Building An Avispad to check the flight characteristics of apm....

Fuselge construction

Best of luck!
Unluckily mine has still not flown.
Crashed mine 5 times.

thank u prabal....could you pls tell what happened

In my case,
The avispad keeps banking to the left.
The ailerons were both flush during the 1st crash. It banked to the left.
2nd time, i gave right trim. Even then it turned to the left.
3rd time , i gave right rudder, i set the motor to 3deg. Right and even then it turned to  the left and cartwheeled.
I dont know what was/is wrong with the plane.
P.S - all surfaces were correct, properly set and trimmed.

actually the same thing happened in my case too... in my old avispad

Did you find any solution?
Or maybe the design is faulty.
Regards

What is the circled thingy?

the airfoil i made was not perfect.... i shifted my battery to right side....  moved the right alieron completely  up and the left completly down....

and the result

https://www.youtube.com/watch?v=hxXSWqslt0U&feature=youtu.be

a nice flying plane.... do u use landing gear

actually i am using 72mhz antenna.... its the hosuing antenna for rx...its shown

Yes i use FOUR" landing gear.😆

sometimes the launch could be a prob... thats why i asked

Was the thrust line straight ?

what is a thrust line?
I, truly speaking, do not know.

It refers to the direction of motor in relation with the central axis of the aircraft. The motor should be tilted slightly to the right and downwards , this will counteract the left tendency. And this stands true for all pullers .
Regards

Sir,
The motor was already at 4 degree down thrust and set at 2 degree right thrust on the 2nd flight.
Even then it showed no improvement
REGARDS

Prabal, is the same one I maidened? If so, at that time it just needed some downthrust. It would need to be checked thoroughly to see why it banks severely left. Maybe stab is offset.

sir,
i added more down thrust to it.
and now it will be maiden-ed again in jodhpur.
going today.
Will return on 10th.
Will be visiting Sharmas' and will meet with tanmay!

Hi Prabal, I too had this issue before. Try this "Ensure the fin is centered with the stabilizer, and that the stabilizer is level with the wings. If the horizontal stabilizer is low or high on one side, the model will screw in loops" Good luck 👍

To adjust thrust line, simple rubber bands helps many a time!

Allright will follow your advice.
thanks.

On progress

Horizontal stabilizer and vertical stabilizer attached

Completed fuselage construction

Excellent!

Thank u prabal

Sir I am not aware of this... If u tell me how to do that it all be helpful

It is only for a beginner, not for an expert like you 

Happy to hear that sir... But I am not an expert... Even if I am... Always wanted to learn things which I don't know

Ok , even though not for an " intermediate" like you   it goes like this. Pierce two toothpicks in front of the motor mount. Attach one or two rubber bands tightly enough bw them and then HotGlue it in place . Once you fly the plane, you can readjust the thrust line by pulling any side of the fuselage with rubber bands . One more advantage is that even if you crash @ nose , the motor mount will move inwards inside the fuselage ( so wont crack prop or motor) but still you can fly the plane without going home for another hot glue ( useful especially when you are "displaying"   your success in front of invited guests( kids)😀😃

Did'nt quite understand.
" the thrust line by pulling any side of the fuselage with rubber bands "

Do you still have an issue with thrust line? And how do the plane behave?

yes!   Grin
Still banking to the left!
Added right thrust but to no effect.

  Still? What I would do is 1. Redo gluing the motor straight( and at a little downward angle).
2. Keep the rudder slightly to right.
3. Make sure the wing and stab are parallel .
4.If it still banks to the left, I 'll keep two fingers under the motor shaft and centre of tail and see if it falls to left; if so, take out the wing, mark and draw a line at the centre of the wing. Keep a ruler in this line and see whether the wing is balanced at this point. Then mark the middle of the fuselage  and keep the wing aligned to this point.Now redo balancing. If this is perfect, it should fly! Even then if it keeps turning, check your transmitter for any controls by which you can adjust the position of rudder.  If still... I am clueless ; I'll call experts  

@prabal276,
Had the same problem with my Sunbird!
Reason was a slight warp in the wing, too small to be detected by eyeballing.
But taping a CF rod to each wing along the chord revealed the difference in incidence.
On a 60" wing, even an imperceptible warp was enough to need 50% rudder to correct!
Try this check. It might solve your problem.
Regards.

Also remember to balance left and right!

Okay I never had such an issue, a wing warp with depron or thermocol. Thank you Iyer sir👍

Iyer sir.... Your experience always rocks....   

@prabal you are saying that its banking... But we don't know whether its banking or turning or yawing... So please post a video

So Prabal, is it that your plane flies straight and when you try to turn left, it banks to left, is it?

Hey,
Thanks every one!
Re-glued the motor mount!
Wing and stab are parallel!
Ill check the balancing now.

Iyer sir,
Ill check the warp in the afternoon.


I dont have a video now! but will try in the evening.
 

This is similar to what happens to my plane: (just on a smaller scale!)(the plane crashes before getting inverted and the ailerons are correct!)

@SI74,
My plane banks to the left as soon as i take it off!

Hi Prabal, see whether your wing tips are pointing down. That may also cause such a roll

Will check
thanks.