the rational of trimming
12-07-2010, 09:00 PM
#26
Senior Member
RE: the rational of trimming
ORIGINAL: speedracerntrixie
Personally I feel that a skilled pilot with a well trimmed airplane is going to do well regardless of the airplane, within reason of course. I would never expect one to be able to show up with a Kaos and take home the wood but perhaps somone who has some IMAC experience could show up with a 1/3 scale Laser and do well in sportsman against all the ''Real'' pattern airplanes.
Personally I feel that a skilled pilot with a well trimmed airplane is going to do well regardless of the airplane, within reason of course. I would never expect one to be able to show up with a Kaos and take home the wood but perhaps somone who has some IMAC experience could show up with a 1/3 scale Laser and do well in sportsman against all the ''Real'' pattern airplanes.
A purpose built scale Laser would probably win Advanced in the right hands. Maybe not the Nats but pretty much any local contest
12-08-2010, 04:10 AM
#27
RE: the rational of trimming
Why would I try to make a 2 meter plane with a flat wing?
structurally the idea is unsound and the efficiency would not be very good
You think I really don't understand this stuff?
The trimming ideas of counteracting forces is basic
How one applies those ideas -is open to discussion-
A flat wing can be the perfect wing for very small highly competitive model (5 ounce)
structurally the idea is unsound and the efficiency would not be very good
You think I really don't understand this stuff?
The trimming ideas of counteracting forces is basic
How one applies those ideas -is open to discussion-
A flat wing can be the perfect wing for very small highly competitive model (5 ounce)
12-08-2010, 08:15 AM
#28
Senior Member
RE: the rational of trimming
ORIGINAL: rmh
Why would I try to make a 2 meter plane with a flat wing?
structurally the idea is unsound and the efficiency would not be very good
You think I really don't understand this stuff?
The trimming ideas of counteracting forces is basic
How one applies those ideas -is open to discussion-
A flat wing can be the perfect wing for very small highly competitive model (5 ounce)
Why would I try to make a 2 meter plane with a flat wing?
structurally the idea is unsound and the efficiency would not be very good
You think I really don't understand this stuff?
The trimming ideas of counteracting forces is basic
How one applies those ideas -is open to discussion-
A flat wing can be the perfect wing for very small highly competitive model (5 ounce)
Finish it in typical manner (ailerons cut out, servo cutout, tube socket, etc.). Leave the TE same thickness. Fly it. I'd bet dollars to donuts it would fly fine. If anything, that super thick TE should cause considerably greater drag than typical and make for more of a constant speed set-up.
12-08-2010, 09:12 AM
#29
RE: the rational of trimming
"Why would I try to make a 2 meter plane with a flat wing?
structurally the idea is unsound and the efficiency would not be very good
You think I really don't understand this stuff?
The trimming ideas of counteracting forces is basic
How one applies those ideas -is open to discussion-
A flat wing can be the perfect wing for very small highly competitive model (5 ounce)"
LOL
We finaly agree on something however it`s not the tune you were singing in this post
http://www.rcuniverse.com/forum/m_62..._2/key_/tm.htm
I know you understand how a wing works but you refuse to believe I have a more refined trim method than your 70`s set ups.
do you think F1 racing is still using the same setups or Nascar! Nope.
Dick, foamy airfoils and set up, has no bearing on competitive Pattern models, or IMAC airplanes or sport planes for that matter, just like Pattern model airfoils , have no bearing on the full scale aerobatic airplanes. sorry they just don`t!
Bryan
12-08-2010, 11:04 PM
#31
RE: the rational of trimming
Hi Matt,
I respectfully dissagree, the airfoil has a purpose , I know you know this LOL,would it fly sure,But it would not be a pattern plane, and the mixing would be stupid!
Also Matt, thick trailing edges do nothing to slow an airplane down, Just a myth , the drag is so negligable that Hanno couldn`t tell the difference.The only thing you can do to keep constant speed ,and or help the airplane slow down and not hurt the flight envelope is to increase the inc. in the wing. this produces drag that complements the flying in all aspects. To induce drag of any kind that is not a byproduct of lift is a detriment to the total flight performance.
also, Using the biggest diameter prop possible with the flattest pitch possible and still make the sound test is the best drag inducing tool on a pattern plane. and is where the most effective drag is outside of the wings.
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
And by the way, for those interested , anhedral stabs, look cool! and thats it!. They add nothing to the flight perfecting of the airplane
if the airplane is properly setup. If it does help, your airplane is screwed up somewhere else and Anhedral in the stabs are the least of your worries!
Speedracer,
I don`t know if you compete or not!, However being able to compete, with a Dalotel and being competitive with it ,are two different things.You can fly just about anything in sportsman but by the time you get to Advanced you need a sound ,Modern, airplane, if you want to be successful.
The reason modern F3A airplanes change so much is not just for kicks. The top designers have to keep up with the current schedules. All credible airplanes are designed by top fliers around the manuevers required to be flown in the F3A unknown catalogue. This is not a game or weekend pastime for the World level pilots. All other designs and copycats, (save a few)are influenced by these changes in thought,and design.
Now, if you want to fly just for fun and attend the events and" Compete" by all means,fly what you want.
Also you say you also use" Some"incidence in you wing "but for other reasons ,I`m confused,
The only reason for positive incidence is to produce more lift without up elevator ,or the need to move the c/g back for lift .There is no other reason to do it. The reason I can tell you where to set your wing depending on what the wing area is, is ,there is no grey area regardless of the design (EVEN LARGE FUSES) and,,it`s another reason I can tell you what to change on your setup ,when you tell me where your airplane is mixing, I can tell you what to do to fix it. unless the design is a Turd !
Most everybody sets their airplanes up tail heavy, IMAC, Pattern, sport , and even more so with scale because they are always over weight
Then, the complaints of tip stall, on landing , stalling,snapping in loops, tip stalls on pullouts,high speed stall,ECT are heard, and we want to blame it on all these wonderfull aerodynamic problems,when all thats wrong, is setup and common sense fixes. I hear "Spiral slip stream" P-feffect ECT.
We use these terms with our models as excuses as to why we can`t overcome the problems or just poor flying and trimming ,it`s easier that way,and makes us feel smart because no one can prove it wrong ,and by God it came from NASA research.
I see where guys are adding stall strips to wing tips to snap or prevent it LOL Or get told to land faster, " Or,get used to it and learn to fly aerobatic models" but no one really knows how to fix it !and blame it on (it`s got the same trait as the full size model) lol ,no it`s just tail heavy and the wing need at least 1/2 degree of pos. inc. EVERY TIME! unless it`s a Brick!
One other thing I would like to mention ,I hear the term transitional lift now. What is this Exactly.
The larger fuses do make knife edge, rolling,snap performances better, But a correct wing incidence and Cg setting will give you more rudder power and better snaps with no mixing than making the fuse bigger.
The airplane does not know its flying in an upline ,knife edge or down line , the wing is less loaded ,but they are doing the same job
all the time ,lifting. you cannot just make a fuse bigger ,think that you will create lift with the fuse to compensate a small wing.
again Hogwash. take the wings off and try to take off you you will never be be able to go fast enough to take off.
On a pattern airplane ,Any wing under 900 sq inches ,trying to lift eleven -to twelve pounds will give you issues, because you will need to run your cg to 30% to get the req. angle on the wing to fly.and here is why you have mixing poor snaps tip stalls ect.
Da rock ,
Thanks for the kudo`s f3a airplanes have gone through changes in the last ten years mostly due to Power availability and has given us the ability to increase the size of the fuse and make them more scale looking.
the bigger they are the better they fly (think Mass displacemnet)
I love Bipes and with retracts this thing will be interesting!
I`m not trying to Hyjack the forum But the original post was a question about my methods, so I just want to put in my 2 cents
and refute the foolishness with 20+years of design,trim Experience and some common Sense!
Bryan
hebertcompetitiondesigns.com
I respectfully dissagree, the airfoil has a purpose , I know you know this LOL,would it fly sure,But it would not be a pattern plane, and the mixing would be stupid!
Also Matt, thick trailing edges do nothing to slow an airplane down, Just a myth , the drag is so negligable that Hanno couldn`t tell the difference.The only thing you can do to keep constant speed ,and or help the airplane slow down and not hurt the flight envelope is to increase the inc. in the wing. this produces drag that complements the flying in all aspects. To induce drag of any kind that is not a byproduct of lift is a detriment to the total flight performance.
also, Using the biggest diameter prop possible with the flattest pitch possible and still make the sound test is the best drag inducing tool on a pattern plane. and is where the most effective drag is outside of the wings.
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
And by the way, for those interested , anhedral stabs, look cool! and thats it!. They add nothing to the flight perfecting of the airplane
if the airplane is properly setup. If it does help, your airplane is screwed up somewhere else and Anhedral in the stabs are the least of your worries!
Speedracer,
I don`t know if you compete or not!, However being able to compete, with a Dalotel and being competitive with it ,are two different things.You can fly just about anything in sportsman but by the time you get to Advanced you need a sound ,Modern, airplane, if you want to be successful.
The reason modern F3A airplanes change so much is not just for kicks. The top designers have to keep up with the current schedules. All credible airplanes are designed by top fliers around the manuevers required to be flown in the F3A unknown catalogue. This is not a game or weekend pastime for the World level pilots. All other designs and copycats, (save a few)are influenced by these changes in thought,and design.
