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Old Sep 07, 2008, 08:33 PM
Now where did I leave my jar?
Murman's Avatar
USA, NC, Huntersville
Joined Jul 2008
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I finally finished my chuck glider conversion today and took it out for a maiden flight. She flew right away but needed some adjustments for trim so I slowed her down to circle back and land and when I did, she spiraled down and it was all I could do to keep her from nosing in. It broke the control horn off the elevator so I had to take her back home for repairs. I took her back out after dinner and tried again. She flys like on rails at wot but when I slow her way down she does the same spiral thing. What could be causing this? I had the same sort of problem with a 22" flying wing several months ago. It needed to be flown fast in order to stay in the air. Is there a remedy for this problem? I kind of wanted this to be able to fly fast and slow.
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Old Sep 07, 2008, 09:54 PM
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Raleigh, NC
Joined Jan 2007
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You need to increase the wing surface area... The plane is stalling at a higher rate of speed; therefore, you cannot fly this plane slow because the minute you let up on the throttle it will stall. This is exactly what was happening with my Gemini twin boom glider, it was stalling the minute I would slow it down... That's why I had to rebuild the wing to increase the surface area. It doesn't have this bad flight characteristic anymore... It flies extremely well now.

Quote:
Originally Posted by Flatulator
I finally finished my chuck glider conversion today and took it out for a maiden flight. She flew right away but needed some adjustments for trim so I slowed her down to circle back and land and when I did, she spiraled down and it was all I could do to keep her from nosing in. It broke the control horn off the elevator so I had to take her back home for repairs. I took her back out after dinner and tried again. She flys like on rails at wot but when I slow her way down she does the same spiral thing. What could be causing this? I had the same sort of problem with a 22" flying wing several months ago. It needed to be flown fast in order to stay in the air. Is there a remedy for this problem? I kind of wanted this to be able to fly fast and slow.
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Old Sep 07, 2008, 10:19 PM
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Livermore, CA
Joined Sep 2004
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Quote:
Originally Posted by timocharis
So Butch, I know you ended up at 18" wide with the WW sweep, but where did that leave the root & tip chords? Might want to try a shot at that same layout...


Dave
The tip is about 6"s, inc the ailerons(Outboard aileron is 2"s)
The center root is about 8.25"s
The root at the booms is about 8.5, inc ailerons(Inboard aileron is 1.8"s)
The boom spread is 5 5/8"s
Butch
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Old Sep 07, 2008, 10:21 PM
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Livermore, CA
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Flatulator,
It does sound like its stalling.
What is the flying weight on the 24"??
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Old Sep 07, 2008, 10:43 PM
Dave North
timocharis's Avatar
USA, CA, San Jose
Joined Apr 2004
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Thanks, Butch. That's more than enough to get the pattern!


Dave
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Old Sep 08, 2008, 05:55 AM
Now where did I leave my jar?
Murman's Avatar
USA, NC, Huntersville
Joined Jul 2008
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Quote:
Originally Posted by Butch777
Flatulator,
It does sound like its stalling.
What is the flying weight on the 24"??
8.3oz...How would I go about increasing the wing area? Larger ailerons would be about the only way I could do it on this plane.
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Old Sep 08, 2008, 01:03 PM
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Livermore, CA
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I think 8.3 ozs is a bit heavy for a short cord 24" plane to be a slowflyer.
What you have is a mini pylon plane! So just fly it fast and come in a little hot for the landings.
We're building 31" EPP Boomers with 24g outrunners at 6-7ozs, so a 24" styrofoam Boomer with a 16g outrunner should be around 4-6ozs.
My 26" EPP Boomer, with a 10g outrunner, Berg, 3 Pico servos and a 340mah 2 cell only weighs 4.1ozs and flys nice and slow.

