Romeo Whisky Posted November 10, 2009 Share Posted November 10, 2009 The other day a friend asked me a question that rather stumped me for a definitive answer, even though I've faced the same problem myself and simply "made a decision" without getting advice from the experts! It concerns models with tip washout which in an August RCME article was described as follows:- "Washout is where the wing's trailing edge is twisted up at the tip relative to the root". All well and good, but when you come to align the ailerons to neutral, do you line them up with the T/E at the root or the tip? (I presume that if you align with the root, you negate the washout, but if at the tip, you effectively change the angle of incidence for a large part of the wing). Quote Link to comment Share on other sites More sharing options...
Stefan Hafner Posted November 10, 2009 Share Posted November 10, 2009 To be honest, if I were builing up the ailerons from sheet and ribs i would just build the washout into them too to preserve the wing profile. You're right in saying that if you were to allign it at the root you would negate the effect of the washout so if i had to do that i'd line it up with the tip. The best option i sstill to try and get the twist in the aileron as well as the wing Quote Link to comment Share on other sites More sharing options...
Andy Gates Posted November 10, 2009 Share Posted November 10, 2009 I would do much the same as Stefan and build ailerons which have the washout incorperated so they would line up at both the inboard and outboard trailing edges. Quote Link to comment Share on other sites More sharing options...
Romeo Whisky Posted November 10, 2009 Author Share Posted November 10, 2009 Thanks guys - but my pal and were were both talking about ARTF models (sorry to use such bad language in present company!). Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted November 10, 2009 Share Posted November 10, 2009 Washout should be incorporated into the complete wing including the ailerons so that the whole wing has a smooth twist. In that way there is no need to worry about when setting things up. I design all my models which have washout this way. Interestingly the full size Luciole is built the same way but you have to build the washout into the aileron separately. It takes a bit of setting up. Quote Link to comment Share on other sites More sharing options...
Romeo Whisky Posted November 10, 2009 Author Share Posted November 10, 2009 Sorry guys, but the answers so far amount to... "If I was going there I wouldn't start from here" We are talking abount an ARTF built-up electric model (Overlander 1.2m Tucano) where there are only three choices! 1. Align at tip2. Align at root3. Split the difference and align it half way between the two. So which is the least worst (if not ideal) solution? Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted November 10, 2009 Share Posted November 10, 2009 Align at tip, that way you get the washout out at the tip where you want it. Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted November 10, 2009 Share Posted November 10, 2009 Peter Yep -then you get the extra bit of lift where you want it .My "Ruperts Dad" ended up unintentionally with what you might call twisted ailerons and boy does it fly well !Either way up for that matter! Quote Link to comment Share on other sites More sharing options...
Andy Gates Posted November 10, 2009 Share Posted November 10, 2009 Since we are talking ARTF, then surely we should be refering you to the superb(?) instruction manual that came with the plane. But there again, it seems that this question is just hypothetical. The manufacturers ought to have supplied or fitted "warped" ailerons to suit the wings washout in the first place. Quote Link to comment Share on other sites More sharing options...
Stefan Hafner Posted November 10, 2009 Share Posted November 10, 2009 yup, defintaley at the tips Just an idea, might work depending on how the ailerons are built, but could you not twist them and then heat them up with a heat gun or iron to give them a twist. I would think that would work with a built up aileron, not sure how effictive it would be with a solid balsa one though Quote Link to comment Share on other sites More sharing options...
Romeo Whisky Posted November 11, 2009 Author Share Posted November 11, 2009 Do I gather you've got the Overlander Tucano 1.2m as well Andy? - that would explain how you know that the instructions left a lot to be desired (or worked out for yourself!). I've had mine some time, but when I built it I exchanged emails with Graham Cornford who designed it, and he was very helpful in providing the "missing info", but this issue was not one I queried with him. In fact it flies fine, both slow and fast, and TBH I can't remember how I set up the aileron neutral position. It was only when a pal was building his that I realised I hadn't given it much thought. This problem (ailerons and washout) is not uncommon with ARTFs of course, as I had the same issue with my Ripmax Mustang. Although I bow to the wisdom above, in one sense I can't see it makes much difference, since by aligning at the tip, the effect at the root is that the aileron is deflected upwards, effectively decreasing the angle of incidence. This means that the tip still has a greater angle of incidence relative to the root, so negating the washout effect to some extent. This is all getting a bit technical now but very interesting nevertheless. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted November 11, 2009 Share Posted November 11, 2009 I think that you will find that the aileron at the root is a much smaller percentage of the chord than at the tip and therefore the effective change in the angle of incidence will be much less. Draw it out. Quote Link to comment Share on other sites More sharing options...
Andy Gates Posted November 11, 2009 Share Posted November 11, 2009 Sorry to disappoint RW but I do not have this model. I was relying on my limited experience of construction manuals, especially ARTF ones which seem to get worse by an inverse proportion to the part count. That is why everything I have flown for the last 5 or so years has been scratch built from plans where there are no instructions to be wrong. Quote Link to comment Share on other sites More sharing options...
Romeo Whisky Posted November 11, 2009 Author Share Posted November 11, 2009 Thanks to all above for their input. Quote Link to comment Share on other sites More sharing options...
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