Angle of incidence with respect to tailplane?

[B.karthik]

I have a problem with providing positive angle of attack for wing with respect to tailplane.
Problem:
1.which one is correct?what is the difference in both diagrams?which one should i follow for constructing?
karthik

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[planeace]

Hi Karthick.
I don't pretend to be an expert on this subject,but having built a few models ( gliders and powered)all I can do is tell you of my experiences. Firstly you need to have a datum line from front to rear of the model. This line will pass through the wing section and the tailplane section. I have always left the tailplane parallel to this datum line, and altered the angle of the wing depending on its section,this angle is the incidence.
If you are using a fully symetrical wing section you can keep the wing at zero incidence ie parallel to the datum line. If your wing is a semi symetrical section then one degree rise of the leading edge may be needed.If you are using a flat bottom section you would probably need to raise the leading edge by two or maybe three degrees.
Once the incidence angle is set you can move the wing vertcally up or down the fuselage depending on whether the model is high,mid or low wing, but don't alter that incidence angle.
All model aircraft building is trial and error as there are so many factors that can dramatically change an aeroplanes flight characteristics. That's why ARTFs sell so well because the trial and error has been removed. (well almost).I have a book titled 'Radio Control Soaring' by Dave Hughes. I think it is out of print now but there are copies up for auction on good old Ebay. It is all about the technical stuff for building model gliders, but the principals apply to any aircraft.It has been my bible, see if you can get hold of a copy.
I hope this has been of use, and wish you all the luck with getting your pride and joy into the air.
Cheers
Anthony.