	137.50	3.77
	APC	13x8-E	7	25.9	45.70	1183.7	9,615	72.8	4,014	141.59	3.39
	APC	14x7-E	7	25.9	53.76	1392.5	9,316	61.8	4,671	164.76	3.35
	APC	15x4-E	7	25.9	39.44	1021.6	9,633	36.5	4,690	165.43	4.59
	MAS	11x7x3	7	25.9	25.84	669.2	10,155	67.3	2,843	100.28	4.25
	MAS	11x8x3	7	25.9	29.80	771.7	10,202	77.3	2,983	105.22	3.87
	MAS	12x6x3	7	25.9	29.22	756.9	10,024	57.0	3,292	116.12	4.35
	MAS	12x8x3	7	25.9	43.57	1128.5	9,689	73.4	4,316	152.24	3.82
	MAS	13x8x3	7	25.9	48.53	1256.9	9,489	71.9	4,761	167.94	3.79
	Prop	Prop	Li-Po	Input	Motor	Input	Prop	Pitch Speed	Thrust	Thrust	Thrust Eff.
	Manf.	Size	Cells	Voltage	Amps	Watts	RPM	in MPH	Grams	Ounces	Grams/W
	APC	11x5.5-E	8	29.6	27.82	823.4	11,841	61.7	3,192	112.59	3.88
	APC	11x7-E	8	29.6	34.31	1015.5	11,547	76.5	3,346	118.03	3.29
	APC	11x8-E	8	29.6	38.23	1131.6	11,404	86.4	3,193	112.63	2.82
	APC	11x8.5-E	8	29.6	41.23	1220.4	11,265	90.7	3,302	116.47	2.71
	APC	11x10-E	8	29.6	46.29	1370.1	11,043	104.6	3,064	108.08	2.24
	APC	12x6-E	8	29.6	38.86	1150.2	11,375	64.6	4,113	145.08	3.58
	APC	12x8-E	8	29.6	47.34	1401.3	11,029	83.6	3,808	134.32	2.72
	APC	13x4-E	8	29.6	31.87	943.4	11,661	44.2	4,146	146.24	4.39
	APC	13x6.5-E	8	29.6	53.56	1585.3	10,572	65.1	4,714	166.28	2.97
	MAS	11x7x3	8	29.6	33.80	1000.5	11,582	76.8	3,692	130.23	3.69
	MAS	11x8x3	8	29.6	35.74	1058.0	11,252	85.2	3,632	128.11	3.43
	MAS	12x6x3	8	29.6	38.43	1137.6	11,398	64.8	4,299	151.64	3.78
	© 2017 Innov8tive Designs, Inc.
	This chart, and the data contained within it, are the property of Innov8tive Designs, Inc., and may not be reproduced without permission from the author.
	Propeller Chart Color Code Explanation
		The prop is to small to get good performance from the motor. (Less than 50% power)
		The prop is sized right to get good power from the motor. (50 to 80% power)
		The prop can be used, but full throttle should be kept to short bursts. (80 to 100% power)
		The prop is too big for the motor and should not be used. (Over 100% power)
	PLEASE NOTE:
	The Data contained in this Prop Chart is based on actual measurements, taken in a controlled test environment, at an altitude of
	584 feet above sea level.  The test voltages used are based on the standard output of a Li-Po battery under load, which is 3.70 volts
	per cell.  If you are using a battery that is larger in capacity than normal, or has a very high C-rating, then your actual voltages will
	be higher than those shown in the chart, and this will result in a higher current and power value for every prop used.  You should
	always test your actual power system with a watt meter before flying your model to make sure that you are not exceeding the
	recommended current and power ratings of the motor being used.  The prop recommendations in this chart assume that the motor
	receives adequate cooling throughout its operation.  If your motor is being used inside a cowl or fuselage, you must ensure that
	the motor receives sufficient airflow, and does not get too hot during operation.  It is always best to use a prop size that pulls no
	more than 80% of the motors maximum recommended current value to ensure safe operation under all conditions.