Cobra CM-2213/12 Motor Propeller Data
Magnets Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (4S)
14-Pole 12-Turn Delta 2000 RPM/Volt Io = 1.29 Amps @ 10v Rm = 0.040 Ohms 30 Amps 440 W
 
Stator Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
12-Slot 27.0 mm,  1.063 in. 28.0 mm,  1.102 in. 30.1 mm,  1.185 in. 3.17 mm,  0.125 in. 68.6 gm,   2.42 oz
 
Test Data From Input 6.0 V 8.0 V 10.0V 12.0V Measured Kv value Measured Rm Value
Sample Motor Io Value 0.95 A 1.09 A 1.29 A 1.44 A 1995 RPM/Volt @ 10v 0.040 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 5.25x4.75-E 3 11.1 16.22 180.0 18,857 84.8 510 17.99 2.83
APC 5.4x4.5-E 3 11.1 16.81 186.6 18,579 79.2 536 18.91 2.87
APC 6x4-E 3 11.1 18.10 200.9 18,506 70.1 767 27.05 3.82
APC 7x4-SF 3 11.1 31.64 351.2 15,919 60.3 1128 39.79 3.21
APC 7x5-E 3 11.1 34.84 386.7 15,338 72.6 1103 38.91 2.85
HQ 5x4 3 11.1 9.28 103.0 20,288 76.8 446 15.73 4.33
HQ 5x4x3 3 11.1 12.82 142.3 19,547 74.0 580 20.46 4.08
HQ 5x4.5-BN 3 11.1 15.93 176.8 18,924 80.6 648 22.86 3.66
HQ 6x3 3 11.1 10.05 111.6 20,123 57.2 522 18.41 4.68
HQ 6x4.5 3 11.1 19.21 213.2 18,299 78.0 870 30.69 4.08
HQ 6x4.5-BN 3 11.1 25.62 284.4 17,803 75.9 985 34.74 3.46
HQ 6x4.5x3 3 11.1 24.65 273.6 17,253 73.5 1032 36.40 3.77
HQ 7x4.5 3 11.1 29.88 331.7 16,292 69.4 1200 42.33 3.62
 
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 5.25x4.75-E 4 14.8 25.63 379.3 23,443 105.4 799 28.18 2.11
APC 5.5x4.5-E 4 14.8 26.36 390.1 23,388 99.7 843 29.74 2.16
APC 6x4-E 4 14.8 29.27 433.2 22,830 86.5 1148 40.49 2.65
HQ 4x4.5-BN 4 14.8 13.02 192.7 25,472 108.5 560 19.75 2.91
HQ 5x3 4 14.8 8.05 119.1 27,490 78.1 477 16.83 4.00
HQ 5x4 4 14.8 12.50 185.0 25,757 97.6 649 22.89 3.51
HQ 5x4x3 4 14.8 17.30 256.0 24,607 93.2 901 31.78 3.52
HQ 5x4.5-BN 4 14.8 24.03 355.6 23,618 100.6 1033 36.44 2.90
HQ 6x3 4 14.8 12.91 191.1 25,536 72.5 791 27.90 4.14
HQ 6x4.5 4 14.8 28.97 428.8 22,884 97.5 1372 48.40 3.20
HQ 6x4.5-BN 4 14.8 38.13 564.3 21,238 90.5 1515 53.44 2.68
HQ 6x4.5x3 4 14.8 36.91 546.3 21,538 91.8 1599 56.40 2.93
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.