Now, if you want to fly just for fun and attend the events and" Compete" by all means,fly what you want.
Also you say you also use" Some"incidence in you wing "but for other reasons ,I`m confused,
The only reason for positive incidence is to produce more lift without up elevator ,or the need to move the c/g back for lift .There is no other reason to do it. The reason I can tell you where to set your wing depending on what the wing area is, is ,there is no grey area regardless of the design (EVEN LARGE FUSES) and,,it`s another reason I can tell you what to change on your setup ,when you tell me where your airplane is mixing, I can tell you what to do to fix it. unless the design is a Turd !
Most everybody sets their airplanes up tail heavy, IMAC, Pattern, sport , and even more so with scale because they are always over weight
Then, the complaints of tip stall, on landing , stalling,snapping in loops, tip stalls on pullouts,high speed stall,ECT are heard, and we want to blame it on all these wonderfull aerodynamic problems,when all thats wrong, is setup and common sense fixes. I hear "Spiral slip stream" P-feffect ECT.
We use these terms with our models as excuses as to why we can`t overcome the problems or just poor flying and trimming ,it`s easier that way,and makes us feel smart because no one can prove it wrong ,and by God it came from NASA research.
I see where guys are adding stall strips to wing tips to snap or prevent it LOL Or get told to land faster, " Or,get used to it and learn to fly aerobatic models" but no one really knows how to fix it !and blame it on (it`s got the same trait as the full size model) lol ,no it`s just tail heavy and the wing need at least 1/2 degree of pos. inc. EVERY TIME! unless it`s a Brick!
One other thing I would like to mention ,I hear the term transitional lift now. What is this Exactly.
The larger fuses do make knife edge, rolling,snap performances better, But a correct wing incidence and Cg setting will give you more rudder power and better snaps with no mixing than making the fuse bigger.
The airplane does not know its flying in an upline ,knife edge or down line , the wing is less loaded ,but they are doing the same job
all the time ,lifting. you cannot just make a fuse bigger ,think that you will create lift with the fuse to compensate a small wing.
again Hogwash. take the wings off and try to take off you you will never be be able to go fast enough to take off.
On a pattern airplane ,Any wing under 900 sq inches ,trying to lift eleven -to twelve pounds will give you issues, because you will need to run your cg to 30% to get the req. angle on the wing to fly.and here is why you have mixing poor snaps tip stalls ect.
Da rock ,
Thanks for the kudo`s f3a airplanes have gone through changes in the last ten years mostly due to Power availability and has given us the ability to increase the size of the fuse and make them more scale looking.
the bigger they are the better they fly (think Mass displacemnet)
I love Bipes and with retracts this thing will be interesting!
I`m not trying to Hyjack the forum But the original post was a question about my methods, so I just want to put in my 2 cents
and refute the foolishness with 20+years of design,trim Experience and some common Sense!
Bryan
hebertcompetitiondesigns.com
12-09-2010, 04:06 AM
#32
RE: the rational of trimming
Transitional lift is just what it sounds like it is
The big fuselage does the work of lifting -even at low AOA
Those who have flown the models with fuselage areas the same or more than the wing areas are well aware of hoe it permits better rolling and snapping maneuvers
Not myth
fact
FWIW even the lift of the fuselage on a 757 is figured into the total lift available
Ask George Hicks about this -perhaps you will better understand his explanation.
The big fuselage does the work of lifting -even at low AOA
Those who have flown the models with fuselage areas the same or more than the wing areas are well aware of hoe it permits better rolling and snapping maneuvers
Not myth
fact
FWIW even the lift of the fuselage on a 757 is figured into the total lift available
Ask George Hicks about this -perhaps you will better understand his explanation.
12-09-2010, 09:34 AM
#33
Senior Member
RE: the rational of trimming
ORIGINAL: flyncajun
Hi Matt,
I respectfully dissagree, the airfoil has a purpose , I know you know this LOL,would it fly sure,But it would not be a pattern plane, and the mixing would be stupid!
Also Matt, thick trailing edges do nothing to slow an airplane down, Just a myth , the drag is so negligable that Hanno couldn`t tell the difference.The only thing you can do to keep constant speed ,and or help the airplane slow down and not hurt the flight envelope is to increase the inc. in the wing. this produces drag that complements the flying in all aspects. To induce drag of any kind that is not a byproduct of lift is a detriment to the total flight performance.
also, Using the biggest diameter prop possible with the flattest pitch possible and still make the sound test is the best drag inducing tool on a pattern plane. and is where the most effective drag is outside of the wings.
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
And by the way, for those interested , anhedral stabs, look cool! and thats it!. They add nothing to the flight perfecting of the airplane
if the airplane is properly setup. If it does help, your airplane is screwed up somewhere else and Anhedral in the stabs are the least of your worries!
Speedracer,
I don`t know if you compete or not!, However being able to compete, with a Dalotel and being competitive with it ,are two different things.You can fly just about anything in sportsman but by the time you get to Advanced you need a sound ,Modern, airplane, if you want to be successful.
The reason modern F3A airplanes change so much is not just for kicks. The top designers have to keep up with the current schedules. All credible airplanes are designed by top fliers around the manuevers required to be flown in the F3A unknown catalogue. This is not a game or weekend pastime for the World level pilots. All other designs and copycats, (save a few)are influenced by these changes in thought,and design.
Now, if you want to fly just for fun and attend the events and'' Compete'' by all means,fly what you want.
Also you say you also use'' Some''incidence in you wing ''but for other reasons ,I`m confused,
The only reason for positive incidence is to produce more lift without up elevator ,or the need to move the c/g back for lift .There is no other reason to do it. The reason I can tell you where to set your wing depending on what the wing area is, is ,there is no grey area regardless of the design (EVEN LARGE FUSES) and,,it`s another reason I can tell you what to change on your setup ,when you tell me where your airplane is mixing, I can tell you what to do to fix it. unless the design is a Turd !
Most everybody sets their airplanes up tail heavy, IMAC, Pattern, sport , and even more so with scale because they are always over weight
Then, the complaints of tip stall, on landing , stalling,snapping in loops, tip stalls on pullouts,high speed stall,ECT are heard, and we want to blame it on all these wonderfull aerodynamic problems,when all thats wrong, is setup and common sense fixes. I hear ''Spiral slip stream'' P-feffect ECT.
We use these terms with our models as excuses as to why we can`t overcome the problems or just poor flying and trimming ,it`s easier that way,and makes us feel smart because no one can prove it wrong ,and by God it came from NASA research.
I see where guys are adding stall strips to wing tips to snap or prevent it LOL Or get told to land faster, '' Or,get used to it and learn to fly aerobatic models'' but no one really knows how to fix it !and blame it on (it`s got the same trait as the full size model) lol ,no it`s just tail heavy and the wing need at least 1/2 degree of pos. inc. EVERY TIME! unless it`s a Brick!
One other thing I would like to mention ,I hear the term transitional lift now. What is this Exactly.
The larger fuses do make knife edge, rolling,snap performances better, But a correct wing incidence and Cg setting will give you more rudder power and better snaps with no mixing than making the fuse bigger.
The airplane does not know its flying in an upline ,knife edge or down line , the wing is less loaded ,but they are doing the same job
all the time ,lifting. you cannot just make a fuse bigger ,think that you will create lift with the fuse to compensate a small wing.
again Hogwash. take the wings off and try to take off you you will never be be able to go fast enough to take off.
On a pattern airplane ,Any wing under 900 sq inches ,trying to lift eleven -to twelve pounds will give you issues, because you will need to run your cg to 30% to get the req. angle on the wing to fly.and here is why you have mixing poor snaps tip stalls ect.
Da rock ,
Thanks for the kudo`s f3a airplanes have gone through changes in the last ten years mostly due to Power availability and has given us the ability to increase the size of the fuse and make them more scale looking.
the bigger they are the better they fly (think Mass displacemnet)
I love Bipes and with retracts this thing will be interesting!
I`m not trying to Hyjack the forum But the original post was a question about my methods, so I just want to put in my 2 cents
and refute the foolishness with 20+years of design,trim Experience and some common Sense!
Bryan
hebertcompetitiondesigns.com
Hi Matt,
I respectfully dissagree, the airfoil has a purpose , I know you know this LOL,would it fly sure,But it would not be a pattern plane, and the mixing would be stupid!
Also Matt, thick trailing edges do nothing to slow an airplane down, Just a myth , the drag is so negligable that Hanno couldn`t tell the difference.The only thing you can do to keep constant speed ,and or help the airplane slow down and not hurt the flight envelope is to increase the inc. in the wing. this produces drag that complements the flying in all aspects. To induce drag of any kind that is not a byproduct of lift is a detriment to the total flight performance.
also, Using the biggest diameter prop possible with the flattest pitch possible and still make the sound test is the best drag inducing tool on a pattern plane. and is where the most effective drag is outside of the wings.
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
And by the way, for those interested , anhedral stabs, look cool! and thats it!. They add nothing to the flight perfecting of the airplane
if the airplane is properly setup. If it does help, your airplane is screwed up somewhere else and Anhedral in the stabs are the least of your worries!
Speedracer,
I don`t know if you compete or not!, However being able to compete, with a Dalotel and being competitive with it ,are two different things.You can fly just about anything in sportsman but by the time you get to Advanced you need a sound ,Modern, airplane, if you want to be successful.
