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Old Mar 30, 2011, 12:08 PM
It only takes one good idea
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Fishers, Indiana
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Wing design

A 7D 3 30 11 Wing update (1 min 3 sec)


Dag
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Old Mar 30, 2011, 02:46 PM
Sponsored by Team de la Peņa
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United States, FL, Pembroke Pines
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Originally Posted by dag214 View Post
Yep!

Dag
No matter what other people say DAG, I'm with you, I think that's the correct way to go based on the information you have shared with us. I would also like to agree with invertmast's post from the B-36 thread, there are a lot of 127mm power systems out there so definitely have a look around, several of them will reliably deliver over 20 lbs of thrust using current motors, batteries and ESC's.

Regards,

- Birger
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Old Mar 30, 2011, 03:09 PM
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So, I'll ask the stupid question, What's the little yellow tab in front of the flap? A spoiler or some sort?
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Old Mar 30, 2011, 03:11 PM
It only takes one good idea
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Fishers, Indiana
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Originally Posted by magillag View Post
So, I'll ask the stupid question, What's the little yellow tab in front of the flap? A spoiler or some sort?
Sorry, forgot to post what that was. The A-7 had a blown flap. It cause the air to go up and over the flap from the bottom when deployed.

Thanks, DAG
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Old Mar 30, 2011, 07:16 PM
SENTA A PUAAA!!!
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Brazil, RJ, Miguel Pereira
Joined Apr 2007
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Nice slotted flap design, Damon!

By the way, I was looking at your air ducts design and I'm sure you can optimize'em joining both smoothly right after and before the EDF exit. It should reduce the reynolds number and the payload loss on the airflow. The bigger the duct, the lower is the turbulent flow and more effective will be your performance.

Following here, buddy!

P.S.: did you received the CD's I sent you?
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Old Mar 30, 2011, 09:23 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
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Quote:
Originally Posted by Wilian Amaral View Post
Nice slotted flap design, Damon!

By the way, I was looking at your air ducts design and I'm sure you can optimize'em joining both smoothly right after and before the EDF exit. It should reduce the reynolds number and the payload loss on the airflow. The bigger the duct, the lower is the turbulent flow and more effective will be your performance.

Following here, buddy!

P.S.: did you received the CD's I sent you?
Thanks buddy, Heck yea, think I thanked you over on the B36 thread somewhere loved the music.

Be safe, Damon
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Old Mar 31, 2011, 12:53 PM
smug in granny panties
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NorCal Silicon Valley
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Awesome project! I would seriously consider 2fans of smaller size rather than one big one on this. You always follow the math and in doing so you know real world with single you can't get over 14cells, that's where esc's are at. So we go 14 x 3.8 - 52.3volts now max amps on best cells average to 140 for long life and lotta throttle if needed. So regardless of fan you now know you can only get a best of 7300watts on the taxing end of a single system. And big systems like that are peaky, even with abundant thrust efflux for nominal flight is there when punched and gone just below, on down to non existant even half. But 2fans of smaller diameter will make more total and have broader throttle envelope. Just a thought. Also 2fans get a efficiency boost for free'usially 13percent or more.


Barry
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Old Mar 31, 2011, 07:18 PM
SENTA A PUAAA!!!
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Originally Posted by dag214 View Post
Thanks buddy, Heck yea, think I thanked you over on the B36 thread somewhere loved the music.

Be safe, Damon
Sometimes I get lost on the B-36 thread!! lol Nice to hear you liked it!
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Old Mar 31, 2011, 08:19 PM
It only takes one good idea
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Fishers, Indiana
Joined Oct 2004
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Here is a BIG updated:
My personal life is a huge thing to me, my family and my friends are tops, then I have my company which takes a ton of time, but I love what I do. My adventures seem to always take me to cool places. So I am shelving my EII since I did not hit my target date of SEFF 2011. I am putting the Emmaselle back together (takes about 3 hours, plus 3 hours to shorten the nose to off-set my A100). I am doing all of this so I can get my B-36 in the air this summer. Then I can turn and burn on my A-7D. I know some of you think I am nuts, and that is fine. I just have to weigh how to use my limited build time with what is the most important to me. The A-7D will actually happen faster this way as when I travel, or it is late at night and I can't be running dremels I get allot designed.

Thanks, DAG
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Old Mar 31, 2011, 08:52 PM
EDF rules... :)
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Joined Nov 1999
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Hi DAG,

I have been watching your design on this A-7D.Too cool. All the best with it.

Cheers,
Eric B.
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Old Apr 01, 2011, 09:51 AM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
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Quote:
Originally Posted by monkamarm2000 View Post
Awesome project! I would seriously consider 2fans of smaller size rather than one big one on this. You always follow the math and in doing so you know real world with single you can't get over 14cells, that's where esc's are at. So we go 14 x 3.8 - 52.3volts now max amps on best cells average to 140 for long life and lotta throttle if needed. So regardless of fan you now know you can only get a best of 7300watts on the taxing end of a single system. And big systems like that are peaky, even with abundant thrust efflux for nominal flight is there when punched and gone just below, on down to non existant even half. But 2fans of smaller diameter will make more total and have broader throttle envelope. Just a thought. Also 2fans get a efficiency boost for free'usially 13percent or more.


Barry
Thanks,
You are looking at this just like I am.

I don't want a system that needs 100% to take off, and 85% just to stay in the air. I think the loss of efficiency with the ducting will be made back up with the 2 motors.

Thanks!
Dag
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Old Apr 03, 2011, 03:06 AM
smug in granny panties
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NorCal Silicon Valley
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yeah ive seen it a million times guys go to 10,000 cells to upkeep an extra 2 pounds thrust adding least 2 pounds in process. and in doing so raising requirement in flight nixing the reason you started going big. and big power has short band, since its so heavy its equal on full throttle and lacking anywhere below that. a smaller twin setup will have thrust you need but always have a higher average velocity, even more so lending to each other, and are just plain lighter to build up. good example is x2 even just 10s midi fans. thats 1.2 pounds each system, almost 20 pounds thrust installed! and 225mph velocity full and still 190s backed off, and thats not including 13 percent efficiency boost of twin. go twin 100's ya got all that plus 15 percent, for about 8% weight gain.

Barry
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Old Apr 04, 2011, 08:47 PM
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dag,
Is their any particular reason you did not setup the servo so the pushrods are parallel and in-line with each other when the flaps/LE flaps are fully extended? This should reduce some of the current draw by the servo's.
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Old Apr 05, 2011, 06:10 AM
It only takes one good idea
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Fishers, Indiana
Joined Oct 2004
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Quote:
Originally Posted by invertmast View Post
dag,
Is their any particular reason you did not setup the servo so the pushrods are parallel and in-line with each other when the flaps/LE flaps are fully extended? This should reduce some of the current draw by the servo's.
That is only a mock-up to look at hinge points. Everything will change. Look at my B-36 flap systems, you will see that I design it with the lightest loads on the servos.

Thanks, Dag
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Old Apr 05, 2011, 08:46 PM
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Originally Posted by dag214 View Post
That is only a mock-up to look at hinge points. Everything will change. Look at my B-36 flap systems, you will see that I design it with the lightest loads on the servos.

Thanks, Dag
I figured you just through something in their for just that reason. Just wanted to make sure though
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