RC Pattern Flying Discuss all topics pertaining to RC Pattern Flying in this forum.

F3A Results - SPOILER

Reply
Old 08-06-2012, 08:46 AM
  #101
danamania
 
Join Date: Oct 2011
Location: Stewartsville, NJ
Posts: 415
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

In a pilot's primer, lift is typically depicted as the force opposing gravity; thrust is depicted as the force opposing drag (all 4 forces are shown as arrows arrayed around a profile view aircraft). Four forces at work during level powered flight. There may be some variation on this for aerobatic flight, but these fundamentals should serve us well in modeling too, I believe.
danamania is offline  
Reply With Quote
Old 08-06-2012, 08:57 AM
  #102
MTK
 
Join Date: May 2004
Location: Whippany, NJ
Posts: 5,386
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: tuny

Wings don't produce any lift in the up and down lines???? let me ask you something; does your wings have a on-off switch??? no, they ALWAYS generates lift


I KNOW for a fact that Bryan is right. if you guys don't want to try, good.

about flying in altitudes, a biplane is way better, you want the big wings up here.
On a vertical up line, the only "lift" force is generated by the powerplant. All other forces cancel.

Wings are loaded pretty close to zero, and are loaded exactly to zero if the up line is truly vertical. Wings are capable of generating lift, but do not on a vertical up (or down) line, as long at the line is truly vertical
MTK is offline  
Reply With Quote
Old 08-06-2012, 09:00 AM
  #103
tuny
 
Join Date: May 2005
Location: caracas, VENEZUELA
Posts: 615
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Tony, nobody here is treating you with disrespect so you better choose your words carefully

and NO, wings are never parasite drag!








tuny is offline  
Reply With Quote
Old 08-06-2012, 09:02 AM
  #104
TonyF
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,074
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

I'd have to modify just slightly what MTK just said. In a vertical line, the entire model, not just the wings, must be producing zero lift or the line will not track vertical. There may be very slight, near zero lift forces from the wings, the stab, the fuse, etc. But all these force vectors must total zero for the line to remain straight.
TonyF is offline  
Reply With Quote
Old 08-06-2012, 09:07 AM
  #105
TonyF
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,074
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

tuny, yes, you are. Excessive use of exclamation points and question marks is disrespectful. The tone of your posts are also disrespectful. And I don't respond all that well to threats. So please choose your words very carefully.
TonyF is offline  
Reply With Quote
Old 08-06-2012, 09:08 AM
  #106
Doug Cronkhite
Thread Starter
 
Join Date: Dec 2001
Location: San Diego, CA
Posts: 3,486
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Sorry but this is basic aerodynamics here. A wing requires angle of attack to produce lift, and in producing lift, creates INDUCED drag. General airframe drag is parasitic drag. They are VERY different things. Without angle of attack as in a purely vertical line, either up or down, the wing is NOT generating lift. If it were, the vertical line could not be maintained at all, as there is no weight for that lift to counteract, such as in level flight.

Most fixed gear installations use a roughly (very roughly) airfoil shaped gear leg. Most retracts use a round wire. In truth, the round wire (and any similar round object) is a significant increase in drag over an airfoil shaped surface. This is not theory, estimation, guesswork, or voodoo, it is aerodynamic fact. A round wire is a VERY high drag object. In truth, most people more likely switched to fixed gear setups to reduce complexity, AND reduce weight. Retracts are generally heavier than a comparable fixed gear setup.

In a purely vertical line, either up or down, there is no lift being generated by the wings. This again, is not theory, conjecture, common sense, or even voodoo. It's fact, and has been proven countless times over by aerodynamics engineers far more intelligent than me. What causes an airplane to pull the to the canopy on down lines generally is the trim required for level flight at a given airspeed, more specifically the stab trim required to counteract the nose-down pitching moment of the airfoils used on the wing. Again, basic aerodynamics.
Doug Cronkhite is online now  
Reply With Quote
Old 08-06-2012, 09:31 AM
  #107
rmh
 
rmh's Avatar
 
Join Date: Dec 2001
Location: , UT
Posts: 12,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Ditto -
Trying to come up with some miracle setup which turns off lift/drag is simply wistful thinking
The ideal setup (possible?)
has effective centers of drag n lift n thrust all pretty well lined up
THEN the proper trims or operator inputs to take care of the DIFFERENCES in airframe attitude vs gravity.
offsets are common - depending on the model and intended stability.
No miracles no magic trims - just adjust as needed .
rmh is offline  
Reply With Quote
Old 08-06-2012, 09:53 AM
  #108
tuny
 
