Hi all I have a skysurfer v2 which was flying gracefully until 4 days back... When a minor crash had compressed the a part of thr right wing which is now given hot water treatment and a but of tape (weight is negligible)....today  I tried to fly it again but failed time and time... Here is what I do... Check all control surfaces set the throttle to 3/4 or full... Launch it... After the it just goes towards the ground with a bit of tilt towards right I have also attached some photos.... Tried trimming it too but still didn't work have attached photos of my model

http://db.tt/V1fyn0Al
http://db.tt/xyr830Z1
http://db.tt/1bcToRzn
http://db.tt/1bcToRzn

Could some one please advise what to try...

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Apart from the wing first check all other systems: CG, horizontal balance, Motor (amp, power) servos, control rods etc. You will have to use a process of elimination. From the pics the wing looks OK.

try to balance the wings.

Hope thrust angle of the motor is not changed post cash.

I will try balancing wings again... Sundaram sir, thr thrust angle has not changed
Sanjay rai sir, I will try doing that and will post

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Sanjay rai sir, what is horizontal balance... I know about cg but horizontal :?

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CG shifted left or right instead front or back.
Check the position of battery.
It's the main culprit for CG. It happens when battery chember shifted to left/right.

Please check.

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What an Idi Amin-ish way to start a day !

Sidd, perhaps I'm not using the correct technical term. CG normally refers to the plane supported so it can rotate in the vertical plane. When it is horizontal at the set CG point, the plane is balanced.

But besides the balance of the front end and back end the balance of the two sides is also important. So, the model is suspended from the tip of nose and tail, and you check if either wing dips down, indicating the side is heavy.

But from what you describe it could well be some problem relating to a control surface or motor.

Wings are balanced... But I noticed the the horizontal tail fin was not aligned with the wings horizon... It was a bit inclined towards the right. Maybe that was the culprit I'll fix that and then try to fly

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Sidd: check everything, including your motor.

Sanjay sir what should I check for in the motor... As far I as I can see... The motor working fine and the thrust angle has not changed

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Sidd, let's use some analysis here.

1. You had a crash, damaged your wing, and repaired it. The repair appears fine from the photos. Is there any other damage or misalignment? You mentioned the horizontal stab was not parallel, and rectified it.

2. Check all control surfaces. See the servos are working smoothly, and not jamming, all surfaces (rudder, elevator, ailerons) are centred properly at neutral, and have equal throws. Check the trims...are they at the same position you left them?

3. Check for warps

4. Check balance (CG and horizontal CG)

5. Check Motor. Is the power developed full? If you have a watt or ammeter it is best. If the motor is not giving full power it can lead to the dreaded tip stall.

If there is still doubt, ask an experienced flyer to check, and maybe fly.

This is what I meant by stage-wise elimination. I personally do this every once in a while on my models, and always after a very rough landing, crash or repair/modification

Good luck, and do post the outcome

Do as Sanjay sir said.
also check the the elevator servo, and the right prop direction.( pusher ).

Thankyou to every one... It seems that the horizontal fin was the problem glued it correctly and now it flies again :-)... Once again thank you everyone

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Sanjay sir... Out of curiosity I stuck a multimeter into my model's battery (wolfpack 2200 mah 3s 11.1V)
So to my amazement the reading was 13 or 14 volts I guess... and after 6 minutes of flying it became 11.3V whereas the where as the nominal voltage is 11.1V... I am confused here could you please clarify about what I just observed.
:O

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Fully charged your 3S battery will read 12.6 V. On propeller load this drops. 11.1 V is the nominal voltage. If you want long life from your LIPOs don't go below 11.1 V, and ensure the cells are always balanced.

Your "13 or 14 V I guess" is a measurement or instrument error

Ok sir Thankyou :-)

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