Posts: 256
Joined: 8/16/2002 From: Sodertalje, SWEDEN Status: offline
Bill, good to "see" you again and many thanks for your suggestion to make a cardboard cutout to determine NP....so simple and so clever...! Must admit I never thought about it.... In fact that method is exactly what I need to stop my current headscratching over a FSW canard taking shape on my drawingboard. Will explain later here when I have scanned a top view of it. Thanks all for a very good thread and the input I have received so far. Let´s keep it flowing...!! ....Cheers/Harald
PS..guerjac, do you have more pics of your bipe, tried the address but got lost..?..bamboo and castor oil in the engine eh..? ..?.looks neat.....DS
< Message edited by canardlover -- 11/17/2004 2:46:32 PM >
Posts: 20269
Joined: 11/10/2002 From: Mary Esther, Florida, FL, USA Status: offline
Harald:
It's a common trick, or at least it used to be well known, among the people playing with model rockets. Having no in flight control the rockets must have the neutral point behind the cg, else they fly right into the ground.
Bill.
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Real Airplanes have Two Engines AMA 25139 - More than 40 years.
Posts: 256
Joined: 8/16/2002 From: Sodertalje, SWEDEN Status: offline
guerjac, that plane really has character. From the winter pic in post #252 it appears the cylinder and head has the brown varnish from castor oil... them beans are certainly good...!. So with a wooden prop your plane would be totally e.c.(environmentally correct)... ....! So you fly in snow also in France...the Alps..? We just have our first flurry of snow right now here in Sodertalje/Sweden so for me it is building season now.......Brrrrr......Cheers/Harald
Posts: 54
Joined: 11/15/2003 From: Cergy Saint Christophe, FRANCE, METROPOLITAN Status: offline
Hello Canardlover I fly near Paris where the season of snow is very short (5 days/year and not every year).
On pictures, you see A Hawkeye designed from a A4 3 views. span 96" , 2 OS90 Surpass, electrical retractable landing gear. The last one is giant Lazy Bee used to drop fresh eggs during shows. The cartridge contains 6 eggs dropped 1 by 1.
Posts: 199
Joined: 2/24/2003 From: Teesside, UNITED KINGDOM Status: offline
guerjac - lovely lovely planes! Very pretty, particularly when sitting on the snow!
Any of you canard designers built a relatively slow flying, highly manoeuverable aircraft? All the ones so far look like ther're pretty quick ships. i'm hoping to explore the other end of the flight envelope. Almost like a fun-fly canard i suppose. To this end i may experiment with fairly rearward cg positions which could be quite exciting! Unlike the taillplane on a conventional aircraft, the fore-plane on a canard design has a destabilising influence, which is why a relatively forward cg position is needed. However, i want an aircraft that is very responsive in pitch so i'm hoping to build a plane to explore this.
In terms of fin area, is it generally accepted that you need more fin area than for a conventional plane?
Posts: 871
Joined: 9/26/2004 From: San Diego,
CA, USA Status: offline
I first saw this cardboard idea in a book by Martin Simon on model airplane aerodynamics. The exact way he suggests doing it involves making the cardboard cutout of the FORWARD half of the wings, from the 50% chord line. This is pretty slick because the cg of the cardboard then "finds" the 25% point, where the cg should fall, at least on a regular airplane (non-canard). My method for canards is to cut out the front half (50%chord line forward) of both the main wing and the canard wing, which are positioned on a very light balsa stick, then balance this assembly to find the np. Of course you don't need both sides of the wings, if your design is symetrical. You then have to fudge the starting point for the cg forward from the np or the canard surface won't stall first (your plane will crash instantly). Here, rather than fudging it, I just add about 40% to the WIDTH of the canard surface cardboard shape, which will result in a cg giving this surface roughly 140% of the main wing's loading. Should work. Also, here's (maybe) a pix of my latest project. This is a 46"ws thirties style plane to be powered by a Magnum 30 four stroke/ AXI-[image][/image][image][/image]2820. I sent the dxf files to Bob Holman last week and should get the lasercut wood very soon. MM glider tech is doing the preliminary vac-forming for the wheel pants and cowl. With luck, I should be building the first prototype by this weekend. The kit (limited edition) should be ready sometime next summer, probably. Regards, Allan Flowers
Posts: 1930
Joined: 11/2/2004 From: Marysville,
WA, USA Status: offline
Talk about some good looking aircraft. I'm presently assembling materials to build a Sig Kadet Jr using the plan sheet that came with a long ago destroyed kit. I plan on doing some of the same mods as were done to the Kadet Sr posted earlier but on a slightly smaller scale. My project will use the basic Kadet fuse and go with a 6" extension on the wings to give a span of 54" instead of the plans 48" span. The wings will also have ailerons and NO DIHEDRAL, where the plans call for no ailerons and almost a 2" dihedral. The horizontal stab will get an inch or two increase in span, though I havent decided on the rudder and vertical stab. It's getting an OS 25 FP with either a MA 9-6 two blade or a 8-6 or 9-5 three blade prop. I liked the idea of the sidewinder engine mounting on the Senior, might have to look into that one. One thing I would like to find is a glass cowling. The plans call for a carved balsa bock nose, but I would prefer a glass one as it's more aerodynamic and lighter. Anyone have any ideas?
BTW, GSNUT, on that red and white Pitts, where did you get the name Charlie Hilliard? Last I knew, he was flying Christen Eagles with the Eagles exhibition team. Could you give a little history on that one?
< Message edited by Hydro Junkie -- 11/19/2004 11:38:45 AM >
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All Forums >> RC Airplanes >> Scratch Building, Aircraft Design, 3D/CAD >> RE: Any self designed AND OR plans builders out there? Post pictures! 
RE: Any self designed AND OR plans builders out there? ... - 
..?.looks neat.....DS
