Motor Question

[xtopher]

I bought that long ago(1 year or more maybe) 'cause I had a good deal.This year I got a balsa trainer and converted it to electric. It's faster than my F-16 jet; flies like a rocket on a 13X6 prop and 6s 4000, 35C on a 100A esc
and the motor is not even warm at full throttle during 6 mins!
If I put a 15'' prop, I could extend my flight time twice - I am satisfied with it.

it's 345g but it perfectly balanced the plane on CG!

the motor:
http://www.leetshop.com/Product/TURBOJET-N5055-KV400-Brushless-Outrunner-Airplane-MotorN5055400.htm

(I did not buy from them- this listing is very expensive) but it's the same item if you want to have a look at

I believe it's too much but I like 'more power' than 'not or just enough'

I read about it - I could not find the pull, for the same model BUT 1300W = 3700 g 3D, or sport 5800g

I remember I bought it for it's 7500g pull (sport)!

it's a 2200 W and it's amazingly powerful.

My question is how far could it be pushed; what's the limit of it? - does not mean I will.

Just for knowledge

and for guys who fly 3D planes- 30cc and 50cc, what would be the raw flying weight of a 30 and 50? (roughly)

What would be the power required exactly/ how many watt and/or voltage?

Just asking to know the equivalent in terms of a gas plane

Thank you

[RichR]

Well, in terms of the motor whose link you've posted, the maximum output listed on it's spec is 2200 watts which means a max of 115 amps on 5s lipo and 85 amps on 6s lipo.

As you know, I'm assuming, prop diameter and pitch will determine amp draw. The only sure method to verify your current draw for any given setup is to use a wattmeter, that way you can approach the limit without overheating the motor. With that being said, many manufacturers will underrate the limit of their motors, in such a scenario, you'd test fly the motor briefly, land and verify it's temps. Keep in mind, that not all motors are made equal, some use very high spec'd materials and others do not. By running a motor 'hot', you may potentially slowly demagnetize the magnets or scorch the enamel off of the windings leading to a short-circuit. :o

[Sempai-mj]

Hey Rich,
How are you?

[RichR]

"and for guys who fly 3D planes- 30cc and 50cc, what would be the raw flying weight of a 30 and 50? (roughly)

What would be the power required exactly/ how many watt and/or voltage?

Just asking to know the equivalent in terms of a gas plane

Thank you"



To answer this portion of your question, 1 horsepower is equivalent to roughly 745 watts. Using this conversion, you can transition from a gas engine to an electric motor, all the meanwhile producing said power with the correct propeller size. Firstly, your electric motor must be in the correct weight range (meaning in proximity to gas engine weight, generally speaking, they are lighter so ballast is needed to correct for CG), secondly it must be of the equivalent kV to swing the same size prop as the gasser, and thirdly it is able to produce a sufficient amount of total watts with said prop to equal the horsepower of the gas engine.


Example, let's use a 30cc that produces 3.8 horsepower!

3.8 x 745= 2831 watts

So we know we need to make around 2800 watts of power while swinging an 18x10, a kV of around 250 to 300 will be able to swing a 18x10 prop on 9s or 10s and achieve comparable power to the 30cc gas engine.

[RichR]

Hey Rich,
How are you?

Hi Mike,

I'm good thanks, just building away on these long, dark winter nights in preparation for the spring. My thumbs freeze attempting to fly in winter!
You still flying the Blizzard?

[Sempai-mj]

Oh The blizzard, need a conversation about that one. Pm me your tele #

[xtopher]

Thank you so much rich!!!!

[xtopher]

Again Rich, thank you very much...for taking so much time to reply to my questions

All the best