The reason modern F3A airplanes change so much is not just for kicks. The top designers have to keep up with the current schedules. All credible airplanes are designed by top fliers around the manuevers required to be flown in the F3A unknown catalogue. This is not a game or weekend pastime for the World level pilots. All other designs and copycats, (save a few)are influenced by these changes in thought,and design.
Now, if you want to fly just for fun and attend the events and'' Compete'' by all means,fly what you want.
Also you say you also use'' Some''incidence in you wing ''but for other reasons ,I`m confused,
The only reason for positive incidence is to produce more lift without up elevator ,or the need to move the c/g back for lift .There is no other reason to do it. The reason I can tell you where to set your wing depending on what the wing area is, is ,there is no grey area regardless of the design (EVEN LARGE FUSES) and,,it`s another reason I can tell you what to change on your setup ,when you tell me where your airplane is mixing, I can tell you what to do to fix it. unless the design is a Turd !
Most everybody sets their airplanes up tail heavy, IMAC, Pattern, sport , and even more so with scale because they are always over weight
Then, the complaints of tip stall, on landing , stalling,snapping in loops, tip stalls on pullouts,high speed stall,ECT are heard, and we want to blame it on all these wonderfull aerodynamic problems,when all thats wrong, is setup and common sense fixes. I hear ''Spiral slip stream'' P-feffect ECT.
We use these terms with our models as excuses as to why we can`t overcome the problems or just poor flying and trimming ,it`s easier that way,and makes us feel smart because no one can prove it wrong ,and by God it came from NASA research.
I see where guys are adding stall strips to wing tips to snap or prevent it LOL Or get told to land faster, '' Or,get used to it and learn to fly aerobatic models'' but no one really knows how to fix it !and blame it on (it`s got the same trait as the full size model) lol ,no it`s just tail heavy and the wing need at least 1/2 degree of pos. inc. EVERY TIME! unless it`s a Brick!
One other thing I would like to mention ,I hear the term transitional lift now. What is this Exactly.
The larger fuses do make knife edge, rolling,snap performances better, But a correct wing incidence and Cg setting will give you more rudder power and better snaps with no mixing than making the fuse bigger.
The airplane does not know its flying in an upline ,knife edge or down line , the wing is less loaded ,but they are doing the same job
all the time ,lifting. you cannot just make a fuse bigger ,think that you will create lift with the fuse to compensate a small wing.
again Hogwash. take the wings off and try to take off you you will never be be able to go fast enough to take off.
On a pattern airplane ,Any wing under 900 sq inches ,trying to lift eleven -to twelve pounds will give you issues, because you will need to run your cg to 30% to get the req. angle on the wing to fly.and here is why you have mixing poor snaps tip stalls ect.
Da rock ,
Thanks for the kudo`s f3a airplanes have gone through changes in the last ten years mostly due to Power availability and has given us the ability to increase the size of the fuse and make them more scale looking.
the bigger they are the better they fly (think Mass displacemnet)
I love Bipes and with retracts this thing will be interesting!
I`m not trying to Hyjack the forum But the original post was a question about my methods, so I just want to put in my 2 cents
and refute the foolishness with 20+years of design,trim Experience and some common Sense!
Bryan
hebertcompetitiondesigns.com
One of my points is that extremely thick TEs cause lots of drag. Think air trying to get back together. Just like a truck with a squared off back. These guys found out after several decades of doing without, that if they used fairings to smooth airflow around the cab and allow it to go down the trailer, their gas mileage increased. It's efficiency.
Same truck with fairings but without the trailer, you have got the same problem as if the cab had no fairings
In a pattern model, throw efficiency out the window because it matters very little. Large wings and thick TE, (and I'm not talking 1/8" versus 1/16" here, more like 1" or more) will result in significant shift in induced drag and slow the crate faster in the areas we need it the most like power off down lines.
I am not saying that I do this because I don't and don't care for the look. I am saying that it's straight forward physics of fluid dynamics. What I do is use very thin TE's for efficient flight and increase wing area for drag. That helps the whole envelope. I also don't subscribe to the stubby wing ideas that abound nowadays.
12-09-2010, 03:37 PM
#34
RE: the rational of trimming
ORIGINAL: flyncajun
Hi Matt,
I respectfully dissagree, the airfoil has a purpose , I know you know this LOL,would it fly sure,But it would not be a pattern plane, and the mixing would be stupid!
Also Matt, thick trailing edges do nothing to slow an airplane down, Just a myth , the drag is so negligable that Hanno couldn`t tell the difference.The only thing you can do to keep constant speed ,and or help the airplane slow down and not hurt the flight envelope is to increase the inc. in the wing. this produces drag that complements the flying in all aspects. To induce drag of any kind that is not a byproduct of lift is a detriment to the total flight performance.
also, Using the biggest diameter prop possible with the flattest pitch possible and still make the sound test is the best drag inducing tool on a pattern plane. and is where the most effective drag is outside of the wings.
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
And by the way, for those interested , anhedral stabs, look cool! and thats it!. They add nothing to the flight perfecting of the airplane
if the airplane is properly setup. If it does help, your airplane is screwed up somewhere else and Anhedral in the stabs are the least of your worries!
Speedracer,
I don`t know if you compete or not!, However being able to compete, with a Dalotel and being competitive with it ,are two different things.You can fly just about anything in sportsman but by the time you get to Advanced you need a sound ,Modern, airplane, if you want to be successful.
The reason modern F3A airplanes change so much is not just for kicks. The top designers have to keep up with the current schedules. All credible airplanes are designed by top fliers around the manuevers required to be flown in the F3A unknown catalogue. This is not a game or weekend pastime for the World level pilots. All other designs and copycats, (save a few)are influenced by these changes in thought,and design.
Now, if you want to fly just for fun and attend the events and" Compete" by all means,fly what you want.
Also you say you also use" Some"incidence in you wing "but for other reasons ,I`m confused,
The only reason for positive incidence is to produce more lift without up elevator ,or the need to move the c/g back for lift .There is no other reason to do it. The reason I can tell you where to set your wing depending on what the wing area is, is ,there is no grey area regardless of the design (EVEN LARGE FUSES) and,,it`s another reason I can tell you what to change on your setup ,when you tell me where your airplane is mixing, I can tell you what to do to fix it. unless the design is a Turd !
Most everybody sets their airplanes up tail heavy, IMAC, Pattern, sport , and even more so with scale because they are always over weight
Then, the complaints of tip stall, on landing , stalling,snapping in loops, tip stalls on pullouts,high speed stall,ECT are heard, and we want to blame it on all these wonderfull aerodynamic problems,when all thats wrong, is setup and common sense fixes. I hear "Spiral slip stream" P-feffect ECT.
We use these terms with our models as excuses as to why we can`t overcome the problems or just poor flying and trimming ,it`s easier that way,and makes us feel smart because no one can prove it wrong ,and by God it came from NASA research.
I see where guys are adding stall strips to wing tips to snap or prevent it LOL Or get told to land faster, " Or,get used to it and learn to fly aerobatic models" but no one really knows how to fix it !and blame it on (it`s got the same trait as the full size model) lol ,no it`s just tail heavy and the wing need at least 1/2 degree of pos. inc. EVERY TIME! unless it`s a Brick!
One other thing I would like to mention ,I hear the term transitional lift now. What is this Exactly.
The larger fuses do make knife edge, rolling,snap performances better, But a correct wing incidence and Cg setting will give you more rudder power and better snaps with no mixing than making the fuse bigger.
The airplane does not know its flying in an upline ,knife edge or down line , the wing is less loaded ,but they are doing the same job
all the time ,lifting. you cannot just make a fuse bigger ,think that you will create lift with the fuse to compensate a small wing.
again Hogwash. take the wings off and try to take off you you will never be be able to go fast enough to take off.
On a pattern airplane ,Any wing under 900 sq inches ,trying to lift eleven -to twelve pounds will give you issues, because you will need to run your cg to 30% to get the req. angle on the wing to fly.and here is why you have mixing poor snaps tip stalls ect.
Da rock ,
Thanks for the kudo`s f3a airplanes have gone through changes in the last ten years mostly due to Power availability and has given us the ability to increase the size of the fuse and make them more scale looking.
the bigger they are the better they fly (think Mass displacemnet)
I love Bipes and with retracts this thing will be interesting!
I`m not trying to Hyjack the forum But the original post was a question about my methods, so I just want to put in my 2 cents
and refute the foolishness with 20+years of design,trim Experience and some common Sense!
Bryan
hebertcompetitiondesigns.com
Hi Matt,
I respectfully dissagree, the airfoil has a purpose , I know you know this LOL,would it fly sure,But it would not be a pattern plane, and the mixing would be stupid!
Also Matt, thick trailing edges do nothing to slow an airplane down, Just a myth , the drag is so negligable that Hanno couldn`t tell the difference.The only thing you can do to keep constant speed ,and or help the airplane slow down and not hurt the flight envelope is to increase the inc. in the wing. this produces drag that complements the flying in all aspects. To induce drag of any kind that is not a byproduct of lift is a detriment to the total flight performance.
also, Using the biggest diameter prop possible with the flattest pitch possible and still make the sound test is the best drag inducing tool on a pattern plane. and is where the most effective drag is outside of the wings.
while I`m talking Myths,
Another Big myth is lowering the stab to reduce pitch to the belly in knife edge LOL, BS. the only thing that causes the airplane to go the belly in knife edge is a tail heavy airplane Period!
