Setting washout in giant scale wings

[@cha3119]

First, thank you for sharing this. As I re-enter RC after 25-30 years, now with the benefit of the internet and the immense amount of information available, I became aware of washout. I had never heard about before. You show a way to induce the twist along the wing that gives you washout. I think the wordage in the video was more complicated than it need to be. Washout is wing twist set up so the tip has less of an angle of attack, and stalls after the root. Isn't a simpler way of say "when you add washout, the root stalls before the tips"? The idea is to avoid a wing stall, or falling off on a wing in a stall, especially in a turn to final when landing (full scale OR model aircraft(!)) I would mention at about the 1:00 mark of the video you are showing the washout you put into the right wing - that wasn't obvious. The tip is towards the camera, the root away. The far board is set up parallel to and through the root chord. The meter stick is set up parallel and through the tip chord. Is the far stick also 1 meter? Ok - I think you say that. What wing reference point do you use to attach the stick and meter stick? The Spar. Then, going to the luauan table top, you were inducing same washout on the Left wing. You locked down the tip and applied twist at the root. Thanks again, I have to try this on my next projects. Are there any wings this won't work for? I.e. anything too small? Maybe not good for planes you want to fly inverted? Cheers-

[@MichaelKGizzonimo]

To see the math at the end made the entire video for Me. I had been struggling with that exact equation a few weeks ago. Didn't even know how to ask.Ended up just measuring the units of 'climb' over length from My set of plans, then building a jig. My plane isn't compound profile nor scale so I worried more about both wings being identical! I love applied science, so I was able to learn something! Thank You very much.

[@Migueldeservantes]

My Horten 229 have an 8 Degree negative angle of attack at the end of the win, and I always wonder if it was designed for the purpose of increasing stability, but you are doing totally the opposite. what is the purpose? Hope you don't mind my ignorance.

[@andpet55]

This is a great question. The " negative" angle of attack I would assume means that you have twisted the tip of the wing down at the front. This is the same thing that I have done by raising the rear of the tip. Your angle is quite high, but then from what I have found from other builders the Horten needs this for lower speed stability in corners. I don't know if the need for such high angle of washout is due to the absence of an upright fin or not. I will be posting a new video that explains the physics behind washout in a few days, but the purpose of washout is to allow the tip to remain flat relative to the airflow which keeps the aileron out of turbulent air even though the root of the wing still maintains an angle of attack which will continue lift in the turn.

[@Migueldeservantes]

andpet55 Thank you very much. I really appreciate your input.

[@spacesaver100]

andpet55 Excellent description. I have a small Fling HLG that seems to always pull to the left. The original owner, who used to fly much larger gliders, told me to check out the washout of the wings. Now I know what to look for. For a measurement of how much washout I will try to find the info on-line or use an average from measuring both wings. Cheers!!