Tony Bennett Posted May 1, 2014 Author Share Posted May 1, 2014 i am going to build another wing ( as i like the wing) and design another fuselage for it. conventional this time. Quote Link to comment Share on other sites More sharing options...
kevin b Posted May 1, 2014 Share Posted May 1, 2014 Definitely needs floats (big ones). One under each sponson (wide spacing), well forward. If you're throwing it away, I'll pay the postage. kevinb. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 1, 2014 Share Posted May 1, 2014 It's quirky and different Tony. My concern would be the very short moment arm, which is in effect further shortened by the wing sweep in the outer panels. That combined with a fairly small tailplane area is likely to cause longitudinal instability, it could be a pig to fly. I think that all you need to do is lengthen the tail booms, perhaps by 50%. I wouldn't abandon it, I reckon that's all you need to do. Quote Link to comment Share on other sites More sharing options...
reg shaw Posted May 1, 2014 Share Posted May 1, 2014 It looks a bit like a Saab J21, excluding the extra prop position, certainly different and I like it too, although it does look a bit short in the tail moment department Ian. Edited By reg shaw on 01/05/2014 21:30:34 Edited By reg shaw on 01/05/2014 21:39:54 Quote Link to comment Share on other sites More sharing options...
GrahamWh Posted May 1, 2014 Share Posted May 1, 2014 It would look a bit like a De Havilland Vampire with the wings at shoulder position. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted May 1, 2014 Share Posted May 1, 2014 Tony I like the look of it, however I would agree with Colin about the tail boom length and size of the fins it may get you stability problems. I've designed something similar and I show a couple of photos to help you with your ideas. Edited By Mark Kettle 1 on 01/05/2014 21:39:53 Edited By Mark Kettle 1 on 01/05/2014 21:40:21 Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 1, 2014 Author Share Posted May 1, 2014 defo bin job then. i will sort larger fins and have a play with it over the next few days. nice models Mark thanks guys for the likes of the weird thing. i like designing weird looking things for the heck of it. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted May 1, 2014 Share Posted May 1, 2014 Cheers Tony, it's called Skimlander, look forward to seeing the alterations. Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 2, 2014 Author Share Posted May 2, 2014 had a silly idea this morning while drinking my coffee. what if i added an extra tailplane to the bottom of the fins with a coupled elevator, just for a laugh. got the fixed rudders to add yet, though i may use tin hinges on them ala free flight, to aid in trimming. or i could still bin it, undecided. Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted May 2, 2014 Share Posted May 2, 2014 ......forget the bin, the extra tailplane will add extra area as long its at the back Quote Link to comment Share on other sites More sharing options...
riverlandgirl. Posted May 2, 2014 Share Posted May 2, 2014 That tail moment dosen't look any shorter than a lot of flying wings. How about adding that second tail plane with a bit of negative incidence, a'la reflex? Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 2, 2014 Author Share Posted May 2, 2014 i was looking at control line stunt aircraft, they have next to no moment arm. making the non working rudders today, still umming about the second tailplane. Quote Link to comment Share on other sites More sharing options...
Martian Posted May 2, 2014 Share Posted May 2, 2014 Tony experimentation is part of our human condition go explore Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 2, 2014 Author Share Posted May 2, 2014 we have ailerons, fixed rudders and main wheels. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 2, 2014 Share Posted May 2, 2014 Tony, don't forget that control line stunters are meant to be as twitchy as possible. You could treat it as a flying wing, as riverlandgirl suggests, but the reflex is usually in the outer panels, for best stability. You'd do better perhaps with putting the reflex on the ailerons and then the small tailplane won't matter. (Done it before). Whichever way you go, it will be interesting. I hope you're well stocked with spare underpants! Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 2, 2014 Author Share Posted May 2, 2014 Quote Link to comment Share on other sites More sharing options...
Lima Hotel Foxtrot Posted May 2, 2014 Share Posted May 2, 2014 Posted by Tony Bennett on 02/05/2014 14:52:08: we have ailerons, fixed rudders and main wheels. I absolutely love the way this looks. Could twitchyness not be solved with a gyro? Quote Link to comment Share on other sites More sharing options...
kevin b Posted May 2, 2014 Share Posted May 2, 2014 Where's the floats ??? You are going to make it an open cockpit aren't you ? Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 2, 2014 Author Share Posted May 2, 2014 open cockpit sir. could try a gyro, never thought of that. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 3, 2014 Share Posted May 3, 2014 This looks great Tony, certainly distinctive! I reckon that if you followed the flying wing theme, put some reflex into the ailerons and set them up as elevons, you could forget about the elevator and not worry about the size of the tailplane or short moment arm, with the cg in the right place it would fly a treat and you wouldn't need a gyro. Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 3, 2014 Share Posted May 3, 2014 Hi Colin, can you explain aileron reflex and why it is used. Apologies for being off thread a little. Thanks Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted May 3, 2014 Author Share Posted May 3, 2014 yes i need info on that as well. will finish it soon and then have a test before greenacres. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 4, 2014 Share Posted May 4, 2014 What I'm referring to is setting both ailerons in an "up"position at neutral, the number of degrees will very depending on a number of things, perhaps 5 or 10. This reflex replaces the tailplane in longitudinally stabilising the wing. Then programming the transmitter so that for elevator input the ailerons move together up or down as elevators, but also respond as ailerons when an aileron input is made on the stick. Because the ailerons are now functioning as both ailerons and elevators they are usually referred to as "elevons" and this is common for flying wings and deltas. Sometimes the elevators are instead fitted directly to the trailing edge of the wing and in this case you have still got separate ailerons and elevators, but all on the wing trailing edge. In the Spektrum and JR transmitters the aileron/elevator mix is described as "delta" wing type, I imagine the others are the same. If I was Tony and decided to go this way, I'd make a 12" span chuck glider of the model and experiment in the back garden with the angle of "up" reflex and cg needed to get a flat glide, then use those as a starting point for the full size model. It wouldn't be far off. I think that with this approach the design wouldn't need any alteration and would fly very well. There would be no need for a separate elevator on the tailplane, it could be left fixed. With the rudders fitted, I think there is enough fin area and no further alteerations would be necessary. It's worth thinking about and is probably less work than anynother approach. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted May 4, 2014 Share Posted May 4, 2014 I forgot to mention that if you were designing a flying wing or delta from scratch, you'd probably choose an aerofoil section that had some upwards reflex built in to avoid the need to separately set the elevons in an up position, except for fine trimming. The most well known reflexed aerofoil section is probably Clark YH, which has been very widely used in full size and model aeroplanes, although a flying wing might need a bit more reflex than this provides. One reason I think that Tony's design will work well with the reflex/elevon approach is that the wide span of the ailerons is perfect for that, he couldn't have done it better if that had been his intention in the first place. Quote Link to comment Share on other sites More sharing options...
fly boy3 Posted May 4, 2014 Share Posted May 4, 2014 Hi Colin, very en lightening indeed. One more question if I may, when ail/elev are in" elevon" configuration, can I use the normal elevator trim to experiment with the reflex angle ? Thanks Quote Link to comment Share on other sites More sharing options...
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