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Old Mar 02, 2014, 11:07 AM
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Yay, I got a box full of balsa wood delivered to my house on Friday. I jumped right in and spent most of the weekend on a marathon cutting and gluing session. It went much faster and easier than I thought. I already have the body framed up. It sure looks bigger than I imagined, but it's extremely light. I changed the supporting structure a bit as I went along based on what seemed to be wiggling too much. It still needs a bit more stiffening in the rearward section, but so far so good!
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Old Mar 02, 2014, 11:38 AM
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That really looks great.
Perhaps some shear web type of bracing in the rear will help, as long as you careful about the weight.
Also keep in mind that the skin will add some strength as well.
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Old Mar 04, 2014, 07:41 AM
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I'm not overly concerned about the weight so far. Right now, the bare bones is just a bit under 6 oz, and that's for a wing area of about 1400 square inches. I am also adding small fillets everywhere I can find a spot to put one. It's getting quite stiff now. Then I'll tackle the motor mounting structure and install some kind of area underneath where I can grab it for hand launch. Not going to put landing gear on this thing. And, I still have to figure out how I want to attach the rudder. I'll also need a hatch or two to get at the batteries and servos. Lots left to do! Next, is to go at it with some sand paper and make sure all the joints are smooth for the covering.

I just ordered some covering from Hobbyking, so I have plenty of time! At least a month!
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Old Mar 04, 2014, 08:03 AM
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Originally Posted by Barry Leger View Post
Very nicely built! I don't think you have too many braces. The extra stiffness is easily worth an extra 3/4 oz. And at five oz with the motor - it's amazingly light! I'm hoping for something in the neighbourhood of 30-35 oz RTF, my span is 36" with a length of about 53". I'm still playing around with autocad, finalizing the structure layout. I'm just about sold on a single fin and rudder (I could later add tip plates if it needs it). Now, I'm waiting for an order of balsa sticks to arrive so I can start building.

I'm also planning to use an Orange V2 3-axis gyro/receiver. I have used these on a couple of other planes, they really work.
The plane is very stable, the gyro would be good for pitch stability,it is sensitive there.

That is a BIG lifting body The size of a table!!!Your weight isn't an issue, you have lots of lifting area.

Single fin should be fine,one at the field has one,but is a gasser
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Old Mar 04, 2014, 10:28 PM
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Google the Dyke Delta.
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Old Mar 05, 2014, 07:33 AM
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Google the Dyke Delta.
I'm aware of the Dyke Delta, it's really a very different beast. The Dyke Delta is a very cool home-built plane!
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Old Mar 06, 2014, 12:43 PM
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Still working away at it. The structure is mostly complete!
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Old Mar 06, 2014, 02:53 PM
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Very nice!
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Old Mar 07, 2014, 03:55 PM
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There used to be a Guillow chuck-glider in this lifting-body type of shape. I made a conversion-to-RC of one. There is a thread here. It wasn't a very good flier...twitchy and wobbly and unstable -- but it was fun just making the thing and getting it to fly. It definitely could have benefited by a gyro, like you're planning for.
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Old Mar 08, 2014, 03:45 AM
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I see you have a single point at the c/g,instead of the cabin width break which is typical of this design.

The reason for that is so the pilot has a bigger windshield. In an r/c,its not needed. Maybe it will be more efficient?
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Old Mar 09, 2014, 06:50 PM
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I see you have a single point at the c/g,instead of the cabin width break which is typical of this design.

The reason for that is so the pilot has a bigger windshield. In an r/c,its not needed. Maybe it will be more efficient?
It may be more efficient, but mostly, I think it just looks better! If this was a full sized aircraft with side-by-side seating for two, it wouldn't be too bad to have a split windscreen.
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Old Mar 10, 2014, 05:05 PM
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Here are the results of the Flying Wing CG Calculator based on the as-built measurements (I made some modifications from the plans as I went along). Usually with these faceted aircraft, the cg is located just behind the first major break (above the pilots head), but the cg calculator shows it to be further back. So, there is some room for experiment.

CG Calculator Results = http://j.mp/1h7ZLJT
Span = 35"
Length = 51.25"
Area = 1274 sq. in
Aspect Ratio = 0.96
COG @ 20% = 15.5"
COG @ 15% = 13.5"
WL @ 33 oz = 3.73 oz/sq.ft
Cubic Loading @ 33 oz = 1.3
NTM 3536A 1400 kv with 9X6, approximately 500 to 550 watts, about 12,000 rpm.
Watts per pound at 500 wattts = 250 W/lb
Pitch Speed at 12,000 rpm = 68 mph
Static Thrust = 43 oz
Thrust to weight ratio = 1.3
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Old Mar 10, 2014, 06:02 PM
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With these type of aircraft the COG is usually set up at between 15 and 20 %. The CG you have is for 20% which is the aft limit for this plane. The stock COG is probably closer to the 15% figure.
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Old Mar 10, 2014, 06:39 PM
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Quote:
Originally Posted by iron eagle View Post
With these type of aircraft the COG is usually set up at between 15 and 20 %. The CG you have is for 20% which is the aft limit for this plane. The stock COG is probably closer to the 15% figure.
You're right! At 15% it's very close to the first break. Thanks.
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Old Mar 10, 2014, 06:52 PM
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These planes are essentially a delta as far as their flight characteristics, that is why they use a more forward COG.
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