Cobra CM-2213/26 Motor Propeller Data
Magnets Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (3S)
14-Pole 26-Turn Delta 950 RPM/Volt Io = 0.42 Amps @ 12v Rm = 0.230 Ohms 14 Amps 155 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. 65 gm,   2.29 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 0.39 A 0.42 A 0.46 A 0.50 A 967 RPM/Volt @ 10v 0.230 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 8x4.5-MR 3 11.1 7.40 82.1 8,579 36.6 541 19.08 6.59
APC 9x4.5-MR 3 11.1 9.63 106.9 7,964 33.9 692 24.41 6.47
APC 10x4.5-MR 3 11.1 11.86 131.6 7,395 31.5 826 29.14 6.27
APC 11x4.5-MR 3 11.1 13.79 153.1 6,861 29.2 943 33.26 6.16
APC 12x4.5-MR 3 11.1 16.19 179.7 6,179 26.3 1043 36.79 5.80
GemFan 8x4.5-MR 3 11.1 9.08 100.8 8,155 34.8 617 21.76 6.12
GemFan 9x4.7-MR 3 11.1 10.20 113.2 7,836 34.9 714 25.19 6.31
GemFan 10x4.5-MR 3 11.1 13.62 151.2 6,907 29.4 862 30.41 5.70
GemFan 10x4-MR-W 3 11.1 11.67 129.5 7,444 28.2 809 28.54 6.25
GemFan 11x4-MR-W 3 11.1 12.89 143.1 7,090 26.9 894 31.53 6.25
GemFan 12x4-MR-W 3 11.1 15.50 172.1 6,352 24.1 991 34.96 5.76
 
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 7x4-SF 4 14.8 7.17 106.1 11,909 45.1 593 20.92 5.59
APC 7x5-E 4 14.8 8.66 128.2 11,439 54.2 591 20.85 4.61
FC 7x4.5x3 4 14.8 10.53 155.8 10,874 46.3 791 27.90 5.08
GemFan 8x4.5-MR 4 14.8 13.52 200.1 9,934 42.3 943 33.26 4.71
 
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 6x4-E 6 22.2 8.39 186.3 17,675 67.0 678 23.92 3.64
APC 7x4-SF 6 22.2 13.53 300.4 15,619 59.2 1074 37.88 3.58
APC 7x5-E 6 22.2 15.75 349.7 15,081 71.4 1085 38.27 3.10
FC 6x4.5 6 22.2 8.33 184.9 17,513 74.6 794 28.01 4.29
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.