A light wing loading is the key to slow flying along with large control surfaces and extra power. Butch
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Old Sep 08, 2008, 06:14 PM
Now where did I leave my jar?
Murman's Avatar
USA, NC, Huntersville
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I originally built it for a 500mAh 2s battery but it wouldn't balance with that so I had to use the 3s battery. I made the booms 2x the length of the root cord. If I shorten the booms and move the motor forward I will be able to use the 2 cell battery and lose about 3/4oz.
How much can I shorten the booms and still have the control that the booms provide?
Also, if I swap out the 1" ailerons for 2" ones, would it increase the wing area enough to make a difference?
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Old Sep 08, 2008, 09:21 PM
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Livermore, CA
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Quote:
Originally Posted by Flatulator
I originally built it for a 500mAh 2s battery but it wouldn't balance with that so I had to use the 3s battery. I made the booms 2x the length of the root cord. If I shorten the booms and move the motor forward I will be able to use the 2 cell battery and lose about 3/4oz.
How much can I shorten the booms and still have the control that the booms provide?
Also, if I swap out the 1" ailerons for 2" ones, would it increase the wing area enough to make a difference?
To ballance my PicoStick Boomer, I had to build a long nose and move the batt way forward, or else use a heavier batt.
The longer the booms, the longer the nose. That's why I use the swept wing design, because it moves the C/G back so it ballances alot easier.
If you shorten the booms, you won't loose much weight and it will be more pitch sensitive.
If you increase the aileron width, you'll not only increase the wing area, you'll be kinda shortning the booms in effect and the C/G will also go back some.
Moving the motor also helps a bit. On my PicoStick Boomer, I even moved the motor to the front and ran a driveshaft back. Its early in this Thread. Butch
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Old Sep 09, 2008, 08:39 PM
Now where did I leave my jar?
Murman's Avatar
USA, NC, Huntersville
Joined Jul 2008
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I had a brainstorm today (or brainfart, whichever you prefer) so I stopped by Hobby Lobby and picked up another 24" chuck glider. I have decided to make this boomer into a biplane. I figure I can double the wing surface area this way and only increase the weight by about an ounce and a half at the most. I am going to stagger the top wing forward of the original to hopefully make it balance easier. Does this sound like it will work or do you think it will crash and burn?
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Old Sep 09, 2008, 11:16 PM
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Livermore, CA
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If you have enough power to push the drag of the extra wing and get the C/G right, it should fly just fine! Hook up all the ailerons and you'll have a Rolling Boomer!!

The vertical wing seperation should be about the same or more than the wing cord, inc the ailerons. Butch
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Old Sep 10, 2008, 01:23 AM
If it flies, I will crash it
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Sorry to horn in on the thread Butch but I had a thought. I see chuck gliders at various locations all of the time but they don't seem applicable to your design. They have large, long and fairly straight wings with a fairly small root cord that tappers quickly. The thing I was wondering was, would it be possible to cut the wings of these gliders at an angle and add sweep to the wings and then add ailerons, booms and tail surfaces and such? It seems like it would work but some how it doesn't seem that easy.

Rob...
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Old Sep 10, 2008, 05:41 AM
Now where did I leave my jar?
Murman's Avatar
USA, NC, Huntersville
Joined Jul 2008
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Quote:
Originally Posted by Butch777
The vertical wing seperation should be about the same or more than the wing cord, inc the ailerons. Butch
Thanks Butch, this answered another question that was bouncing around in my head.
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Old Sep 10, 2008, 02:10 PM
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Livermore, CA
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Hi Rob,
The Boomer does ballance easier with swept wings, so one of the larger Chuck glider wings cut as a swept wing would be ok as well.
The Boomers in general can be anything with twin booms and we experiment with lots of different ideas.
The main reason I started building them was to make a pusher prop trainer, that had a larger torque prop, rather than the speed props most the trainers use like the EasyStar/WingDragon and PushECat. Butch
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Old Sep 11, 2008, 01:08 AM
If it flies, I will crash it
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USA, CO, Westminster
Joined Jan 2008
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Thanks Butch. I may try it some time. I was in Hobby Lobby tonight and they have a chuck glider called the Ultra Flier for $7.99. It has a very large wing that could be cut down from the tip end and angle cut to add sweep pretty easily. I think it might work.

I think I will give it a try as soon as I get a few other projects off the bench. It looks like a fun build and certainly fun to fly. Besides, I need something to fly when the wind blows around here.

Rob...
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