David McCulloch Posted January 11, 2009 Share Posted January 11, 2009 Hi Peter I am building your Feugray 240 which is giving me a lot of satisfaction. It is my first build from just a plan, the query I have is the lead weight in the rudder, how much and how does it effect over all balance? David Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted January 26, 2009 Share Posted January 26, 2009 Use enough lead to get the ballance point of the rudder near the hinge line, I think my rudder balanced about 3/4" behind the hinge line. The overall balance is set with the complete model regardless of what the rudder mass balance does. Quote Link to comment Share on other sites More sharing options...
Doug Ireland Posted January 26, 2009 Share Posted January 26, 2009 Hi Peter, I've spent a lot of time studying the Feugray 240 plans and I must admit I'm a little confused as to why you would need a mass-balance on any of the flying surfaces. I can understand the need for them as well as balance tabs and anti-servo tabs on full sized AC but it seems a bit pointless on a model... I could be wrong though! Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted January 27, 2009 Share Posted January 27, 2009 The rudder is huge. You can get a condition known as flutter which can build up in a second and tear the fin off a model. I have had this happen with elevator flutter on a model, I was lucky and got it down with the tail hanging loose. Mass balances cured it. Flutter is more likely if there is any slop in the controls but can happen anyway especially with large surfaces The mass balance helps to reduce the possibility of flutter. The rudder of Feugray may not need it but if it does, then you will find out too late! My CAP 21 has mass balance weights on the Rudder and elevators. Quote Link to comment Share on other sites More sharing options...
David McCulloch Posted March 4, 2009 Author Share Posted March 4, 2009 Hi Peter further to my last query on the Feugray I cannot find a thrust line on your plan can you advise David Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted March 4, 2009 Share Posted March 4, 2009 Thrust line is always 0-0 unless otherwise stated. If, after you have flown the model you want to change that you can. I never need to. Quote Link to comment Share on other sites More sharing options...
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