hagar0 escribió:jaware escribió:Aqui teneis dos fotos de mi tuneado para brushless. Como veis le he añadido una chapita de aluminio para que la hélice no roce el fuselaje.
hola, queria preguntarte que helice llevas?
yo pensaba en poner una 10*4 o asi, pero no se si tendria que subirlo demasiado,
el motor que tengo es de 750 KV y por eso tengo que usar una helice de este calibre, con 3S
es que ya tengo el conjunto variador 25A, motor brushless de 750KV marca axi y una helice de 10*(no me acuerdo)
podria funcionar o sera mucha helice y poco motor para el easy??
un saludo y gracias.
Yo llevo una hélice 8x6 con un brushless un poco más potente que el tuyo 1130kv. Pero aun no lo he volado ... con lo que el resultado empírico no lo se todavía. Miguelonete me pasó el link a motocalc y es una herramienta acojonante. Yo he configurado mi modelo, motor, variador y hélice y tiene un botón de "MotOpinion". Esa opción es definitiva. Te copio lo que dice el motocalc de tu configuración y la mía:
Configuración Hagar0 para una 10x4:
MotOpinion - EasyStar
Motor: AXI 2826/10; 870rpm/V; 1.78A no-load; 0.042 Ohms.
Battery: BP Lipo; 3 cells; 2200mAh @ 3.7V; 0.0055 Ohms/cell.
Speed Control: Great Planes Electrifly Silver Series 35; 0.01 Ohms; High rate.
Drive System: 10; 10x4 (Pconst=1.31; Tconst=0.95) direct drive.
Airframe: Multiplex Easystar; 24dm²; 1070g; 44.6g/dm²; Cd=0.047; Cl=0.54; Clopt=0.69; Clmax=1.26.
Stats: 151 W/kg in; 124 W/kg out; 7.8m/s stall; 10.6m/s opt; 12m/s level; -0.86m/s @ -4.7°; -0.87m/s @ -4.7°.
Warning:
MotoCalc was unable to determine a throttle setting for hands-off cruise or best lift-to-drag ratio airspeed, so zero airspeed and full throttle will be used instead. These results will not likely be meaningful for actual flying conditions.
Inability to determine a throttle setting for an airspeed usually means the model is not capable of reaching the required speed with the given power system, or the airfoil information has not been specified correctly.
Possible Power System Problems:
The full-throttle motor current at zero airspeed (15.1A) is lower than the motor's maximum efficiency current (21.3A). A higher current level would improve system efficiency.
The estimated steady-state still-air battery temperature at zero airspeed and full throttle (approximately 84°C) is higher than the suggested maximum temperature for this cell type (50°C). This could result in battery pack damage unless adequate cooling airflow is provided and/or run times are kept short. A lower current would also decrease the battery temperature.
Current can be decreased by using fewer cells, a smaller diameter or lower pitched propeller, a higher gear ratio, or some combination of these methods.
Current can be increased by using more cells, a larger diameter or higher pitched propeller, a lower gear ratio, or some combination of these methods.
Due to the conflicting suggestions to both increase and decrease the current, this particular combination of power system components is not ideal (but not necessarily unusable).
Possible Aerodynamic Problems:
The static pitch speed (14.7m/s) is much less than 2.5 times the stall speed (7.8m/s), which may result in reduced performance at typical flying speeds and a low maximum speed. This situation is usually acceptable for an electric sailplane.
Pitch speed can be increased by using a higher pitched and/or smaller diameter propeller, a higher cell count, or some combination of these methods.
The model's maximum level flight speed (9m/s) is less than one and a half times the stall speed (7.8m/s). With such a narrow range of flying speeds, the model will require careful piloting in order not to stall.
Maximum speed can be increased by using a higher pitched and/or smaller diameter propeller, a higher cell count, or some combination of these methods.
Stall speed can be reduced by reducing weight, increasing the wing area, or using a thicker and/or more cambered airfoil.
The diameter (10.0in) to pitch (4.0in) ratio is greater than 2:1, which will result in reduced propeller efficiency at flying speeds. An appropriate smaller diameter, higher pitched propeller would improve this.
Aerodynamic Notes:
Due to some of the potential problems listed above, this model may require an experienced pilot.
At the best lift-to-drag ratio airspeed, the excess-thrust (0g) to weight (1070g) ratio is 0:1, which will give no climb ability and no accelaration. It will likely be impossible to maintain altitude.
Si le ponemos
una hélice con un paso mayor: 10x7:
MotOpinion - EasyStar
Motor: AXI 2826/10; 870rpm/V; 1.78A no-load; 0.042 Ohms.
Battery: BP Lipo; 3 cells; 2200mAh @ 3.7V; 0.0055 Ohms/cell.
Speed Control: Great Planes Electrifly Silver Series 35; 0.01 Ohms; High rate.
Drive System: 10; 10x7 (Pconst=1.31; Tconst=0.95) direct drive.
Airframe: Multiplex Easystar; 24dm²; 1070g; 44.6g/dm²; Cd=0.047; Cl=0.54; Clopt=0.69; Clmax=1.26.
Stats: 220 W/kg in; 181 W/kg out; 7.8m/s stall; 10.6m/s opt @ 49% (52:43, 26°C); 12m/s level @ 54% (44:38, 27°C); 6.96m/s @ 41.1°; -0.87m/s @ -4.7°.
Power System Notes:
The full-throttle motor current at the best lift-to-drag ratio airspeed (22.4A) falls approximately between the motor's maximum efficiency current (21.1A) and its current at theoretical maximum output (126A), thus making effective use of the motor.
Aerodynamic Notes:
The static pitch speed (24.2m/s) is within the range of approximately 2.5 to 3 times the model's stall speed (7.8m/s), which is considered ideal for good performance.
With a wing loading of 44.6g/dm², 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 (978g) to weight (1070g) ratio is 0.91:1, which will result in very short take-off runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and steep climb-outs.
At the best lift-to-drag ratio airspeed, the excess-thrust (679g) to weight (1070g) ratio is 0.63:1, which will give steep climbs and excellent acceleration. This model should be able to do consecutive loops, and has sufficient in-flight thrust for almost any aerobatic maneuver.
Fíjate que cambia como la noche al dia, de decir que seguro que quemas el variador en 10x4 a decir con 10x7 que puedes hacer acrobacias con él.
De todos modos te recomiendo que uses los valores exactos que tengas y ya ves como cambia el paso de hélice ...
Saludos, Javier.