I am scratch building a HLG on paper at this time and would like to use dihedral and not poly.

The info/questions I have are one: The wing will be 56" with a taper cord on trailing edge 7" to 3.5" and cr001sm airfoil.
how little dhedral can I use without needing ailerons? This might lead to question two.

Info/question two: I plan on a V tail if it matters. How much distance should I have from leading edge of wing to leading edge of stab for directional stability and good turning habbits with the dihedral you guys suggest I use?

Thanks in advance and as always I really appreciate your sharring of knowledge.
Ace

First off that's a pretty big chord change. You're going to run into problems with tip stall and generally poor efficiency for the tip panel area. General rule of thumb says that a 70% tip chord ratio is fairly safe. But if this is a multi break wing style that retains the chord out to near the tips then that's different. You didn't say.

How much dihedral? I wouldn't stray too far from what others use or you'll suffer from poor roll coupling and lazy turn entries. VERY bad news for HLG's that need to have snappy response to deal with small low altitude thermal.

Your best bet for this sort of thing is to plagarize and copy someone elses angles. It helps if you keep the tip panels short and fairly steeply angled so the center panels have less dihedral for efficiency. But if you carry this to extremes then you'll have lots of drag from the air spilling and turbulating around the dihedral breaks.

One solution is a five panel scheme with a flat center, slightly up angled mid outer panels and sharply upturned and very short tip panels. This puts the dihedral out at the tips where it does the most good and sharing the angle between two joints ensures the panel break turbulence is kept a bit lower...... at least that's MY story and I'm sticking to it

Numbers you ask? For 56 inches I'd say a 28 inch center panel, 8 or 10 inch mid outers and 6 inch tips. That's 30 inches but with the angles the projected span will be pretty close to your 56 inch idea. Angles would be in the order of 1 inch for the mid panels and the tips would be about 2 1/2 to 3 inches up from the base of the mid panels. That's a lot but in conjunction with a stylishly long tail moment it'll ensure very sharp and quick response to rudder inputs. Typically fuselage lengths seem to be around 70 to 80% of the wing span these days with smaller tail surfaces. The tail moment should be around 3 to 4 times the nose length.

Go to the Charles River R/C page and look at the Apogee HLG for design ideas.

http://www.charlesriverrc.org/

And at "Kahu"

...or here: http://www.soarcalgary.com/Extras/Ar...eet/index_html

Set your lift coefficient to 0.8 and aim for B=5. It'll fly fine at that point.