Cobra CM-2814/24 700Kv Motor Propeller Data
Magnets Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (4S)
14-Pole 24-Turn Delta 700 RPM/Volt Io = 0.55 Amps @ 12v Rm = 0.095 Ohms 23 Amps 340 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. 116 gm,   4.09 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 0.50 A 0.55 A 0.60 A 0.65 A 698 RPM/Volt @ 12V 0.095 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 11x4.5-MR 3 11.1 10.27 114.0 6,648 34.6 893 31.50 7.83
APC 12x4.5-MR 3 11.1 13.06 145.0 6,345 33.0 1093 38.55 7.54
APC 13x5.5-MR 3 11.1 16.52 183.4 5,942 30.9 1294 45.64 7.06
APC 14x5.5-MR 3 11.1 19.77 219.4 5,612 29.2 1494 52.70 6.81
GemFan 11x4-MR-W 3 11.1 9.19 102.0 6,768 25.6 814 28.71 7.98
GemFan 12x4-MR-W 3 11.1 12.12 134.5 6,443 24.4 1008 35.56 7.49
GemFan 13x4.5-MR-W 3 11.1 14.91 165.5 6,140 26.2 1201 42.36 7.26
GemFan 14x4.5-MR-W 3 11.1 17.18 190.7 5,875 25.0 1340 47.27 7.03
GemFan 15x4.5-MR-W 3 11.1 18.45 204.8 5,756 24.5 1418 50.02 6.92
GemFan 16x4.5-MR-W 3 11.1 23.16 257.1 5,219 22.2 1663 58.66 6.47
RC-Timer 11x5.5-CF 3 11.1 10.35 114.9 6,636 34.6 819 28.89 7.13
RC-Timer 12x5.5-CF 3 11.1 15.38 170.7 6,100 31.8 1096 38.66 6.42
RC-Timer 13x5.5-CF 3 11.1 19.42 215.6 5,635 29.3 1308 46.14 6.07
RC-Timer 14x5.5-CF 3 11.1 24.24 269.1 5,105 26.6 1439 50.76 5.35
 
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 9x4.5-MR 4 14.8 9.90 146.5 9,147 47.6 922 32.52 6.29
APC 10x4.5-MR 4 14.8 13.29 196.7 8,746 45.6 1194 42.12 6.07
APC 11x4.5-MR 4 14.8 16.58 245.4 8,366 43.6 1466 51.71 5.97
APC 12x4.5-MR 4 14.8 20.52 303.7 7,863 33.5 1736 61.23 5.72
APC 13x5.5-MR 4 14.8 25.95 384.1 7,364 38.4 2055 72.49 5.35
GemFan 10x4-MR-W 4 14.8 13.38 198.0 8,733 33.1 1176 41.48 5.94
GemFan 11x4-MR-W 4 14.8 14.47 214.2 8,609 32.6 1333 47.02 6.22
GemFan 12x4-MR-W 4 14.8 18.83 278.7 8,095 30.7 1643 57.95 5.90
GemFan 13x4.5-MR-W 4 14.8 22.47 332.6 7,600 32.4 1853 65.36 5.57
GemFan 14x4.5-MR-W 4 14.8 25.89 383.2 7,272 31.0 2067 72.91 5.39
RC-Timer 10x5.5-CF 4 14.8 11.40 168.7 8,975 46.7 1019 35.94 6.04
RC-Timer 11x5.5-CF 4 14.8 16.91 250.3 8,337 43.4 1356 47.83 5.42
RC-Timer 12x5.5-CF 4 14.8 24.04 355.8 7,429 38.7 1703 60.07 4.79
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.