ORIGINAL: edpare
Thanks opjose! I understand what you wrote and can use the information if I want to convert from glow to electric.
My current problem, however, is finding what the manufacturer meant when he called for a ''36 electric power''.
How much horsepower is ''36 EP''?
Ed
It's hard to tell from "36 electric power".
However assume that what you read is a poor translation from Chinese or some other language.
Since most glow motors come in .32, .40, .46 sizes in that range it is unlikely that 36 refers to motor power and is most likely indicative of motor diameter.
However the actual intended motor is unknown.
So you are best off looking at the estimated weight of the plane all ready to fly ( all up weight AUW ).
Take the given weight and multiply by a factor, I use 1.3 to get a good estimate.
Assuming the manufacturer says that the plane weights 3.6lbs...
3.6 x 1.3 = 4.68lbs
Then apply the watts per pound "rules"...
e.g. to get good aerobatic performance you want approximately 130 watts per pound...
So 4.68lbs x 130watts = 608 watts
A target wattage range of 610 watts will do.
Again we use the desired battery voltage ( in this range I'll go with either 11.1v or 14.8v... )
610 / 14.8v = 42A
610 watts = .82 HP
ThrustHP says that an 11x7 prop spinning at 10400 RPM produces .82 HP.
10400 x 14.8v = 700KV
So again we have a good working configuration given the weight...
- A 620 watt+ motor 700KV motor
- An ESC capable of 42A continuous ( get at least a 50A ESC or better ) @ 14.8v
( Note remember that an ESC's AMP rating may be given at different voltages so if you need a 50A 14.8v ESC and the advertisements are primarily dealing with 11.1v you'll need to INCREASE the AMP rating accordingly... thus to get something that can handle 50A @ 14.8v you'll want to look for a 60A+ ESC given for 11.1v.... although I'm not being precise on the math on this... it's easy to work out... )
- A pack capable of 42A continuous @ 14.8v, say a 2600mAh 14.8v 20C LiPo or larger...
And a prop that puts you in the right wattage/AMP draw range.
Since the prop has such a dramatic effect on the power draw, you really always want to test your configuration out with a watt meter just to be sure you have things dialed in correctly.
A watt meter will also tell you if your pack is suitable ( e.g. if the voltage does not drop too much under load, you're fine ) and how much power your prop is pulling from your electronics.