Hello everyone
I recently build an RC plane using Foam and balsa wood
But my plane is not flying when I keeping 0.75 thrust to weight ratio
Can anyone suggest me to change in the plane

My plane weight is 710 g
Prop I'm using is 10inch
Battery 2200mah
Wing span 1.2m
Motor 1400kv


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Why isn't it flying? Did You Check The CG? How did you launch it? Tell us a bit more. And, If you want to increase the Thrust, Get a motor with more power/Watt rating.

Quote from: N1i2k3 on November 21, 2019, 11:07:09 PM
Hello everyone
I recently build an RC plane using Foam and balsa wood
But my plane is not flying when I keeping 0.75 thrust to weight ratio
Can anyone suggest me to change in the plane

My plane weight is 710 g
Prop I'm using is 10inch
Battery 2200mah
Wing span 1.2m
Motor 1400kv


Sent from my Redmi K20 using Tapatalk

Just 1400 KV is NO indication of a motor! Remember - Power = torque X RPM. To swing a 10" prop needs significant torque. If your motor cannot develop the required power, the RPM will fall

For a trainer type model, the ballpark figure is 80-100 watts/lb of model weight. Start by giving the full motor specs

My motor is A2212/10T/1400kv

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Which battery are you using? With a 3S, and a 9" prop, the theoretical max power is 200 W, effective about 160 W. Try and Prop down to a 9*4.7

If still not OK, something is wrong with your model. Why not include a video?

2200mah
Battery 3s

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Try flying with a 1000Mah 3S or even a lighter lipo.  2200 3s is a large lipo.  700 Gms for 1.2 m Wingspan is a bit overweight.     

A video of your attempt to fly would be helpful in a diagnosis.

What is your prop specification ? only 10" is not the sufficient Spec.
The prop is the magic thing. Being 1400 KV running on 3S and may be 1045 prop, it may burn either motor or ESC (may be 30A). The site of the supplier recomend to use 8060 prop for 3S battery or 9050 for 2S battery as it is specified in motor manual.
I will recomend you to use 8050 prop to remain safe.
It should work like a MAGIC..

Quote from: N1i2k3 on November 21, 2019, 11:07:09 PM
Hello everyone
I recently build an RC plane using Foam and balsa wood
But my plane is not flying when I keeping 0.75 thrust to weight ratio
Can anyone suggest me to change in the plane
My plane weight is 710 g, Prop is 10inch, Battery 2200mah, Wing span 1.2m, Motor 1400kv

1. How did you figure that you have 0.75 thrust/weight ratio?
Did you measure the thrust?

2. What does 'not flying' mean?

3. Even an Airbus 320 has only about 0.25 thrust/weight

4. Remove the prop. Then test fly from a hand launch. Will identify whether the problem is with the power or the airframe

5. I have two models of about 64" span, similar to yours in size.
My Sunbird, which weighs ~450gms, cruises easily at 25watts, and flies at just over a walking pace.
My Pilatus B4, which weighs ~900gms, has a 350watt motor, can exceed 100kmph easily, (you can hear the whistle from the wingtips!) and is impossible to land in a small space.
You can see their flights either by searching on this forum, or bysearching on Youtube for posts by andiyerlko (my wife)

6. Please also see one of my old posts "how much power". I'll search and send a link.

7. Meanwhile, to get meaningful answers, you have to tell us more details. Like built to an existing successful plan or your own design, wing area, specs of motor and prop etc.

The point is to experiment. Wish you all the best with your experiments...

Regards

Yes KK Iyer Sir. They won't read. Above the top of our forum, in all page, it is written
=================================================
New to this forum or RC hobby ? Start here : The RC India Gems !
=================================================

and the required links are:
Amp Rating and Motor Size

Understanding Electrical POwer System

My Experience with a model like that needs a smaller prop... Else the prop torque will not let the plane take off.
Try smaller props 6X 4 with higher KV motors 2000 Kv and above.