And by the way, for those interested , anhedral stabs, look cool! and thats it!. They add nothing to the flight perfecting of the airplane
if the airplane is properly setup. If it does help, your airplane is screwed up somewhere else and Anhedral in the stabs are the least of your worries!
Speedracer,
I don`t know if you compete or not!, However being able to compete, with a Dalotel and being competitive with it ,are two different things.You can fly just about anything in sportsman but by the time you get to Advanced you need a sound ,Modern, airplane, if you want to be successful.
The reason modern F3A airplanes change so much is not just for kicks. The top designers have to keep up with the current schedules. All credible airplanes are designed by top fliers around the manuevers required to be flown in the F3A unknown catalogue. This is not a game or weekend pastime for the World level pilots. All other designs and copycats, (save a few)are influenced by these changes in thought,and design.
Now, if you want to fly just for fun and attend the events and" Compete" by all means,fly what you want.
Also you say you also use" Some"incidence in you wing "but for other reasons ,I`m confused,
The only reason for positive incidence is to produce more lift without up elevator ,or the need to move the c/g back for lift .There is no other reason to do it. The reason I can tell you where to set your wing depending on what the wing area is, is ,there is no grey area regardless of the design (EVEN LARGE FUSES) and,,it`s another reason I can tell you what to change on your setup ,when you tell me where your airplane is mixing, I can tell you what to do to fix it. unless the design is a Turd !
Most everybody sets their airplanes up tail heavy, IMAC, Pattern, sport , and even more so with scale because they are always over weight
Then, the complaints of tip stall, on landing , stalling,snapping in loops, tip stalls on pullouts,high speed stall,ECT are heard, and we want to blame it on all these wonderfull aerodynamic problems,when all thats wrong, is setup and common sense fixes. I hear "Spiral slip stream" P-feffect ECT.
We use these terms with our models as excuses as to why we can`t overcome the problems or just poor flying and trimming ,it`s easier that way,and makes us feel smart because no one can prove it wrong ,and by God it came from NASA research.
I see where guys are adding stall strips to wing tips to snap or prevent it LOL Or get told to land faster, " Or,get used to it and learn to fly aerobatic models" but no one really knows how to fix it !and blame it on (it`s got the same trait as the full size model) lol ,no it`s just tail heavy and the wing need at least 1/2 degree of pos. inc. EVERY TIME! unless it`s a Brick!
One other thing I would like to mention ,I hear the term transitional lift now. What is this Exactly.
The larger fuses do make knife edge, rolling,snap performances better, But a correct wing incidence and Cg setting will give you more rudder power and better snaps with no mixing than making the fuse bigger.
The airplane does not know its flying in an upline ,knife edge or down line , the wing is less loaded ,but they are doing the same job
all the time ,lifting. you cannot just make a fuse bigger ,think that you will create lift with the fuse to compensate a small wing.
again Hogwash. take the wings off and try to take off you you will never be be able to go fast enough to take off.
On a pattern airplane ,Any wing under 900 sq inches ,trying to lift eleven -to twelve pounds will give you issues, because you will need to run your cg to 30% to get the req. angle on the wing to fly.and here is why you have mixing poor snaps tip stalls ect.
Da rock ,
Thanks for the kudo`s f3a airplanes have gone through changes in the last ten years mostly due to Power availability and has given us the ability to increase the size of the fuse and make them more scale looking.
the bigger they are the better they fly (think Mass displacemnet)
I love Bipes and with retracts this thing will be interesting!
I`m not trying to Hyjack the forum But the original post was a question about my methods, so I just want to put in my 2 cents
and refute the foolishness with 20+years of design,trim Experience and some common Sense!
Bryan
hebertcompetitiondesigns.com
Bryan, I do compete, I have been flying IMAC for 13 years currently Unlimited, F3B sailplanes ( 1996 team selection finalist ) and Q500 before that. I have always been a competive pilot. I understand about keeping up with the canges in sequences each year but I am of the opinion that can be achieved mainly through setup changes in the airplane. From what I have seen over the past few years pattern airplanes have changed dramatically . I have a difficult time beleiving it all being driven by more demanding sequences. IMAC sequences have become increasingly difficult as well however a model that was competitive10 years ago will be competitive today. Point in case, while I have not won a contest with it, my 33% Laser that was designed 20 + years ago is competitive today. The only thing keeping me from higher scores is the lack of practice.
I do agree with Matt on is the drag issue but again different reasons. I like to keep the trailing edgesof the tail section thick and square. this coupled with flying wires puts a great deal of drag on the tail. I have found that the airplane tracks better and snaps hold a better line. Lots of guys with the Comp ARF airplanes will cut a slot into a CF tube and then slide it over the trailing edge of the elevators and rudder to do this very thing.
12-09-2010, 06:04 PM
#35
RE: the rational of trimming
LOL,
Well you might not believe the effort it takes to stay competitive in F3A on a world level But, trust me there is a reason we do everything the way we do it. I would not be going through the effort I do every two years if I did not have too!
I don`t expect you to understand if you are not in the top of the pattern game, it`s not possible for you to.
Unlike IMAC we have engine ,equipment, manuever changes and pattern changes every two years and I can guarantee you the airplanes we flew 4 years ago would not longer be competitive now.Trust me,I have been in the design game for over 20 years now.
If you jump into the FAI Game ,and finish in the top 10 on a regular basis you will see the reasons why airplanes are designed fresh and refined every 2 years.
As you know IMAC airplanes are bound to rules that make it impossible to design a new airplane because they follow full sized aircraft. if they were pumping out a new full scale design every 2 years you can bet they would build a model of it for IMAC as soon as it was known to exist, it`s the nature of the beast!
And no IMAC airplane designed 10 years ago would be competitive at the level the top guys fly may be in the basic class but thats about it!
Hey ,If you are into sailplanes at a "team level",You must know Fred Weaver a good friend! tell him I said Hi!
Matt I understand what you are saying,
I was just making the statement that it cannot be detected on a pattern airplane, everyone who claims it`s the reason they do, it can`t back it up, it does make the surface a little softer at nuetral.
.
The guys that have it stuck on the t/e of the rudder and elevator put it there to numb the sensitivity around neutral.(because the airplane is tail heavy) like,stick on expo
move the c/g forward and you can pull that stuff off!
Of couse I`m aware that a truck has drag on the tail gate but it still can`t be detcted until you have to fill the tank LOL
Dick
Transitional lift is a "Gadget name" and means nothing ,unless your talking helicoptors.
90% of the lift happens on the wing at all times knive edge,up lines, down lines ,the only time the fuse is lifting, is on knife edge and it`s really not very effecient then. if it was you could trim the airplane to fly the whole pattern on knife edge.you can`t.
There are no airplanes on the market in pattern or IMAC worth it`s salt that has a fuse with the same sq. as the wing.
If you try to balance the sq. inch. by making the wings smaller that 900 Sq. or just make the fuse bigger your approach is way off base and the dynamics of your trimming would be way off ,and it would be one ugly Duck!
You should know more wing area will make the airplane roll better than more fuse area.That is a fact !
Dick I know George knows his stuff but,I`m still waiting for him to design a mix free Competition airplane
anybody can cut out a foamy.
Look Dick,I`m not trying to be argumentative , just trying to cut through the BS. with common sense.
Bryan
Well you might not believe the effort it takes to stay competitive in F3A on a world level But, trust me there is a reason we do everything the way we do it. I would not be going through the effort I do every two years if I did not have too!
I don`t expect you to understand if you are not in the top of the pattern game, it`s not possible for you to.
Unlike IMAC we have engine ,equipment, manuever changes and pattern changes every two years and I can guarantee you the airplanes we flew 4 years ago would not longer be competitive now.Trust me,I have been in the design game for over 20 years now.
If you jump into the FAI Game ,and finish in the top 10 on a regular basis you will see the reasons why airplanes are designed fresh and refined every 2 years.
As you know IMAC airplanes are bound to rules that make it impossible to design a new airplane because they follow full sized aircraft. if they were pumping out a new full scale design every 2 years you can bet they would build a model of it for IMAC as soon as it was known to exist, it`s the nature of the beast!
And no IMAC airplane designed 10 years ago would be competitive at the level the top guys fly may be in the basic class but thats about it!
Hey ,If you are into sailplanes at a "team level",You must know Fred Weaver a good friend! tell him I said Hi!
Matt I understand what you are saying,
I was just making the statement that it cannot be detected on a pattern airplane, everyone who claims it`s the reason they do, it can`t back it up, it does make the surface a little softer at nuetral.
.
The guys that have it stuck on the t/e of the rudder and elevator put it there to numb the sensitivity around neutral.(because the airplane is tail heavy) like,stick on expo
move the c/g forward and you can pull that stuff off!
Of couse I`m aware that a truck has drag on the tail gate but it still can`t be detcted until you have to fill the tank LOL
Dick
Transitional lift is a "Gadget name" and means nothing ,unless your talking helicoptors.
90% of the lift happens on the wing at all times knive edge,up lines, down lines ,the only time the fuse is lifting, is on knife edge and it`s really not very effecient then. if it was you could trim the airplane to fly the whole pattern on knife edge.you can`t.
There are no airplanes on the market in pattern or IMAC worth it`s salt that has a fuse with the same sq. as the wing.