Join Date: May 2005
Location: caracas, VENEZUELA
Posts: 615
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

I'm not insulting anyone, if you want to have an adult discussion about model airplanes, good, you are welcome, its fun and that's why we are all here, If you want to prove your points simple by insulting others then I'm done here.

my point is simple, a wing will never be parasite drag, in the up and down lines, the forces are cancelled (down trust, wind, elev trim just to name some factors) to make a straight line up or down, its about the straight line described by the airplane's trajectory, not its attitude, but the wings will not stop working, they ARE induced drag.
tuny is offline  
Reply With Quote
Old 08-06-2012, 09:55 AM
  #109
OhD
 
Join Date: Oct 2002
Location: west hills, CA
Posts: 1,116
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: TonyF

It seems that talking the science here with some is like trying to talk about evolution with a bunch of Republican Presidential candidates. Fortunately there are others here that know how to make sense from all this.

Good luck to the U.S. Team in 2013! I think this team will prove to be one of the strongest teams ever! And may very well return not only the Team Championship but also the Individual to the good ole USA. After all, it's been over a fifth of a century since the USA had an Individual Champion!
Tony you had it right in this post a few pages back. I'd modify it a little by comparing this discussion to a conservative trying to convince a socialist that liberty is more important than equality and e pluribus unum is better than multiculturalism.

I do believe that most of the cutting edge development in RC pattern is guys cutting and trying as opposed to a well thought out design approach. Do they ever sit down and define the requirements? It sounds as if they want to fly slower. If so they better lose weight like Dick H says, yet I never heard that mentioned. They talk about low end torque. I wonder what they really mean. High thrust at low aircraft velocity? It is difficult to have a discussion when we don't speak the same language.

Jim O


OhD is offline  
Reply With Quote
Old 08-06-2012, 09:59 AM
  #110
rmh
 
rmh's Avatar
 
Join Date: Dec 2001
Location: , UT
Posts: 12,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

To be a bit more specific - the INDUCED drag is a result of differences in pressure -which is, of course the basis of lift
IF there is no difference in pressure -there is no induced drag
However ANY shape moving thru the air generates some drag
- a greatly simplified explanation-
rmh is offline  
Reply With Quote
Old 08-06-2012, 10:30 AM
  #111
TonyF
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,074
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

tuny, myself and others are just trying to educate. You were insulting in your posts and I acted in kind. You apparently can't or won't get that the terms you are using are incorrect. So be it.

Jim, you're right on. I remember when I first started at NASA and tried to explain the dual rates on my TX. I know what they did but the engineer couldn't understand it. Finally after many minutes of discussion he got what I meant and he then explained that the term was incorrect. They were not dual rates, but dual gains. Lesson learned. I'm not an engineer but I did stay at a Holiday Inn Express!
TonyF is offline  
Reply With Quote
Old 08-06-2012, 10:39 AM
  #112
MTK
 
Join Date: May 2004
Location: Whippany, NJ
Posts: 5,386
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: OhD
I do believe that most of the cutting edge development in RC pattern is guys cutting and trying as opposed to a well thought out design approach. Do they ever sit down and define the requirements? It sounds as if they want to fly slower. If so they better lose weight like Dick H says, yet I never heard that mentioned. They talk about low end torque. I wonder what they really mean. High thrust at low aircraft velocity? It is difficult to have a discussion when we don't speak the same language.

Jim O
Sorry, I had to cut the political statements and observations out...

Cut and try, definitely!! Losing weight is one way, increasing lifting area is another. Personally I prefer losing weight and increasing the area, fully minimizing wing load. (Geez wish that were that EZ for my body too!) A bipe has real benefits in this regard....

Anyway, Everything benefits except possibly wind flying. I never subscribed to guys reducing wing areas in the guise of improved snaps, spins, et al. Smaller wings could compromise the overall flight envelope unless wing load is kept at reasonable level
MTK is offline  
Reply With Quote
Old 08-06-2012, 10:58 AM
  #113
apereira
 
apereira's Avatar
 
Join Date: Jun 2002
Posts: 1,626
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

This thread is really going in the wrong direction.....

I remember when Bryan said to me in a conversation he wished someone could explain what he means in formula....

