RC India

Hi,
I am planning to build a new high wing trainer, have started the design process.
i will be using a slightly different Slot and Tab Construction technique to design the model since the upper and lower sheeting is curved and Slotting and notching those accurately is not going to be easy.

Dimensions
Fuselage Length: 36"
Fuselage Height: approx 5" (Wing Lower Surface to base of fuselage). To all deisgners here: I need advice on whether the wing is too high up .
Wing Span: 48"
Chord : 9"

Images:
(http://s11.postimg.org/ql0nwg32r/Ao_LDi9w_YVX_8_Rs3z_Q_QCBNc_Qr_PElw19j_S8_B7_MW35v_Oh.jpg)

(http://s11.postimg.org/spq2unb0z/screenshot_45.png)
I wont be slotting it as shown above but slightly differently

PM replied to.

Thank you :) The Max i can raise the Thrust line is .5"

what are the drawbacks of a low thrust line?

Since Iyer sir has already replied your PM, I feel you should follow that. Iyer sir's advice is always sound. Too many opinions will lead to confusion, so I won't add to that by replying to your PM  :D

Yes. Absolutely. The design though is on the verge of scrapping, since i cannot move the thrust line much higher than a half inch :'( .

there is just no way this could be redesigned.

@Iyer Sir what are the drawbacks of a low thrust line?

The thrust line needs to pass through or at least be close to the centre of gravity as well as the effective centre of drag.
If it is too far below the centre of gravity, every time you accelerate the thrust being below the inertia position, there is a couple trying to rotate the nose up.
If it too far below the centre of drag, at high speed, more drag creates a couple trying to rotate the nose up.
The usual solution is to add some downthrust.
If the thrustline is very low, a significant amount of downthrust may be required.
(See side view of model like Skysurfer to get an idea of how much the motor may need to be angled)

There is a simple way to raise the thrust line without the motor poking over the top of the cowl.
Make the cowl higher!
Make the cowl top horizontal (say 1" below the wing bottom line) instead of sloping down all the way to the nose. See attached pic.
The nose may need to be more like on a Rolls Royce than on a Porsche!

Please do continue your efforts and do not give up easily.

Haha.   Nice analogy with the Rolls Royce and Porsche. This High Winger was designed to be a " Porsche" I based it off the "WOT Trainer". Simply because I wanted something nice and curvy. Will try out your suggestion in sometime and repost :D Thank you

With those dimensions, why don't you base your trainer on the Avispad? Great flier. Can be made very aerobatic too. Check on the forum.

You can build it from Corro, foam, depron, balsa. Size the motor according to the weight

sanjay sirs avi spad ==== awesome