If you try to balance the sq. inch. by making the wings smaller that 900 Sq. or just make the fuse bigger your approach is way off base and the dynamics of your trimming would be way off ,and it would be one ugly Duck!
You should know more wing area will make the airplane roll better than more fuse area.That is a fact !
Dick I know George knows his stuff but,I`m still waiting for him to design a mix free Competition airplane
anybody can cut out a foamy.
Look Dick,I`m not trying to be argumentative , just trying to cut through the BS. with common sense.
Bryan
12-09-2010, 07:58 PM
#36
Senior Member
RE: the rational of trimming
ORIGINAL: flyncajun
Matt I understand what you are saying,
I was just making the statement that it cannot be detected on a pattern airplane, everyone who claims it`s the reason they do, it can`t back it up, it does make the surface a little softer at nuetral.
.
The guys that have it stuck on the t/e of the rudder and elevator put it there to numb the sensitivity around neutral.(because the airplane is tail heavy) like,stick on expo
move the c/g forward and you can pull that stuff off!
Of couse I`m aware that a truck has drag on the tail gate but it still can`t be detcted until you have to fill the tank LOL
Bryan
Matt I understand what you are saying,
I was just making the statement that it cannot be detected on a pattern airplane, everyone who claims it`s the reason they do, it can`t back it up, it does make the surface a little softer at nuetral.
.
The guys that have it stuck on the t/e of the rudder and elevator put it there to numb the sensitivity around neutral.(because the airplane is tail heavy) like,stick on expo
move the c/g forward and you can pull that stuff off!
Of couse I`m aware that a truck has drag on the tail gate but it still can`t be detcted until you have to fill the tank LOL
Bryan
Again, I'm not talking some small adjustment to thickness by add-ons at the TE. Not the same thing in regard to air flow and induced forces. I am saying it might be worth the experiment to do a real thick TE, 1" thick minimum, to see the effect. And I don't want to do that just on small surfaces like rudders or elevators. I am talking wings included. Are we gonna fly the crate like that in competition? I don't plan to. It's just an experiment for academic reasons that I won't get to try probably.
On the other hand, a spoilerflap inboard on each wing panel would produce the desired effect with no fuss no muss. Spoilerflaps are so effective, why aren't we using them in competition models??? You want to see a real S L O W downline, try a Spoilerflap
One thing I don't agree with is regarding anhedral stabs having no impact other than looks. Anhedral stabs require extra dihedral in the wing to compensate. Not a tiny bit of dihedral addition either. If a flat stab has a 3 degree wing dihedral for zero roll mix, (that's a fairly typical pattern set-up nowadays), a 7 degree anhedral stab requires about 25% greater dihedral in the wing for the same zero roll mix (or about 4 degrees of dihedral).
That, my friend, translates to real fuse side area exactly where the fuse needs it, at mid ships. It is similar to adding about a 10 sq inch dorsal a the rear of the canopy
12-09-2010, 08:33 PM
#37
Senior Member
Join Date: Nov 2006
Location: Denham Springs, LA
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RE: the rational of trimming
>There has never been nor is there presently any Pattern or IMAC aerobatic model that has the qualities you describe. Some Pattern models are close but will never get any better >than "close". There are some compromises required to get a more complete flight envelope. Sure one can add electronic mixes galore to an otherwise non-optimally trimmed model but >that isn't a real answer to the Pattern competitor.
My two cents; short and sweet; come to Baton Rouge and fly my Shinden. No mix. Straight up out of sight, straight down. No roll couple. Fact. And no, I did not trim it, but the proof is in the flying, everything else is fluff. Bottom line is, it can be done.
Brian Clemmons
D6 Advanced Champion 2010
My two cents; short and sweet; come to Baton Rouge and fly my Shinden. No mix. Straight up out of sight, straight down. No roll couple. Fact. And no, I did not trim it, but the proof is in the flying, everything else is fluff. Bottom line is, it can be done.
Brian Clemmons
D6 Advanced Champion 2010
12-09-2010, 09:08 PM
#38
RE: the rational of trimming
ORIGINAL: flyncajun
LOL,
Well you might not believe the effort it takes to stay competitive in F3A on a world level But, trust me there is a reason we do everything the way we do it. I would not be going through the effort I do every two years if I did not have too!
I don`t expect you to understand if you are not in the top of the pattern game, it`s not possible for you to.
Unlike IMAC we have engine ,equipment, manuever changes and pattern changes every two years and I can guarantee you the airplanes we flew 4 years ago would not longer be competitive now.Trust me,I have been in the design game for over 20 years now.
If you jump into the FAI Game ,and finish in the top 10 on a regular basis you will see the reasons why airplanes are designed fresh and refined every 2 years.
As you know IMAC airplanes are bound to rules that make it impossible to design a new airplane because they follow full sized aircraft. if they were pumping out a new full scale design every 2 years you can bet they would build a model of it for IMAC as soon as it was known to exist, it`s the nature of the beast!
And no IMAC airplane designed 10 years ago would be competitive at the level the top guys fly may be in the basic class but thats about it!
Hey ,If you are into sailplanes at a "team level",You must know Fred Weaver a good friend! tell him I said Hi!
Matt I understand what you are saying,
I was just making the statement that it cannot be detected on a pattern airplane, everyone who claims it`s the reason they do, it can`t back it up, it does make the surface a little softer at nuetral.
.
The guys that have it stuck on the t/e of the rudder and elevator put it there to numb the sensitivity around neutral.(because the airplane is tail heavy) like,stick on expo
move the c/g forward and you can pull that stuff off!
Of couse I`m aware that a truck has drag on the tail gate but it still can`t be detcted until you have to fill the tank LOL
Dick
Transitional lift is a "Gadget name" and means nothing ,unless your talking helicoptors.
90% of the lift happens on the wing at all times knive edge,up lines, down lines ,the only time the fuse is lifting, is on knife edge and it`s really not very effecient then. if it was you could trim the airplane to fly the whole pattern on knife edge.you can`t.
There are no airplanes on the market in pattern or IMAC worth it`s salt that has a fuse with the same sq. as the wing.
If you try to balance the sq. inch. by making the wings smaller that 900 Sq. or just make the fuse bigger your approach is way off base and the dynamics of your trimming would be way off ,and it would be one ugly Duck!
You should know more wing area will make the airplane roll better than more fuse area.That is a fact !
Dick I know George knows his stuff but,I`m still waiting for him to design a mix free Competition airplane
anybody can cut out a foamy.
Look Dick,I`m not trying to be argumentative , just trying to cut through the BS. with common sense.
Bryan
LOL,
Well you might not believe the effort it takes to stay competitive in F3A on a world level But, trust me there is a reason we do everything the way we do it. I would not be going through the effort I do every two years if I did not have too!
I don`t expect you to understand if you are not in the top of the pattern game, it`s not possible for you to.
Unlike IMAC we have engine ,equipment, manuever changes and pattern changes every two years and I can guarantee you the airplanes we flew 4 years ago would not longer be competitive now.Trust me,I have been in the design game for over 20 years now.
If you jump into the FAI Game ,and finish in the top 10 on a regular basis you will see the reasons why airplanes are designed fresh and refined every 2 years.
As you know IMAC airplanes are bound to rules that make it impossible to design a new airplane because they follow full sized aircraft. if they were pumping out a new full scale design every 2 years you can bet they would build a model of it for IMAC as soon as it was known to exist, it`s the nature of the beast!
And no IMAC airplane designed 10 years ago would be competitive at the level the top guys fly may be in the basic class but thats about it!
Hey ,If you are into sailplanes at a "team level",You must know Fred Weaver a good friend! tell him I said Hi!
Matt I understand what you are saying,
I was just making the statement that it cannot be detected on a pattern airplane, everyone who claims it`s the reason they do, it can`t back it up, it does make the surface a little softer at nuetral.
.
The guys that have it stuck on the t/e of the rudder and elevator put it there to numb the sensitivity around neutral.(because the airplane is tail heavy) like,stick on expo
move the c/g forward and you can pull that stuff off!
Of couse I`m aware that a truck has drag on the tail gate but it still can`t be detcted until you have to fill the tank LOL
Dick
Transitional lift is a "Gadget name" and means nothing ,unless your talking helicoptors.
90% of the lift happens on the wing at all times knive edge,up lines, down lines ,the only time the fuse is lifting, is on knife edge and it`s really not very effecient then. if it was you could trim the airplane to fly the whole pattern on knife edge.you can`t.
There are no airplanes on the market in pattern or IMAC worth it`s salt that has a fuse with the same sq. as the wing.
If you try to balance the sq. inch. by making the wings smaller that 900 Sq. or just make the fuse bigger your approach is way off base and the dynamics of your trimming would be way off ,and it would be one ugly Duck!
You should know more wing area will make the airplane roll better than more fuse area.That is a fact !
Dick I know George knows his stuff but,I`m still waiting for him to design a mix free Competition airplane
anybody can cut out a foamy.
Look Dick,I`m not trying to be argumentative , just trying to cut through the BS. with common sense.
