Bill Reed Posted October 7, 2017 Share Posted October 7, 2017 I am building the wings on a kit and the manual says to "angle root ribs slightly to set dihedral" . No template is supplied OR drawn on the plan. On the wing drawing there is a "raise here 10mm" note. This is 26 inches from the root rib. I drew a straight line of 26 inches then raise the end point the 10mm and with a protractor It looks to be 1.5 deg of the 90. Have I done this correct? don't want to just guess the roor ribs would like to set them right. Any help advice please? Quote Link to comment Share on other sites More sharing options...
PatMc Posted October 7, 2017 Share Posted October 7, 2017 By my calculation the angle should be 89.13° [i.e. 0.87° of the 90°]. Best to prop the tip up by 10mm with a 90° block resting against the root rib. Edited By PatMc on 07/10/2017 22:57:55 Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 8, 2017 Share Posted October 8, 2017 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted October 8, 2017 Share Posted October 8, 2017 As other say, it won't make any difference. That amount of dihedral is simply to prevent the wing looking as though it is sagging. However I have just drawn it out on my drawing board and measured it with my very large protractor and I can tell you that it is exactly 1 degree. I have designed quite a few models with no dihedral and you can't really tell the difference Peggy Sue 1 and 2 are great aerobatic models and rock steady in flight.Based on the full size Monocoupes Jezebel is another with no dihedral, again no problems Edited By Peter Miller on 08/10/2017 08:16:55 Quote Link to comment Share on other sites More sharing options...
Bill Reed Posted October 8, 2017 Author Share Posted October 8, 2017 many thanks. I am a new builder so I am going to go with no dihedral in this case. if its only cosmetic ,I like a straight look anyway. it has wing struts but I think they can be jiggled if needed. Quote Link to comment Share on other sites More sharing options...
TIM Shaw Posted October 8, 2017 Share Posted October 8, 2017 Hi Bill You don't mention what the model is - provided it has ailerons I agree with previous comments. However, should it just be rudder / elevator you will need a little dihedral. Quote Link to comment Share on other sites More sharing options...
Mike Blandford Posted October 8, 2017 Share Posted October 8, 2017 26 inches is 660.4 mm. A rightangled triangle with a hypotenuse of 660.4 mm and a short side of 10mm has an angle of 0.867 degrees. Mike. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted October 8, 2017 Share Posted October 8, 2017 If the stated dihedral angle is 10mm at 26 inches the thing has got ailerons. I am currently building a "Little Ship" .44" span, 22" semispan (Obvious I know) and no ailerons and that has 2 1/2" under each tip Edited By Peter Miller on 08/10/2017 13:07:21 Edited By Peter Miller on 08/10/2017 13:08:01 Quote Link to comment Share on other sites More sharing options...
Bill Reed Posted October 8, 2017 Author Share Posted October 8, 2017 You guys really know your stuff, it does indeed have ailerons. And the geometry sum,all very good . thanks. Quote Link to comment Share on other sites More sharing options...
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