Can incorrect wing incidence be corrected with ail, elev, or eng thrust adjustments?
#1
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From: Wichita Falls, TX
I rebuilt a .40 size Dazzler with a 44" Hershey bar wing. I noticed (after the glue dried) that the leading edge of the wing is 3/8" higher than the trailer edge. It's almost ready to fly, but I don't know what to expect.
I'm wondering if 3/8" will make a difference. My gut says yes. Aren't there models that purposely do this?
I'm wondering if inverted flight is going to be a loss cause.
Is there any kind of correction (such as raising the ailerons a bit) that can be done without having to take the wing apart and redo it?
Your input is appreciated.
I'm wondering if 3/8" will make a difference. My gut says yes. Aren't there models that purposely do this?
I'm wondering if inverted flight is going to be a loss cause.
Is there any kind of correction (such as raising the ailerons a bit) that can be done without having to take the wing apart and redo it?
Your input is appreciated.
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From: Evansville, IN
Im no expert but I would try several degrees of down thrust. The wing will have several degrees of positive incidence making it want to lift all the time and several degrees of down thrust will help counter this. It also turns in to up thrust when inverted so it will help inverted flight as well
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From: Vineland,
NJ
What is it supposed to be? Normally when you compensate for some mis-alignment with trim or shims etc., the corrections tend to be effective for a small performance envelope. By that I mean that as your speed changes, so does your trim.
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From: Merrimack,
NH
I would not try to take a WAG on this one. 3/8" positive incidence will undoubtedly have a very significant effect on flight behavior. The best way I can think of to look for a cure is to go to RealFlight, load the Dazzler, then modify the virtual model to add positive incidence to the main wing. I think you'll have to convert the 3/8" to angular degrees to do this. See how it flies with this change. My bet is you won't like it. Then try fooling around with aileron trim. It's possible that trimming ailerons on both wings up the same 3/8" will stabilize the wing, but I would expect there would be a dramatic difference in lift between upright and inverted flight. Another solution might be to adjust horizontal tailplane incidence and engine vertical thrust offset so they are both in line with the main wing. This begins to be a real Frankenstein's monster, but could be interesting to do on the simulator. I think before I'd do anything so drastic on the model I'd just pull the wing, saw it loose or whatever, and put it back straight.
I have flown simulator models screwed up as bad as this and maybe worse. They will fly, and it is a good test of your flying skills to get them back down in one piece. But it is not an experiment I would venture to risk a good engine and radio gear on.
I have flown simulator models screwed up as bad as this and maybe worse. They will fly, and it is a good test of your flying skills to get them back down in one piece. But it is not an experiment I would venture to risk a good engine and radio gear on.
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From: Anchorage,
AK
3/8" sounds like a lot of incidence change for a .40-size wing.
I agree that the best bet is to, as Dave Platt has said, "Just start in and do the job." It's worth the effort to fix the wing incidence, rather than get into what will probably be a losing battle with trim fixes.
That's what I'd do.
I agree that the best bet is to, as Dave Platt has said, "Just start in and do the job." It's worth the effort to fix the wing incidence, rather than get into what will probably be a losing battle with trim fixes.
That's what I'd do.
#6
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From: Wichita Falls, TX
Well I went ahead and flew it. By the way I measured very carefully and the leading edge of the wing is 1/4" higher than the trailing edge (not 3/8" as I had originally thought).
It flew very well. I did have to have a little up elevator trim, but I'm not sure if that was the wing, being nose heavy, or something else.
I flew it with 15-20 mph winds (yeah I know I shouldn't have tried it, but I couldn't wait) I flew it four times on this first outing. I'm going to fly it again on a calmer day before I make any adjustments.
Thank you all for your input. As always, more input is always appreciated.
It flew very well. I did have to have a little up elevator trim, but I'm not sure if that was the wing, being nose heavy, or something else.
I flew it with 15-20 mph winds (yeah I know I shouldn't have tried it, but I couldn't wait) I flew it four times on this first outing. I'm going to fly it again on a calmer day before I make any adjustments.
Thank you all for your input. As always, more input is always appreciated.
#7
1/4 of an inch is less than 2 degrees of incidence based on a chord of 8 inches. The wing should almost always have a couple of degrees positive incidence. Is it a suprise it flew well......Nah!
I fly a special purpose plane. It is designed for the heavy lift competition in Palmdale this weekend. It has a wingspan of 118 inches. It is powered by an OS 61 FX. The plane has taken off in 200 feet with 22 pounds of steel on board (31 pound total weight) at an altitude of 4200 feet. The wing is set with an incidence of about 4 degrees. The plane flies fine with that much incidence especially when unloaded.
I fly a special purpose plane. It is designed for the heavy lift competition in Palmdale this weekend. It has a wingspan of 118 inches. It is powered by an OS 61 FX. The plane has taken off in 200 feet with 22 pounds of steel on board (31 pound total weight) at an altitude of 4200 feet. The wing is set with an incidence of about 4 degrees. The plane flies fine with that much incidence especially when unloaded.
#10
The dazzler is designed for zero incidence.....You have 1.2 degrees positive incidence. You will notice a difference when inverted. It will still fly fine. Fix it if you want. You might like how it flies better with zero incidence. You will have to apply more down elevator to fly inverted with the positive incidence.
My $.02
My $.02