Bryan
Trust me I know what dedication it takes. In 2006 I took 2nd place in the SW region points advanced class. That year I devoted 10 hours a week to practice. Because I had 3 wins in one season I was forced up to Unlimited the following year. I don't have that kind of time to spend on practice so I am not as competitive as I once was. I will strongly disagree with you stating that an airplane designed 10 years ago being competitive only in basic. The Comp ARF 3M 330 was designed around 10 years ago and is still quite popular. The old Aeroworks 330 that Sominzini flew is quite competitive. Yes I do know Fred, saw him a few months ago. He showed up at the field during one of my practice sessions. I was flying my DA 50 powered Laser through the unlimited sequence. His comment was " Man you sure make it look easy " Needless to say I was quite flattered that somone who frequently called for TOC pilots would praise my flying in such a manner.
Oh and IMAC changes sequences every year and we have a different unkown sequence every contest
12-09-2010, 09:57 PM
#39
RE: the rational of trimming
Matt,
I here you on the 18 wheelers, we can agree on that lol
And for conversation sake I agree ,having a one inch trailing edge would indeed cause enough drag to slow the flight speed down but at what end?Of what good would it do to experiment this? what good would this be designing a pattern plane. I already know what would happen. The lift of the airfoil would be so poor you would need to increase the AOA too much and the drag of this alone would slow the whole thing to a crawl, just like a foamy , but it would be unusable for anything but (just to see what it does LOL) I don`t dissagree with you here.
My comments started out on why my trimming methods work, how we ended up debating this I don`t know it`s way off the subject and meaningless to the original debate! although you know we can debate as friends.
I will dissagree on the Anhedral Stabs however, in the last 5 years I have tested 0, degrees 3 degrees 4 degrees and 6 degrees they did nothing to the dihedral effect of the wing ,they looked cool!.and you know I do my testing
The original reason they ,Hanno, Dick, "so called did this" Dick could chime in here ,(was to get the stabs in the sweetspot or in/out of the downwash of the wing, in effect lowering the stab without actually moving them )to get rid of knife edge belly tuck!
Did it work May be, but if it did ,it was a band aid to the problem. The real problem was just incidence and c/g placement.
the downwash on our airplanes are not really ,measurable and has little to do with our trimming problems our wing loading is just too light!
I found anhedral stabs did nothing to combat ,help ,improve anything from belly tuck to roll coupling problems either on my bipes, or mono`s However, I tried them on known good setups they made no difference .You mentioned 3 degrees of dihedral in the main wings on your Brio, this depends on wing position, and all my designs are mid wings so we have some differences there.
My designs use anywhere from 1/16"to 1/4"dihedral i`m not sure where that ends up in degrees,so maybe there is something to that difference.
It may seem your adding side area to your airplane with dihedral, I agree,you do,minimal, but the more dihedral you use, there is more of a exponential effect of the dihedral with hard rudder use .The more rudder you use ,like doing a knife edge loop (mostly on the exit), the more the dihedral issues will bite you, esspecially when the airspeed drops. This can cause issues with rolling loops, rolling circles , and even snaps!
What has the most effect on roll coupling with rudder application ?it`s c/g position, the more forward you run the c/g the more the dihedral effect is observed,then if you put the c/g to 35% of the mac the dihedral seems not to be enough, and will actually reverse on hard rudder( this is an issue on a lot of scale airplanes) and foamies.
Bryan
I here you on the 18 wheelers, we can agree on that lol
And for conversation sake I agree ,having a one inch trailing edge would indeed cause enough drag to slow the flight speed down but at what end?Of what good would it do to experiment this? what good would this be designing a pattern plane. I already know what would happen. The lift of the airfoil would be so poor you would need to increase the AOA too much and the drag of this alone would slow the whole thing to a crawl, just like a foamy , but it would be unusable for anything but (just to see what it does LOL) I don`t dissagree with you here.
My comments started out on why my trimming methods work, how we ended up debating this I don`t know it`s way off the subject and meaningless to the original debate! although you know we can debate as friends.
I will dissagree on the Anhedral Stabs however, in the last 5 years I have tested 0, degrees 3 degrees 4 degrees and 6 degrees they did nothing to the dihedral effect of the wing ,they looked cool!.and you know I do my testing
The original reason they ,Hanno, Dick, "so called did this" Dick could chime in here ,(was to get the stabs in the sweetspot or in/out of the downwash of the wing, in effect lowering the stab without actually moving them )to get rid of knife edge belly tuck!
Did it work May be, but if it did ,it was a band aid to the problem. The real problem was just incidence and c/g placement.
the downwash on our airplanes are not really ,measurable and has little to do with our trimming problems our wing loading is just too light!
I found anhedral stabs did nothing to combat ,help ,improve anything from belly tuck to roll coupling problems either on my bipes, or mono`s However, I tried them on known good setups they made no difference .You mentioned 3 degrees of dihedral in the main wings on your Brio, this depends on wing position, and all my designs are mid wings so we have some differences there.
My designs use anywhere from 1/16"to 1/4"dihedral i`m not sure where that ends up in degrees,so maybe there is something to that difference.
It may seem your adding side area to your airplane with dihedral, I agree,you do,minimal, but the more dihedral you use, there is more of a exponential effect of the dihedral with hard rudder use .The more rudder you use ,like doing a knife edge loop (mostly on the exit), the more the dihedral issues will bite you, esspecially when the airspeed drops. This can cause issues with rolling loops, rolling circles , and even snaps!
What has the most effect on roll coupling with rudder application ?it`s c/g position, the more forward you run the c/g the more the dihedral effect is observed,then if you put the c/g to 35% of the mac the dihedral seems not to be enough, and will actually reverse on hard rudder( this is an issue on a lot of scale airplanes) and foamies.
Bryan
12-09-2010, 10:38 PM
#40
RE: the rational of trimming
Speedracer ,
Cool I`m glad to see Fred is still sniffing around the flying field, I still have one of his airplanes in my shop!
I guess I need to call him might motivate him a little
Fred helped me get my first sponsorship (airtronics) in 1996 good hearted guy,and a good friend.
Congrats on your points finish dang fine job.
everybody enjoys this hobby at a different level, some like to build ,some like to fly, and some like to talk about building or flying,lol
It makes the hobby great!
I hope you can get some more flying time in and get back to your winning ways.
Sometimes I look at things only at a world class level, and overlook the competition at the local level.
I`m sure there are many older designs that can compete localy and do a fine job of it.
Bryan
Cool I`m glad to see Fred is still sniffing around the flying field, I still have one of his airplanes in my shop!
I guess I need to call him might motivate him a little
Fred helped me get my first sponsorship (airtronics) in 1996 good hearted guy,and a good friend.
Congrats on your points finish dang fine job.
everybody enjoys this hobby at a different level, some like to build ,some like to fly, and some like to talk about building or flying,lol
It makes the hobby great!
I hope you can get some more flying time in and get back to your winning ways.
Sometimes I look at things only at a world class level, and overlook the competition at the local level.
I`m sure there are many older designs that can compete localy and do a fine job of it.
Bryan
12-10-2010, 05:31 AM
#41
RE: the rational of trimming
Not trying to change anyone's religion about what makes things fly -
but lift on the wings occurs ONLY when the wing is opposing gravity
In vertical flight the wings don't lift -but they may vector the flight path.
The anhedral stab -which I copied from Hanno's design -was a bit of a question at first -
It actually really only comes into effect when the model is slipping -skidding (call it what you may).
Transitional lift is a description of the reassignment of the "lift" task during a maneuver where the wings are not contributing to the opposition of the forces of gravity.
Equal effective fuselage to wing area - is currently used in a number of excellent designs
and makes perfect sense as it allows the craft to remain on the same flight path with little corrective effort (trim or surface movements.)
but lift on the wings occurs ONLY when the wing is opposing gravity
In vertical flight the wings don't lift -but they may vector the flight path.
The anhedral stab -which I copied from Hanno's design -was a bit of a question at first -
It actually really only comes into effect when the model is slipping -skidding (call it what you may).
Transitional lift is a description of the reassignment of the "lift" task during a maneuver where the wings are not contributing to the opposition of the forces of gravity.
Equal effective fuselage to wing area - is currently used in a number of excellent designs
and makes perfect sense as it allows the craft to remain on the same flight path with little corrective effort (trim or surface movements.)
12-10-2010, 07:21 AM
#42
Senior Member
RE: the rational of trimming
ORIGINAL: flyncajun
I tried them on known good setups they made no difference .You mentioned 3 degrees of dihedral in the main wings on your Brio, Bryan
I tried them on known good setups they made no difference .You mentioned 3 degrees of dihedral in the main wings on your Brio, Bryan
12-10-2010, 10:07 PM
#43
RE: the rational of trimming
Ohh ! sorry Matt, I don`t know where I got Brio from,
Dick ,name me any top pattern competition model with equal wing,fuse area,
I`ll let you believe what you want , no one is going to change your mind. But, there is no one using your methods of (just fly around the pulls if your good enough) at the top of any class in competition.
The wing does the same job in a up line-down line or level flight (common sense) or the elevator trim would need to change when you pulled up (oh wait it does using your methods LOL) even though you use incredible amounts of down thrust to pull it to the belly!
I can back up what I preach (speaking of religion) or some one would have called my hand by now
My methods and designs are out there world wide, have been for 20 years, surly someone could prove me wrong, if I were all wet,
As You have seen many times in my replys to trim help threads ,where you injected your oppinions to rebutt mine , (and they are too many to count) when I told the modeler what to do to fix their particular trim problem, they alway came back and said "Thank you, you told me exactly what to do and it worked perfectly" and then others trying what I recomended came back and said, ME TOO! I tried it, it worked, you predicted the problems and fixed it.
like here below!
http://www.rcuniverse.com/forum/m_74...tm.htm#7522813
You always come back and still tell me "believe what you want but, you have no idea what your talking about" ,and there is no way what I said could really work!
