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Old Aug 05, 2007, 08:36 PM
Xtreme Nut
Kuala Lumpur, Malaysia
Joined Oct 2005
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Guys ... I had no idea the carnard thermal glider design goes all the way back to the year I was born!!! Amazing ... It would be really interesting to build one that is EDF. I am crazy over EDFs for the time being.
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Old Aug 05, 2007, 09:05 PM
EDF Addicted
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United States, FL, High Springs
Joined Sep 2005
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EDF Canard flew but...

this is what she looks like now. She took off nice and straight and after about 100 feet she lifted off the runway at full power to the fan and looked great. Did a few trim passes and decided to try some manuvers. The first axial roll attempt put it into an accelerated snap but I recovered with enough altitude to pull out and fly off. After that scare I did a few more passes and everything was looking good so I tried again.This time it rolled/snap/spun/harrieried all at the same time right into terra firma.... but she might live again,with less positive incidence on the canard.
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Old Aug 05, 2007, 09:11 PM
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EDF sounds like a great choice for a canard glider with no gear and prop to worry with. The fan at the rear and the battery for balance. I trust the new EDF units are powerful enough for a hand launch? Anyone know of good unit that would pull less than 25 amps on three cells? Would 250 watts be enough? All new to me. Charles
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Old Aug 05, 2007, 09:17 PM
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Charles,my edf set-up is a Phase 3 Fantom stock fan(x fan) and 30 amp esc. Watts are around 290 and 27 amps last time I checked with a TP 2070 3 cell Extreme. I'm already looking at putting everything in a Styker, the fuse from my crash today is a write off. I sorta feel like I'm paving the way for edf canards though and that's a great feeling despite my loss
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Old Aug 05, 2007, 09:24 PM
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Mustang Ace, Congratulations on making your idea fly!!! It sounds like you had adequate power. Were you using elevons on both ends? If the fan could have been thrusting from the center rear of the fuselage you probably would have been stable. It's really great that you got some flying time from it. Charles
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Old Aug 05, 2007, 09:27 PM
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Thanks Charles. I went with aileron and canard instead of elevons and canard for simplicity and overall proof of concept. I have to say it flew great and had plenty of power and even climbed pretty well for the 5 mins it flew before meeting it's fate. I'm thinking of using the wing for yet another canard this is to much fun
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Old Aug 05, 2007, 09:31 PM
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Ace, You certainly are laying some paving. That was a good looking design and was not that your first success for a canard of your own design? Charles
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Old Aug 05, 2007, 09:42 PM
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Yes Charles that was my first sucessful canard,but certainly won't be my last,still have to fix up the Xliner and try it again,this is half of my collection
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Old Aug 05, 2007, 09:52 PM
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Hi Charles, thanks for the info on your designs. The weight and size information is also intereting to know. One thing that is still puzzling to me is why the G1 goose had nose down issue with the high thrust line, since it seems the Egret also has a high thrust line relative to the main wing.
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Old Aug 05, 2007, 09:54 PM
Xtreme Nut
Kuala Lumpur, Malaysia
Joined Oct 2005
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canard addict - I believe that getting 250W out of a 50mm (2") EDF unit on 3S is not too hard. On a simple set up I am getting 200W and on a slightly better one I am pulling 350W, both 3S and 50mm fans.

For EDF they use the baseline of 200W/lb for good performance. I suspect for 250W you can fly something in the 2.5 lbs range if its like a glider. I suspect only.
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Old Aug 06, 2007, 12:46 AM
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I wonder if it would make sense to use twin 55mm EDF units such as those from GWS with brushless motors running around 150 to 200W each. Or maybe it would be better to go with a single larger motor. Personally, I like the idea of dual inlet ducts feeding twin fans and motors. I suspect that dual inlet ducts feeding a single fan might cause a lot of air turbulence and loss of efficency, but I have zero experience in this area.
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Old Aug 06, 2007, 01:12 AM
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John ... are you going to have the fan units inside the fuse? If so then you need good ducting to ensure effective air flow. If I could I would just use a single nice fan strapped to the top of the plane. Keeps it simple.
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Old Aug 06, 2007, 02:24 AM
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My first canard will be pretty small and use a 300DF brushless motor with a small pusher prop. It should be ok for an AUW of 14oz or less. After that I'll think more seriously about future models with a EDF. If designing a plane from scratch, I think I might as well use the ducting in the fuselage - mainly for the sake of appearance. I think the efflux ducting can be really simple, just using rolled paper stuck inside the fuse bulkheads. I can imagine that inlet ducting would be a bit more difficult, so I've been reading about how to get it right.
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Old Aug 07, 2007, 02:36 PM
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Canard Thrust line Position

First let me say WOW to Mustang ACE!! You have variety there which will lead to lots of knowledge on cause and effects. Keep up the good work. John235, you have raised a great subject there about thrust lines which I have been working with since my third canard Mickey Duck made from the Soar Star.This model has a very high thrust line with just average thrust. When going into the inside loop it loses speed and stalls in the vertical position,and then pitches forward. This can be explained with my rough sketch showing it in the vertical position: At zero speed, the thrust and gravity forces are the only ones at work. The vertical COG is to the left of the thrust line and the resultant is a counter clockwise rotation which pushes the nose forward. My first balsa design, G1 red yellow has a high thrust line and down thrust which is below the wing but the motor has enough power to maintain vertical speed which allows the canard elevator to push the nose through the inside loop. Please note that the Egret is in level flight with the nose high exactly as it sits in the picture with the wing bottom level with the table. The thrust line is shown in the rough sketch which is at 1.5" below the canard and 3" above the wing. To keep the nose gear at 6" the main gear was made to keep the wing level while allowing for prop ground clearance. The same story goes with my new Delta. My Ga. Goose,G2 and silver G3 have great thrust lines due to the high wing. The thrust line is not as important with plenty of power to keep the surfaces flying in any position. Don S, I know my neck is sticking out again. The position of the thrust line at horizontal flight equilibrium with the lift and drag forces is another story. Charles
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Old Aug 07, 2007, 02:59 PM
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Thanks Charles, I'm a pretty good airplane acquirer. Started converting my Ultrafly F-16 to a canard pusher and slimmed down the fuse quite a bit, will get a few dry fit pics. Going to my lhs soon to get a stryker body for my next edf canard project
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