Cobra C2213/12 Motor Propeller Data
Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (3S)
12-Turn Delta 2000 RPM/Volt Io = 1.20 Amps @ 8v Rm = 0.040 Ohms 30 Amps 330 W 
 
Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
27.7 mm,  1.09 in. 28.0 mm,  1.10 in. 42.0 mm,  1.65 in. 3.17 mm,  0.125 in. 60.0 gm,   2.11 oz
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 7x4-E 7.4 14.86 110.0 12,060 45.7 586 20.67 5.33
APC 7x5-E 7.4 18.51 137.0 11,460 54.3 591 20.85 4.31
APC 7x6-E 7.4 19.43 143.8 11,310 64.3 636 22.43 4.42
APC 8x4-E 7.4 21.21 157.0 11,030 41.8 782 27.58 4.98
APC 8x6-E 7.4 28.57 211.4 9,780 55.6 820 28.92 3.88
APC 9x4.5-E 7.4 27.58 204.1 9,920 42.3 995 35.10 4.88
APC 9x6-E 7.4 30.58 226.3 9,480 53.9 949 33.47 4.19
GWS 7x3.5-DD 7.4 9.13 67.6 13,030 43.2 438 15.45 6.48
GWS 7x3.5x3-DD 7.4 11.55 85.5 12,620 41.8 502 17.71 5.87
GWS 8x4-DD 7.4 17.01 125.9 11,730 44.4 730 25.75 5.80
GWS 8x4x3-DD 7.4 20.54 152.0 11,170 42.3 802 28.29 5.28
GWS 9x5-DD 7.4 26.95 199.4 10,100 47.8 1010 35.63 5.06
GWS 9x5x3-DD 7.4 31.99 236.7 9,280 43.9 1041 36.72 4.40
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 5x5-E 11.1 14.17 157.3 18,910 89.5 359 12.66 2.28
APC 5.25x4.75-E 11.1 15.97 177.3 18,550 83.4 507 17.88 2.86
APC 5.5x4.5-E 11.1 16.59 184.1 18,420 78.5 519 18.31 2.82
APC 6x4-E 11.1 18.48 205.1 18,060 68.4 697 24.59 3.40
APC 6x5.5-E 11.1 23.03 255.6 17,170 89.4 658 23.21 2.57
APC 7x4-E 11.1 28.18 312.8 16,170 61.3 1135 40.04 3.63
APC 7x5-E 11.1 33.31 369.7 15,100 71.5 1063 37.50 2.87
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 4.1x4.1-E 14.8 11.72 173.5 26,430 106.4 395 13.93 2.28
APC 4.7x4.25-E 14.8 17.85 264.2 24,900 100.2 560 19.75 2.12
APC 4.75x4.75-E 14.8 19.94 295.1 24,460 110.0 552 19.47 1.87
APC 4.75x5.5-E 14.8 21.89 324.0 23,970 124.8 517 18.24 1.60
APC 5x5-E 14.8 22.42 331.8 23,830 112.8 581 20.49 1.75
APC 5.25x4.75-E 14.8 25.58 378.6 23,120 104.0 788 27.80 2.08
APC 5.5x4.5-E 14.8 26.08 386.0 22,990 98.0 818 28.85 2.12
APC 6x4-E 14.8 29.14 431.2 22,300 84.5 1084 38.24 2.51
APC 6x5.5-E 14.8 34.63 512.5 20,970 109.2 985 34.74 1.92
                   
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.  The test voltages used are based on a properly sized Li-Po battery for the current
draw of the motor being tested.  If you are using a larger than normal capacity battery, or a very
high C-Rated battery, your actual voltages will be higher than those shown in this chart, and this
will result in higer current draw for each prop used.  You should always test your power system
with a watt meter whenever a prop is used to ensure that you are not exceeding the recommended
rating of the motor being used.  The prop recommendations in this chart are based on the motor
receiving adequate cooling throughout its operation.  If your motor is being used inside a cowl, you
must provide adequate cooling to the motor and make sure that the motor is not getting too hot
during operation.