Remember, I challenged you to prove me wrong ,and report back if my methods worked or not, you refused to take me up on the offer.Really ,I`m not even sure how you are able to answer so many questions on this list ,You just do a drive-by on just about every subject written!
It`s easy to do a verbal drive-by ,but it`s harder to back up what you believe to be true ,and actually help someone fix their trim problems without a puzzling exercise in mental gynastics ,instead of just plain old common sense!
Tell you what, Tell me the wing area of the airplane your currently flying, the wieght, c/g, downthrust,and wing incidence, I`ll tell you every issue you are having trim wise, where it pulls ,where it tucks, when it tip stalls and nail it on the nose! then I`ll tell you how to fix it!
Thats not religion or faith it`s experiance
Bryan
hebertcompetitiondesigns.com
Dick ,name me any top pattern competition model with equal wing,fuse area,
I`ll let you believe what you want , no one is going to change your mind. But, there is no one using your methods of (just fly around the pulls if your good enough) at the top of any class in competition.
The wing does the same job in a up line-down line or level flight (common sense) or the elevator trim would need to change when you pulled up (oh wait it does using your methods LOL) even though you use incredible amounts of down thrust to pull it to the belly!
I can back up what I preach (speaking of religion) or some one would have called my hand by now
My methods and designs are out there world wide, have been for 20 years, surly someone could prove me wrong, if I were all wet,
As You have seen many times in my replys to trim help threads ,where you injected your oppinions to rebutt mine , (and they are too many to count)
when I told the modeler what to do to fix their particular trim problem, they alway came back and said "Thank you, you told me exactly what to do and it worked perfectly" and then others trying what I recomended came back and said, ME TOO! I tried it, it worked, you predicted the problems and fixed it.like here below!
http://www.rcuniverse.com/forum/m_74...tm.htm#7522813
You always come back and still tell me "believe what you want but, you have no idea what your talking about" ,and there is no way what I said could really work!
Remember, I challenged you to prove me wrong ,and report back if my methods worked or not, you refused to take me up on the offer.Really ,I`m not even sure how you are able to answer so many questions on this list ,You just do a drive-by on just about every subject written!
It`s easy to do a verbal drive-by ,but it`s harder to back up what you believe to be true ,and actually help someone fix their trim problems without a puzzling exercise in mental gynastics ,instead of just plain old common sense!
Tell you what, Tell me the wing area of the airplane your currently flying, the wieght, c/g, downthrust,and wing incidence, I`ll tell you every issue you are having trim wise, where it pulls ,where it tucks, when it tip stalls and nail it on the nose! then I`ll tell you how to fix it!
Thats not religion or faith it`s experiance
Bryan
hebertcompetitiondesigns.com
12-11-2010, 04:00 AM
#44
Senior Member
RE: the rational of trimming
This thread has become a bit too personal.
The posts have gotten more and more like personal messages. Discussing the topic instead of each other helps keep the threads worthwhile for others, and gets across each side of the issue better. Confrontations between individuals need to be taken elsewhere.
Let's take a break. This thread is locked.
The posts have gotten more and more like personal messages. Discussing the topic instead of each other helps keep the threads worthwhile for others, and gets across each side of the issue better. Confrontations between individuals need to be taken elsewhere.
Let's take a break. This thread is locked.
12-11-2010, 06:35 AM
#45
Senior Member
RE: the rational of trimming
ORIGINAL: flyncajun
Ohh ! sorry Matt, I don`t know where I got Brio from,
Dick ,name me any top pattern competition model with equal wing,fuse area,
I`ll let you believe what you want , no one is going to change your mind. But, there is no one using your methods of (just fly around the pulls if your good enough) at the top of any class in competition.
The wing does the same job in a up line-down line or level flight (common sense) or the elevator trim would need to change when you pulled up (oh wait it does using your methods LOL) even though you use incredible amounts of down thrust to pull it to the belly!
I can back up what I preach (speaking of religion) or some one would have called my hand by now
My methods and designs are out there world wide, have been for 20 years, surly someone could prove me wrong, if I were all wet,
As You have seen many times in my replys to trim help threads ,where you injected your oppinions to rebutt mine , (and they are too many to count) when I told the modeler what to do to fix their particular trim problem, they alway came back and said ''Thank you, you told me exactly what to do and it worked perfectly'' and then others trying what I recomended came back and said, ME TOO! I tried it, it worked, you predicted the problems and fixed it.
like here below!
http://www.rcuniverse.com/forum/m_74...tm.htm#7522813
You always come back and still tell me ''believe what you want but, you have no idea what your talking about'' ,and there is no way what I said could really work!
Remember, I challenged you to prove me wrong ,and report back if my methods worked or not, you refused to take me up on the offer.Really ,I`m not even sure how you are able to answer so many questions on this list ,You just do a drive-by on just about every subject written!
It`s easy to do a verbal drive-by ,but it`s harder to back up what you believe to be true ,and actually help someone fix their trim problems without a puzzling exercise in mental gynastics ,instead of just plain old common sense!
Tell you what, Tell me the wing area of the airplane your currently flying, the wieght, c/g, downthrust,and wing incidence, I`ll tell you every issue you are having trim wise, where it pulls ,where it tucks, when it tip stalls and nail it on the nose! then I`ll tell you how to fix it!
Thats not religion or faith it`s experiance
Bryan
hebertcompetitiondesigns.com
Ohh ! sorry Matt, I don`t know where I got Brio from,
Dick ,name me any top pattern competition model with equal wing,fuse area,
I`ll let you believe what you want , no one is going to change your mind. But, there is no one using your methods of (just fly around the pulls if your good enough) at the top of any class in competition.
The wing does the same job in a up line-down line or level flight (common sense) or the elevator trim would need to change when you pulled up (oh wait it does using your methods LOL) even though you use incredible amounts of down thrust to pull it to the belly!
I can back up what I preach (speaking of religion) or some one would have called my hand by now
My methods and designs are out there world wide, have been for 20 years, surly someone could prove me wrong, if I were all wet,
As You have seen many times in my replys to trim help threads ,where you injected your oppinions to rebutt mine , (and they are too many to count)
when I told the modeler what to do to fix their particular trim problem, they alway came back and said ''Thank you, you told me exactly what to do and it worked perfectly'' and then others trying what I recomended came back and said, ME TOO! I tried it, it worked, you predicted the problems and fixed it.like here below!
http://www.rcuniverse.com/forum/m_74...tm.htm#7522813
You always come back and still tell me ''believe what you want but, you have no idea what your talking about'' ,and there is no way what I said could really work!
Remember, I challenged you to prove me wrong ,and report back if my methods worked or not, you refused to take me up on the offer.Really ,I`m not even sure how you are able to answer so many questions on this list ,You just do a drive-by on just about every subject written!
It`s easy to do a verbal drive-by ,but it`s harder to back up what you believe to be true ,and actually help someone fix their trim problems without a puzzling exercise in mental gynastics ,instead of just plain old common sense!
Tell you what, Tell me the wing area of the airplane your currently flying, the wieght, c/g, downthrust,and wing incidence, I`ll tell you every issue you are having trim wise, where it pulls ,where it tucks, when it tip stalls and nail it on the nose! then I`ll tell you how to fix it!
Thats not religion or faith it`s experiance
Bryan
hebertcompetitiondesigns.com
FWIWMy Temptress design last season was fitted with the SAP180HP gasoline engine which increased weight in the nose by about 4 ozs over the Webra I was using. That basically increased my static margin about 5%. As Bryan has stated time and again, in most cases planes will beneft when bringing cg forward....the airplane locked better. Inverted flight was slightly compromised over what I was used but after flying like that all season, I preferred the new flight envelope overall. Bottom line, my plane was well trimmed before but now it felt a little better using one of Bryan's ideas.
12-11-2010, 08:46 AM
#46
RE: the rational of trimming
Hey Matt I was thinking you had a Brio flying last year my bad!
You have been with me all along with this stuff, and you have the experiance to back it up as well.
Competition is tough any advantage,trick,revelation seems BIG when the scores are so close so as pattern fliers,we tend to either keep it to our selves or, tell everyone we know
After helping countless fliers trim their pattern and IMAC airplanes from around the World, I had to learn how to ask the right questions, or I would give them the wrong answers because they usually gave me half truths.
It Amazed me how many times I would get a question about a trim problem where they were hidding a pet (feel or habit ) I had to learn to ask setup and get the airplane flying right ,then it was up to the pilot to actually increase his skill to handle the knowledge.
Say like < some guys like to fly around carrying a little down trim in the airplane/ transmitter then keep a light up touch on the up elevator stick while upright, this way when they roll inverted they need no, to very little down elevator. This always sounds like a good idea, But this effects knife edge flight, up, and down lines. the main reason they do this? well ,ussually they are not proficient with the rudder, and don`t understand the difference between airplane set up and radio setup there is a big difference between the two, and is where a lot of the problems stem from.
The airplane is set up very tail heavy so it rolls to inverted without any input except ailerons once you get there, just touch the down stick and your done! Nope, this is the Genesis of 95 % of all trim issues with any airplane.
