Cobra CM-2814/36 470Kv Motor Propeller Data
Magnets Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (6S)
14-Pole 36-Turn Delta 470 RPM/Volt Io = 0.29 Amps @ 12v Rm = 0.188 Ohms 17 Amps 375 W
 
Stator Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
12-Slot 35.0 mm,  1.378 in. 40.4 mm,  1.591 in. 46.6 mm,  1.835 in. 5.00 mm,  0.197 in. 117 gm,   4.13 oz
 
Test Data From Input 10.0 V 12.0 V 14.0V 16.0V Measured Kv value Measured Rm Value
Sample Motor Io Value 0.27 A 0.29 A 0.31 A 0.33 A 452 RPM/Volt @ 12V 0.188 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 12x4.5-MR 4 14.8 6.82 100.9 5,742 24.5 876 30.90 8.68
APC 13x5.5-MR 4 14.8 8.96 132.6 5,463 28.5 1082 38.17 8.16
APC 14x5.5-MR 4 14.8 10.78 159.5 5,180 27.0 1273 44.90 7.98
APC 16x5.5-MR 4 14.8 14.85 219.8 4,639 24.2 1613 56.90 7.34
APC 18x5.5-MR 4 14.8 18.07 267.4 4,169 21.7 1868 65.89 6.98
GemFan 13x4.5-MR-W 4 14.8 8.04 119.0 5,580 23.8 991 34.96 8.33
GemFan 14x4.5-MR-W 4 14.8 9.42 139.4 5,391 23.0 1133 39.96 8.13
GemFan 15x4.5-MR-W 4 14.8 10.20 151.0 5,283 22.5 1222 43.10 8.09
GemFan 16x4.5-MR-W 4 14.8 13.15 194.6 4,860 20.7 1465 51.68 7.53
RC-Timer 12x5.5-CF 4 14.8 8.20 121.4 5,566 29.0 915 32.28 7.54
RC-Timer 13x5.5-CF 4 14.8 10.47 155.0 5,274 27.5 1094 38.59 7.06
RC-Timer 14x5.5-CF 4 14.8 13.68 202.5 4,802 25.0 1287 45.40 6.36
RC-Timer 15x5.5-CF 4 14.8 16.91 250.3 4,310 22.4 1436 50.65 5.74
 
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 11x4.5-MR 5 18.5 7.73 143.0 7,175 30.6 1051 37.07 7.35
APC 12x4.5-MR 5 18.5 9.92 183.5 6,864 29.3 1308 46.14 7.13
APC 13x5.5-MR 5 18.5 12.68 234.6 6,467 33.7 1553 54.78 6.62
APC 14x5.5-MR 5 18.5 15.19 281.0 6,078 31.7 1798 63.42 6.40
APC 16x5.5-MR 5 18.5 19.87 367.6 5,302 27.6 2148 75.77 5.84
GemFan 11x4-MR-W 5 18.5 6.87 127.1 7,302 27.7 954 33.65 7.51
GemFan 12x4-MR-W 5 18.5 9.06 167.6 6,974 26.4 1191 42.01 7.11
GemFan 13x4.5-MR-W 5 18.5 11.23 207.8 6,672 28.4 1419 50.05 6.83
GemFan 14x4.5-MR-W 5 18.5 13.08 242.0 6,372 27.2 1632 57.57 6.74
GemFan 15x4.5-MR-W 5 18.5 14.15 261.8 6,236 26.6 1712 60.39 6.54
GemFan 16x4.5-MR-W 5 18.5 17.70 327.5 5,649 24.1 2008 70.83 6.13
RC-Timer 11x5.5-CF 5 18.5 7.84 145.0 7,164 37.3 980 34.57 6.76
RC-Timer 12x5.5-CF 5 18.5 11.84 219.0 6,597 34.4 1332 46.98 6.08
RC-Timer 13x5.5-CF 5 18.5 14.96 276.8 6,144 32.0 1567 55.27 5.66
RC-Timer 14x5.5-CF 5 18.5 18.73 346.5 5,500 28.6 1725 60.85 4.98
 
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 10x4.5-MR 6 22.2 8.41 186.7 8,652 36.9 1176 41.48 6.30
APC 11x4.5-MR 6 22.2 10.48 232.7 8,323 35.5 1432 50.51 6.16
APC 12x4.5-MR 6 22.2 13.39 297.3 7,890 33.6 1777 62.68 5.98
APC 13x5.5-MR 6 22.2 16.77 372.3 7,325 38.2 2060 72.66 5.53
APC 14x5.5-MR 6 22.2 19.60 435.1 6,873 35.8 2326 82.05 5.35
GemFan 11x4-MR-W 6 22.2 9.19 204.0 8,644 32.7 1151 40.60 5.64
GemFan 12x4-MR-W 6 22.2 12.05 267.5 8,093 30.7 1633 57.60 6.10
GemFan 13x4.5-MR-W 6 22.2 14.87 330.1 7,670 32.7 1918 67.65 5.81
GemFan 14x4.5-MR-W 6 22.2 17.15 380.7 7,271 31.0 2168 76.47 5.69
RC-Timer 10x5.5-CF 6 22.2 7.19 159.6 8,842 46.1 1010 35.63 6.33
RC-Timer 11x5.5-CF 6 22.2 10.72 238.0 8,301 43.2 1346 47.48 5.66
RC-Timer 12x5.5-CF 6 22.2 15.94 353.9 7,505 39.1 1761 62.12 4.98
RC-Timer 13x5.5-CF 6 22.2 19.46 432.0 6,853 35.7 2001 70.58 4.63
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
512 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.