Everybody pretty much has a clear idea of what happens in flight and on the up and down lines, but yes, there is lift, never desapears, but the four basic(basic because there are different components wich can add to any) vectors are then balance with its oppsite vector or force, that does not means it is not there, but it is actually cancelled via AOA etc, and most people explain things wich can only happen in ideal conditions, that, is where Bryan methods, to name someone kick in, it is a play of balance on many factors.

When I have been talking to Bryan or Chip, it amazes me how much knowledge on the ¨practical¨ field they have, I know a lot of people but when it comes to aeromodelling, there are certain persons who really tell you things that get you thinking, and they do not need to have a title to know what is going on, what is bad is when some people think they are doing others a favor but using the wrong methods and sometimes information. I do not think everyone has to prove others every word said, nor consider the fact that in a forum is very difficult to express certain things as it is going only in one direction and there is no face to face conversations.

I just wonder how did this thread got to this?
apereira is offline  
Reply With Quote
Old 08-06-2012, 11:09 AM
  #114
flyncajun
 
Join Date: Dec 2006
Location: DENHAM SPRINGS , LA
Posts: 614
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Yea Jim, your Right!

I never sit down and define a design and what it`s intended for I make it up as I go.
I trim models designed by designers all over the world with out even flying them over e-mail just by them telling me their mixes ,,I guess thats just my Cajun luck as well
I never speak proper english to have adult conversation, nor can I define things in the proper terms. it`s really hard to live my life like that.
I guess I`ve designed and kitted 15 airplanes by accident ! and, advised, helped trim , nearly half of the top fliers airplanes around the world, Including Andrew Jeski, Brett, Jason , just to name the current US guys ,and I didn`t start Yesterday.
I also designed airplanes for many of the top fliers in the world by accident that flew in the World Championships
I guess Oxai cantacts me for advise on airplane set up because I`m just lucky!
I guess those Guys just lie or make it up when they say (you fixed my Airplane)

You guys are wrapped up in manuals and pigeon holed by these limitations and cannot see the forrest for the trees.
DO you think I`m that Stupid (don`t say yes Please) I know the fundamentals of flight I`ve read everything I can get my hands on ,including the guys I`m arguing with on this post! I`m trying to display the absured with absurdity.

I don`t care what angle you think the airplane is flying coming straight down or up the wings always stay positive to the trajectory for that line therfore they always produce lift. thats why you have downline mix or down thrust.
I learned that in Kindergarden.

As far as reducing weight ,,, Wish we could, I live in the real world though, the next best thing to reducing weight is reducing wing loading, so thats the approach I took. My Bipe is the biggest lightest Bipe ever made for pattern. it was lighter than many of the electric mono`s at the TT. Do you think that was a accident! performed with no planning?
Thats what enables it fly slow , low wing loading. high drag. from two wings. and insane controlable power.
It took a lifetime of knowledge in trimming and building skill to even pull it off!
It was no Accident and without expert planning it would have never come to pass.

When you guys design and build, then produce a airplane that flys at the top levels I`ll be all ears, I love to learn,
But untill then I`ll let you keep using my trim methods to keep your airplanes flying right
And don`t think I`ve told everything I know. I`m keeping a little back just for fun! the devil is in the small details,
And it seems they are not to easy to grasp. You guys are worried about things you think just cant be possible ,While Ive been to the other side and proved them possible. and am now refining details not yet percieved by you. Thats Why I enjoy the debate.

I have a unfair advantage

Bryan
flyncajun is offline  
Reply With Quote
Old 08-06-2012, 11:39 AM
  #115
4u2nv-RCU
 
Join Date: Apr 2003
Location: Spring, TX
Posts: 365
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Quoted from previous post.

"It seems that talking the science here with some is like trying to talk about evolution with a bunch of Republican Presidential candidates. Fortunately there are others here that know how to make sense from all this."





Is it just the educated progressive democrats that get to be arrogant, act a spellchecker, correct grammer, and educate us ignorant folk?


Thank you for taking time out of you obviously busy to educate us!!!
Peace!!
4u2nv-RCU is offline  
Reply With Quote
Old 08-06-2012, 11:41 AM
  #116
gdaddy
 
gdaddy's Avatar
 
Join Date: Jun 2005
Location: West Jordan, UT
Posts: 52
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Man in Black: You've made your decision then?
Vizzini: Not remotely. Because iocane comes from Australia, as everyone knows, and Australia is entirely peopled with criminals, and criminals are used to having people not trust them, as you are not trusted by me, so I can clearly not choose the wine in front of you.
Man in Black: Truly, you have a dizzying intellect.
Vizzini: Wait till I get going! Now, where was I?
Man in Black: Australia.

