Cobra C2217/12 Motor Propeller Data
Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (3S)
12-Turn Delta 1550 RPM/Volt Io = 1.15 Amps @ 8v Rm = 0.044 Ohms 32 Amps 350 W 
 
Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
27.7 mm,  1.09 in. 33.0 mm,  1.30 in. 47.0 mm,  1.85 in. 3.17 mm,  0.125 in. 74.0 gm,   2.61 oz
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 8x3.8-SF 7.4 14.14 104.6 9,120 32.8 655 23.10 6.26
APC 8x4-E 7.4 12.14 89.8 9,400 35.6 559 19.72 6.22
APC 8x6-E 7.4 17.37 128.5 8,670 49.3 639 22.54 4.97
APC 8x6-SF 7.4 21.84 161.6 8,040 45.7 685 24.16 4.24
APC 9x3.8-SF 7.4 18.32 135.6 8,537 30.7 817 28.82 6.03
APC 9x4.5-E 7.4 16.65 123.2 8,770 37.4 765 26.98 6.21
APC 9x4.7-SF 7.4 17.91 132.5 8,610 38.3 808 28.50 6.10
APC 9x6-E 7.4 19.17 141.9 8,460 48.1 774 27.30 5.46
APC 9x6-SF 7.4 27.90 206.5 7,146 40.6 850 29.98 4.12
APC 9x7.5-E 7.4 25.18 186.3 7,570 53.8 751 26.49 4.03
APC 9x7.5-SF 7.4 30.77 227.7 6,660 47.3 634 22.36 2.78
APC 10x3.8-SF 7.4 25.86 191.4 7,430 26.7 1007 35.52 5.26
APC 10x4.7-SF 7.4 27.40 202.8 7,270 32.4 1026 36.19 5.06
APC 10x5-E 7.4 22.04 163.1 8,020 38.0 905 31.92 5.55
APC 10x6-E 7.4 23.42 173.3 7,800 44.3 946 33.37 5.46
APC 10x7-E 7.4 26.15 193.5 7,420 49.2 954 33.65 4.93
APC 10x7-SF 7.4 33.55 248.3 6,320 41.9 984 34.71 3.96
APC 11x3.8-SF 7.4 27.85 206.1 7,130 25.7 1100 38.80 5.34
APC 11x4.7-SF 7.4 31.46 232.8 6,580 29.3 1151 40.60 4.94
APC 11x5.5-E 7.4 27.57 204.0 7,280 37.9 1106 39.01 5.42
APC 11x7-E 7.4 30.49 225.6 6,770 44.9 1085 38.27 4.81
GWS 8x4-DD 7.4 9.58 70.9 9,760 37.0 499 17.60 7.04
GWS 9x5-DD 7.4 16.21 120.0 8,830 41.8 771 27.20 6.43
GWS 9x5x3-DD 7.4 20.08 148.6 8,320 39.4 856 30.19 5.76
GWS 10x6-DD 7.4 20.94 155.0 8,160 46.4 904 31.89 5.83
GWS 10x6x3-DD 7.4 25.74 190.5 7,480 42.5 1029 36.30 5.40
GWS 10x8-HD 7.4 29.68 219.6 6,830 38.8 834 29.42 3.80
GWS 11x7-DD 7.4 28.15 208.3 7,040 46.7 1103 38.91 5.29
GWS 12x6-HD 7.4 29.69 219.7 6,770 38.5 1165 41.09 5.30
 
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 11.1 15.95 177.0 13,990 53.0 824 29.07 4.65
APC 7x5-E 11.1 20.14 223.6 13,350 63.2 829 29.24 3.71
APC 7x6-E 11.1 20.88 231.8 13,210 75.1 890 31.39 3.84
APC 8x4-E 11.1 22.92 254.4 12,860 48.7 1088 38.38 4.28
APC 8x6-E 11.1 31.72 352.1 11,440 65.0 1167 41.16 3.31
APC 9x4.5-E 11.1 29.99 332.9 11,630 49.6 1403 49.49 4.21
 
Prop Prop Input Motor Watts Prop Pitch Thrust  Thrust Thrust Eff.
Manf. Size Voltage Amps Input RPM Speed Grams Ounces Grams/W
APC 5.5x4.5-E 14.8 14.99 221.9 19,470 83.0 590 20.81 2.66
APC 6x4-E 14.8 16.87 249.7 19,130 72.5 791 27.90 3.17
APC 6x5.5-E 14.8 21.09 312.1 18,140 94.5 739 26.07 2.37
APC 7x4-E 14.8 25.82 382.1 17,234 65.3 1304 46.00 3.41
APC 7x5-E 14.8 31.20 461.8 16,200 76.7 1253 44.20 2.71
                   
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.