You will alway require some rudder to roll to ,or through the knife edge ,this is the biggest shortcut, Fable ,about a pattern airplane ,that you should be able to fly it inverted ,or roll to it with no input and this myth usually is the start of all missconceptions on the trimming journey. This missconception goes all the way to next classes with them, and becomes part of how they learn to fly and adapt their skills to it.
Most guys starting in pattern start at the club level and have the club pro, or another new guy in pattern help to get their flight and setup ironed out. they call foe each other ,travel help each other in many ways,and generally accept each others habbits so the information they recieve is usually a lateral step,by that I mean if the loop is round ,the line was straight, or the landing centered they get a "atta boy" from equal or lower skill level, and think they are flying good patterns.They may even get a few trophies here and there.
"
This develops into bad habbits over time. A snow ball of improper setups creating bad habbits or "pet habbits".Then when they get actuall expert advise they can`t use it, or they go back to their old habits because it cannot mesh with the setup they have become used to.
This is usually around the time they are required to do four point rolls ,and snaps in the Advanced class in pattern.
The setup they have become used to, cannot perform the maneuver correctly. But,Their scores start falling away they start looking for answers and then they learn they have to continue trying to decieve themselves or, begin to chip away at the bad habbits they have accumulated for the last 3 years.
Some even take it all the way up to FAI and learn how to become very clever with the radio to fly around the bad habits they hold dearly.
I know this is long Winded But it`s an effort for guys to understand , Expert advise is not always liked or recieved well.
Like the old preacher says, when you throw a stick in the back yard the dog that yelps is the one you hit
I play the Guitar when I go to my local Expert and try to play his Guitar I can`t handle it because my tecnique is not good enough.
Can I play ,Yup , but not at his level, if I ask advise on how to play the way he does, sometime I don`t like what he tells me.
Why, because I would have to relearn all my bad habbits and start from scratch, I`m not willing to do that LOL so ,I continue to amuse myself with my bad habbits and some guys I play with think I play really nice and pat me on the back LOL ,,you see what I mean now.
This is the most important tip I can give ,Airplane set up and Radio set up are two different things , you have to set the airplane up to fly all angles as perfect as posible first, when the airplane performs the best you can get it to, on all up lines ,down lines , and both knife edges ,then Set the airplane up to do the hardest maneuver in the pattern (usually snaps .whole other subject) then set the radio up to fly the airplane ,,do not dumb the radio or airplane down to your skill ,, bump your skill up to the level required to fly your class.
Doing this ,you will never have to relearn,or go back to the drawing board with your setup you just keep refining your skills and getting better because now you don`t need to relearn how to overcome old habbits with new ones.
and by all means seek expert advise!
Bryan
You have been with me all along with this stuff, and you have the experiance to back it up as well.
Competition is tough any advantage,trick,revelation seems BIG when the scores are so close so as pattern fliers,we tend to either keep it to our selves or, tell everyone we know
After helping countless fliers trim their pattern and IMAC airplanes from around the World, I had to learn how to ask the right questions, or I would give them the wrong answers because they usually gave me half truths.
It Amazed me how many times I would get a question about a trim problem where they were hidding a pet (feel or habit ) I had to learn to ask setup and get the airplane flying right ,then it was up to the pilot to actually increase his skill to handle the knowledge.
Say like < some guys like to fly around carrying a little down trim in the airplane/ transmitter then keep a light up touch on the up elevator stick while upright, this way when they roll inverted they need no, to very little down elevator. This always sounds like a good idea, But this effects knife edge flight, up, and down lines. the main reason they do this? well ,ussually they are not proficient with the rudder, and don`t understand the difference between airplane set up and radio setup there is a big difference between the two, and is where a lot of the problems stem from.
The airplane is set up very tail heavy so it rolls to inverted without any input except ailerons once you get there, just touch the down stick and your done! Nope, this is the Genesis of 95 % of all trim issues with any airplane.
You will alway require some rudder to roll to ,or through the knife edge ,this is the biggest shortcut, Fable ,about a pattern airplane ,that you should be able to fly it inverted ,or roll to it with no input and this myth usually is the start of all missconceptions on the trimming journey. This missconception goes all the way to next classes with them, and becomes part of how they learn to fly and adapt their skills to it.
Most guys starting in pattern start at the club level and have the club pro, or another new guy in pattern help to get their flight and setup ironed out. they call foe each other ,travel help each other in many ways,and generally accept each others habbits so the information they recieve is usually a lateral step,by that I mean if the loop is round ,the line was straight, or the landing centered they get a "atta boy" from equal or lower skill level, and think they are flying good patterns.They may even get a few trophies here and there.
"
This develops into bad habbits over time. A snow ball of improper setups creating bad habbits or "pet habbits".Then when they get actuall expert advise they can`t use it, or they go back to their old habits because it cannot mesh with the setup they have become used to.
This is usually around the time they are required to do four point rolls ,and snaps in the Advanced class in pattern.
The setup they have become used to, cannot perform the maneuver correctly. But,Their scores start falling away they start looking for answers and then they learn they have to continue trying to decieve themselves or, begin to chip away at the bad habbits they have accumulated for the last 3 years.
Some even take it all the way up to FAI and learn how to become very clever with the radio to fly around the bad habits they hold dearly.
I know this is long Winded But it`s an effort for guys to understand , Expert advise is not always liked or recieved well.
Like the old preacher says, when you throw a stick in the back yard the dog that yelps is the one you hit
I play the Guitar when I go to my local Expert and try to play his Guitar I can`t handle it because my tecnique is not good enough.
Can I play ,Yup , but not at his level, if I ask advise on how to play the way he does, sometime I don`t like what he tells me.
Why, because I would have to relearn all my bad habbits and start from scratch, I`m not willing to do that LOL so ,I continue to amuse myself with my bad habbits and some guys I play with think I play really nice and pat me on the back LOL ,,you see what I mean now.
This is the most important tip I can give ,Airplane set up and Radio set up are two different things , you have to set the airplane up to fly all angles as perfect as posible first, when the airplane performs the best you can get it to, on all up lines ,down lines , and both knife edges ,then Set the airplane up to do the hardest maneuver in the pattern (usually snaps .whole other subject) then set the radio up to fly the airplane ,,do not dumb the radio or airplane down to your skill ,, bump your skill up to the level required to fly your class.
Doing this ,you will never have to relearn,or go back to the drawing board with your setup you just keep refining your skills and getting better because now you don`t need to relearn how to overcome old habbits with new ones.
and by all means seek expert advise!
Bryan
12-11-2010, 10:48 AM
#49
Senior Member
Join Date: Nov 2006
Location: Denham Springs, LA
Posts: 187
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RE: the rational of trimming
ORIGINAL: flyncajun
you bet!
But the fuse area is still not as big as the wings
I trim um all the time
Bryan
you bet!
But the fuse area is still not as big as the wings
I trim um all the time
Bryan
I understand the arguments; some people love to argue. You and I used to have many engineering discussions, too, based upon my own engineering education: but what I do not understand, is why these EXPERTS are so locked into their own thinking that they refuse to consider the possibility of an improvement. Winning requires innovative thinking, on top of effort. Ten hours a week practise? I do that much on a Saturday alone, during contest season. Before the NATS each year I usually burn a case and a half a week. That's almost 50 flights per week. So why, pray tell, would I neglect to try any and EVERY thing to improve my setup? If my plane has any unwanted tendency, I try to fix it. Period. If I was an all knowing aeronautical engineer, then it seems there would be no problems or mixes in the first place!
Ultimately, it boils down to performance; if there is a deficiency in the flight envelope, there must be something yet to be learned. ANY good scientist would be open to new data; but not here. We've invented the wheel, by God, and it can't be made better. It's physics. We've got it all figured out. Don't confuse us with facts, you are not credible because you don't talk like an MIT professor.
Losers! I made a simple challenge, which I will repeat; anyone, come to Baton Rouge and fly one of my Shindens. Maybe I'd meet you part way if it seems we'll be having fun! Anybody that believes no-mix is impossible, come see me to collect some empirical data. Maybe I'll wind up getting a lesson, maybe you will. One of us would certainly gain from the exchange, and share with others. But if you want a better airplane, you MUST be open to new ideas; not that this trimming method is exactly new; you've been doing it a long time but people just do not want to let go of their antiquated concepts.
One thought before I go; that MIT professor...... was he stupid before he got his degrees, or was he merely un-degreed? Was he like the scarecrow of Oz, gaining ultimate knowledge the moment the parchment hit his hand, or was the intellect there all along? They love to bag on you for not having a sheepskin, because it's all they have. I do not consider myself a great pilot, yet, I have had moderately good success using your designs and trimming methods (and coaching!) That should speak for itself. And I do have a fairly high degree of education. I have found your experience to be a better teacher.
Brian Clemmons
D6 Advanced Champion 2010
3rd Place Advanced US NATS 2010
12-11-2010, 10:55 AM
#50
RE: the rational of trimming
take total side area (fin rudder /landing gear/fuselage) vs total projected wing panel area.
compare areas.
If you include center section of wing (fuselage area) then the ratio will be quite a bit different
If you assume the fuselage does not contribute lift - then do not include .
compare areas.
If you include center section of wing (fuselage area) then the ratio will be quite a bit different
If you assume the fuselage does not contribute lift - then do not include .