Somehow, this came to mind...
gdaddy is offline  
Reply With Quote
Old 08-06-2012, 11:49 AM
  #117
gdaddy
 
gdaddy's Avatar
 
Join Date: Jun 2005
Location: West Jordan, UT
Posts: 52
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER



Actually, This One:

Vizzini: I can't compete with you physically, and you're no match for my brains.
Man in Black: You're that smart?
Vizzini: Let me put it this way. Have you ever heard of Plato, Aristotle, Socrates?
Man in Black: Yes.
Vizzini: Morons.

gdaddy is offline  
Reply With Quote
Old 08-06-2012, 12:01 PM
  #118
flyncajun
 
Join Date: Dec 2006
Location: DENHAM SPRINGS , LA
Posts: 614
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

LOL thats pretty close to what we are doing.
Why do we get so wrapped up in this stuff ,,Because we love it to no ends...

thanks for sharing that Guy,
Bryan
flyncajun is offline  
Reply With Quote
Old 08-06-2012, 12:17 PM
  #119
mups53
 
Join Date: Jan 2002
Location: Hoffman Estates, IL
Posts: 2,313
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER


Quote:
ORIGINAL: gdaddy



Actually, This One:

Vizzini: I can't compete with you physically, and you're no match for my brains.
Man in Black: You're that smart?
Vizzini: Let me put it this way. Have you ever heard of Plato, Aristotle, Socrates?
Man in Black: Yes.
Vizzini: Morons.

Princess Bride a real classic!!!!Too funny!!
mups53 is offline  
Reply With Quote
Old 08-06-2012, 12:25 PM
  #120
rmh
 
rmh's Avatar
 
Join Date: Dec 2001
Location: , UT
Posts: 12,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER





I don`t care what angle you think the airplane is flying coming straight down or up the wings always stay positive to the trajectory for that line therfore they always produce lift. thats why you have downline mix or down thrust.
I learned that in Kindergarden.
[/quote]
Have you considered that the reasons for mixes (in an effort to create a truly vertical down/upline) change AOA of wing to eliminate all lift?
If lift remains, the craft will shift in the direction of the low pressureside of the wing.
Why?
Because gravity being a persistant weak force, tugs the craft earthward and the difference in wing surface pressures at 90 degrees to vertical, will attempt to reach equalibriumwhich will shift the model as needed.
Once pressure is equal. the path will be vertical.
The caveat here is that if the vertical center of drag on the airframe is not on center of wing - -some small AOA may still be required to cancel out drag in a vertical line..
Kinda straining at gnat - I know
rmh is offline  
Reply With Quote
Old 08-06-2012, 12:32 PM
  #121
gdaddy
 
gdaddy's Avatar
 
Join Date: Jun 2005
Location: West Jordan, UT
Posts: 52
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Arrrrrrrgh!!!!!!!!!!!!!!!!

Stop!!!!!!!

gdaddy is offline  
Reply With Quote
Old 08-06-2012, 12:46 PM
  #122
rmh
 
rmh's Avatar
 
Join Date: Dec 2001
Location: , UT
Posts: 12,630
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

It's twuee-it's twuee!
rmh is offline  
Reply With Quote
Old 08-06-2012, 12:50 PM
  #123
gdaddy
 
gdaddy's Avatar
 
Join Date: Jun 2005
Location: West Jordan, UT
Posts: 52
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

Dangit DAD!!

I thoughtI told you to wait in the truck!!!!

gdaddy is offline  
Reply With Quote
Old 08-06-2012, 12:58 PM
  #124
TonyF
 
Join Date: Dec 2001
Location: Rosamond, CA
Posts: 2,074
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

4u2nv-RCU,

Well, I'm a registered Independent who voted for McCain, and I also agreed with Jim's anology. I guess my statement was anti-Republican and I should have come up with a better one. I apologize. But it was the best one I could think of at the time. Sorry!

Guy, I literally laughed out loud! Thanks!
TonyF is offline  
Reply With Quote
Old 08-06-2012, 01:10 PM
  #125
gdaddy
 
gdaddy's Avatar
 
Join Date: Jun 2005
Location: West Jordan, UT
Posts: 52
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: F3A Results - SPOILER

At work.

Going back to sleep now.........
gdaddy is offline  
Reply With Quote
Reply


Thread Tools
Search this Thread
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 07:51 AM.