Cobra CM-4008/24 600Kv Motor Propeller Data
Magnets Motor Wind Motor Kv No-Load Current Motor Resistance I Max P Max (4S)
22-Pole 24-Turn Wye 600 RPM/Volt Io = 0.72 Amps @ 12v Rm = 0.086 Ohms 23 Amps 340 W
 
Stator Outside Diameter Body Length Total Shaft Length Shaft Diameter Motor Weight
24-Slot 45.5 mm,  1.791 in. 23.9 mm,  0.941 in. 33.5 mm,  1.319 in. 4.00 mm,  0.157 in. 106 gm,   3.74 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 0.65 A 0.72 A .79 A .87 A 597 RPM/Volt @ 12V 0.086 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 12x4.5-MR 3 11.1 9.38 104.1 5,737 29.9 880 31.04 8.45
APC 13x5.5-MR 3 11.1 12.36 137.2 5,423 28.2 1103 38.91 8.04
APC 14x5.5-MR 3 11.1 15.11 167.7 5,231 27.2 1306 46.07 7.79
APC 16x5.5-MR 3 11.1 21.17 235.0 4,705 24.5 1673 59.01 7.12
GemFan 13x4.5-MR-W 3 11.1 10.99 122.0 5,597 23.9 981 34.60 8.04
GemFan 14x4.5-MR-W 3 11.1 12.90 143.2 5,424 23.1 1155 40.74 8.07
GemFan 15x4.5-MR-W 3 11.1 13.98 155.2 5,325 22.7 1213 42.79 7.82
GemFan 16x4.5-MR-W 3 11.1 18.31 203.2 4,939 21.0 1494 52.70 7.35
RC-Timer 12x5.5-CF 3 11.1 11.14 123.7 5,571 29.0 903 31.85 7.30
RC-Timer 13x5.5-CF 3 11.1 14.33 159.1 5,285 27.5 1100 38.80 6.92
RC-Timer 14x5.5-CF 3 11.1 19.16 212.7 4,879 25.4 1302 45.93 6.12
RC-Timer 15x5.5-CF 3 11.1 24.44 271.3 4,412 23.0 1475 52.03 5.44
 
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 10x4.5-MR 4 14.8 9.24 136.8 7,809 33.3 919 32.42 6.72
APC 11x4.5-MR 4 14.8 11.65 172.4 7,566 32.2 1167 41.16 6.77
APC 12x4.5-MR 4 14.8 14.97 221.6 7,267 31.0 1433 50.55 6.47
APC 13x5.5-MR 4 14.8 19.77 292.6 6,743 35.1 1787 63.03 6.11
APC 14x5.5-MR 4 14.8 23.53 348.2 6,420 33.4 2009 70.86 5.77
GemFan 11x4-MR-W 4 14.8 10.32 152.7 7,715 29.2 1055 37.21 6.91
GemFan 12x4-MR-W 4 14.8 13.73 203.2 7,361 27.9 1341 47.30 6.60
GemFan 13x4.5-MR-W 4 14.8 17.08 252.8 7,049 30.0 1601 56.47 6.33
GemFan 14x4.5-MR-W 4 14.8 20.02 296.3 6,776 28.9 1844 65.04 6.22
GemFan 15x4.5-MR-W 4 14.8 21.72 321.5 6,585 28.1 1899 66.98 5.91
GemFan 16x4.5-MR-W 4 14.8 27.89 412.8 5,987 25.5 2208 77.88 5.35
RC-Timer 10x5.5-CF 4 14.8 7.94 117.5 7,956 41.4 781 27.55 6.65
RC-Timer 11x5.5-CF 4 14.8 11.89 176.0 7,556 39.4 1079 38.06 6.13
RC-Timer 12x5.5-CF 4 14.8 18.09 267.7 6,948 36.2 1472 51.92 5.50
RC-Timer 13x5.5-CF 4 14.8 23.55 348.5 6,481 33.8 1744 61.52 5.00
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.