I've been messing around with a cheap, high-wing "trainer" that's .46 size. I got it for two reasons. I wanted a beater that I could use to break in my new OS.46AX's and I wanted to play around with an airplane that had anhedral.

This ARF seems to prove the idea that the asian ARFs are being put together by people from the toy industry who don't have a complete grasp of flying models. But that's another thread..... Bottom line is that most of the effort so far has been to get the sucker sorted out. I haven't had much time yet to see what the anhedral does. I've mostly been flying and fixing. But most things are now fixed and the last couple of times out I've been able to check out "what anhedral does".

The wing is a semi-symmetrical. It definitely isn't flat bottom. Heck, almost none of the "flat parts" of this thing are flat or straight.... chuckle And I think it really might have been "designed" to have dihedral but that's irrelevant. The wing joiner fits into the wing boxes with so much slop that you actually could set almost any anhedral/dihedral you wished, if you ignored the angle of the root ribs. So I cut a new plywood joiner that gave 2.5degrees and fit the boxes as good as possible, and ground the root ribs to match my 2.5 (instead of their ~1degree anhedral). Anyway, the wing is semi-symmetrical and it appears that, at least with my model, the airfoil varies a bit in the two sides of the wing. One side is actually flatbottomed from the spar back to the TE while the other side of the wing never quite flattens out. That side is curved just enough that I believe it had to be the result of the ribs' shape, not just lousy construction. So in other words, the way the model flies might have something to do with the different airfoils left to right.

Back to anhedral...........

First thing I wondered about was which way the model would roll when it was yawed with the rudder. I've flown a bunch of dihedral rudder/elevator gliders that get their roll from rudder yaw. And I also wanted to see what rolling an anhedral airplane with it's ailerons would do to yaw. Two different situations, even if somewhat related or at least situations that're often confused.

But I ran into something that stopped me from testing roll induced yaw first.
Rolling the plane with ailerons might be somewhat obscured by the lifting airfoils. But with equal aileron movement, my model did have an obvious yaw to the outside of the turns. This was fouled up somewhat by the model's large difference in roll rate. It will roll to the right or clockwise at the rate I expected. It is extremely slow to roll the opposite way. I've tried to make up for the different airfoils by ironing in a bit of twist. The plane still has an obvious, although less pronounced difference in rate. It is still taking some aileron trim, but that's another story. (The ailerons were already hinged.... you can guess..... I've cut one off and reattached but really need to do the other as well.) I figured I needed to sort that out before I could rely on the yaw test giving realistic results. So I redid the worst aileron and twisted the wing some and.... There was still a fair amount of opposite yaw even after the roll rates were closer.

I've setup another servo output "wheel" so I could try differential aileron and that has reduced the yaw coming from the aileron roll. I figured I needed to reduce that before I tested the real question..... what does yaw cause the airplane to do when combined with anhedral? does it cause "opposite" roll or what?

With my model, when I try to do a flat turn with the rudder, just the thing that causes rudder/elevator gliders to roll into the turns, I get....... taa daa......... somewhat of a roll into the turn. And it appears to be about the same turning left as turning right.

So...... after all that, I'd still like anyone who has some experience with anhedral to share with me what they've experienced. Truth is, I think my little bit of experience isn't trustworthy owing to the lousy test tool. I plan to build a clean wing for the sucker (wish I'd done it right away as a matter of fact) and test again, but that'll be awhile. I got a KYOSHO P40 and a Corsair and a Cap232 (just putting the radio in as we speak) in line first......

Anyone??????