FT Spitfire not taking off

Started by Adel, November 09, 2020, 09:47:22 PM

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Adel

Hi,

Built a FT Spitfire from a speed built kit that is refusing to take off. Have attempted to fly it 4 times already but every time it has crashed without moving forward even by a few feet and/or taking off. What could be the issue? Feel that it does not have enough power or thrust even after having calibrated the ESC.
Have installed the following electronics:
1400 kv motor
30 amp ESC
2200 mAh battery
8" x 5" propellor

Thanking you in anticipation

K K Iyer

Crashed or nosed over?

As it's a tail dragger, hold full up elevator and full throttle for take off.
Release elevator IMMEDIATELY after takeoff.

Regards

Adel

Thanks for your reply. Do you think it's more to do with the propeller size or the power of the motor?

Vinayak jaid

You have used wrong combination motor and prop. Use 810-910kv motor with atleast 1kg thrust on 9045. You can use sunnysky 2212 910kv which is perfect for spitfire. Btw we also sell ft planes on our website.
aviatorytechnologies.in

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Adel

Thanks for the response.

What is the big difference between my motor and the motor that you recommend?


K K Iyer

#5
@Adel,

Most people on this forum seem to believe that

1. a thrust to weight ratio of 1:1 or greater is required.
This is the biggest fallacy that has prevented Indian newcomers from achieving a flight.

2. The next biggest fallacy is thinking that the motor KV indicates power.

If you wish to know more, please post the following details:

1. Wing span and chord at wing root
2. All up weight with whatever motor and lipo that you are using
3. Specs of motor. Size, Max amps/watts. You said it is 1400kv. Looks like the generic 2212 motor available in 1000, 1400 and 2200 versions.
4. Specs of Lipo. You said 2200mah. Presumably 3s and about 180gms
5. Prop. You said 8x5. That's quite reasonable for for 1400kv if you are using a generic 2212 motor
6. Does it have and undercarriage and wheels? Did you try to take off from the ground? Did it nose over? Or took off and then crashed? How did it crash? Nose dived or wing tip dropped?
7. If no undercarriage/ wheels, how did you launch it?

Regards


Edit
Alternatively, you could just see the FliteTest videos....


Adel

Thank you for your detailed reply,

Here are the answers to your questions

1) The wingspan of the plane is 42 inches. I will measure the chord at wing root and let you know.
2) the (AUW) of the plane is approximately 820 grams.
3) I am using a X2212-9 1400 kv Motor with a 30 Amp ESC. 
4) Am using a 3 cell 2200mah orange lipo battery.
6) After launching the plane nosed over and fell 5ft away.
7)The plane does not have wheels. Am hand launching it.

The chart that came with the motor says that with an 8x5 prop I will get about 800 grams of trust. Do you think that much thrust is enough for the plane to fly?


K K Iyer

Yes, the thrust is enough. (A Boeing 747 flies with a thrust to weight ratio of 27%.)

Lots of things we don't know.
Like how did you launch it?
Underhand, holding it behind the cockpit?
Or overhand, holding it behind the wing?
Too fast or two slow?
Is it balanced at the specified position of the Centre of Gravity?

If you have a video of the flight/crash, it would help to figure out the problem.

Meanwhile, please go through all the stuff available on Flitetest about this model.

Sorry that my answers are not helpful enough.
Without seeing the model and the launch, any further advice would be only guesswork...

Regards

Adel

Thanks for your reply. Shall make a video of the next launch and upload if necessary.