liversalts

This plane is using the 90" cub wing from a Great Planes kit.

The following is from Motorcalc (I hope it is reasonable):

MotOpinion - Cubster 14x10
100ft above Sea Level, 30.00inHg, 70°F (Florida)

Motor: Model Motors AXI AC4120/14; 650rpm/V; 2A no-load; 0.041 Ohms
Battery: Sanyo CP-2400SCR; 14 cells; 2300mAh @ 1.2V; 0.0053 Ohms/cell
Speed Control: Castle Creations Phoenix 80; 0.001 Ohms; High rate
Drive System: APC 14x8 Electric; 14x8 (Pconst=1.08; Tconst=1) direct drive
Airframe: Cubster - Camera Plane; 1132sq.in; 162.1oz; 20.6oz/sq.ft; Cd=0.081; Cl=0.72; Clopt=0.83; Clmax=1.47
Stats: 58 W/lb in; 44 W/lb out; 19mph stall; 26mph opt @ 57% (16:56, 102°F); 28mph level @ 60% (15:27, 104°F); 713ft/min @ 18.2°; -249ft/min @ -6.3°

Power System Notes:

The full-throttle motor current at the best lift-to-drag ratio airspeed (41.8A) falls between the motor's maximum efficiency current (21.4A) and its current at theoretical maximum output (115.7A), thus making effective use of the motor.
The voltage (13.6V) exceeds 12V. Be sure the speed control is rated for at least the number of cells specified above.

Aerodynamic Notes:

The static pitch speed (54mph) is within the range of approximately 2.5 to 3 times the model's stall speed (19mph), which is considered ideal for good performance.
With a wing loading of 20.6oz/sq.ft, a model of this size will have trainer-like flying characteristics. It would make an ideal trainer, for use in calm to light wind conditions.
The static thrust (91.5oz) to weight (162.1oz) ratio is 0.56:1, which will result in short take-off runs, and no difficulty taking off from grass surfaces (assuming sufficiently large wheels).
At the best lift-to-drag ratio airspeed, the excess-thrust (51.4oz) to weight (162.1oz) ratio is 0.32:1, which will give strong climbs and rapid acceleration. This model will most likely readily loop from level flight, and have sufficient in-flight thrust for many aerobatic maneuvers.

General Notes:

This analysis is based on calculations that take motor heating effects into account.


Motor Model Motors AXI AC4120/14
Motor Constant (rpm/V) 650
No Load Current (A) 2
Armature Resistance (Ohms) 0.041
Battery Sanyo CP-2400SCR
Series Cell Count 14
Parallel Cell Count 1
Cell Capacity (mAh) 2300
Pack Capacity (mAh) 2300
Cell Voltage (V) 1.2
Pack Voltage (V) 16.8
Cell Resistance (Ohms) 0.0053
Pack Resistance (Ohms) 0.0742
Speed Control (ESC) Castle Creations Phoenix 80
Resistance (Ohms) 0.001
Maximum Current (A) 80
Number of ESCs 1
Drive System APC 14x8 Electric
Gear Ratio 1.00:1
Propeller (in x in) 14x8
Series Motors 1
Parallel Motors 1
Number of Propellers 1
Blades per Propeller 2
Airframe Cubster - Camera Plane
Wing Span (in) 90
Wing Area (sq.in) 1132
Total Weight (oz) 162.1
Static Predictions
Current (A) 43.2
Motor Voltage (V) 13.6
Input Power (W) 585.1
Input Power Loading (W/lb) 57.7
Power Loss (W) 134.7
Motor/Gearbox Output (W) 450.3
Output Power Loading (W/lb) 44.5
Motor/Gearbox Efficiency (%) 77.0
Shaft Efficiency (%) 62.1
Motor RPM 7111
Propeller RPM 7111
Static Thrust (oz) 91.5
Pitch Speed (mph) 53.9
Run Time (min:sec) 3:12
Flight Predictions
Stall Speed (mph) 19
Optimal Flight Speed (mph) 26
Throttle for Optimal (%) 57
Duration at Optimal (m:s) 16:56
Motor Temp at Optimal (°F) 102
Hands-off Speed (mph) 28
Throttle for Hands-off (%) 60
Duration Hands-off (m:s) 15:27
Motor Temp Hands-off (°F) 104
Best Rate of Climb (ft/min) 713
Rate of Sink (ft/min) -249