Aileron to Rudder Mixing..
10-04-2005, 11:15 AM
#1
Aileron to Rudder Mixing..
I was just reading MA News and it has an article on radio mixing n stuff.
In there they have mixing rudder to ailerons, and I just don't understand this mix. I've heard many people before mention it but I can't see how it helps.
When I fly I bank the plane with aileron, center the ailerons, pull through the turn and then roll out with aileron. With the mix you would not have rudder while in the turn so how is the mix helpful? You'd have mixed rudder when rolling in and out but not during the turn.
When I was flying full scale you had rudder constantly through the turn.
Am I missing something?
In there they have mixing rudder to ailerons, and I just don't understand this mix. I've heard many people before mention it but I can't see how it helps.
When I fly I bank the plane with aileron, center the ailerons, pull through the turn and then roll out with aileron. With the mix you would not have rudder while in the turn so how is the mix helpful? You'd have mixed rudder when rolling in and out but not during the turn.
When I was flying full scale you had rudder constantly through the turn.
Am I missing something?
10-04-2005, 12:28 PM
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RE: Aileron to Rudder Mixing..
Aileron to Rudder is mostly used on planes like the J-3 Piper Cub which has the "barn-door" ailerons at the very tip of the wings. This causes adverse yaw, and really i you just use aileron on a Piper or similar plane, then it really doesn't even look good in the turn.
Now in the thread title you said aileron to rudder mixing, and in your post you say rudder to aileron. With the rudder to aileron, you can use this when you do a knife edge. With right rudder in a knife edge, you might have rolling to the right. You can mix in a little down right, and up left aileron to mix out this and you just have a strait knife edge where you don't have to do that much stick movements.
Hope this helps
~Michael~
Now in the thread title you said aileron to rudder mixing, and in your post you say rudder to aileron. With the rudder to aileron, you can use this when you do a knife edge. With right rudder in a knife edge, you might have rolling to the right. You can mix in a little down right, and up left aileron to mix out this and you just have a strait knife edge where you don't have to do that much stick movements.
Hope this helps
~Michael~
10-04-2005, 01:02 PM
#3
RE: Aileron to Rudder Mixing..
I meant aileron to rudder, I can see how rudder to aileron is helpful in KE just not how aileron to rudder is helpful for turns. I've never flown a piper cub so I've never experienced adverse yaw on one. IF that's what it's used for mainly that at least makes sense.
10-04-2005, 02:11 PM
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RE: Aileron to Rudder Mixing..
Do a turn with aileron and elevator and you tend to see the plane drift to the ground as you make the turn.
You need to use the rudder to keep it at a constant altitude. With this said, some people just fly the turn, others use a mix to add some rudder with aileron so that the plane doesn't drift down.
You need to use the rudder to keep it at a constant altitude. With this said, some people just fly the turn, others use a mix to add some rudder with aileron so that the plane doesn't drift down.
10-04-2005, 03:03 PM
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RE: Aileron to Rudder Mixing..
Exactly. Ditto to that. Look for a Piper next time you go to the field. Go to the pilot and ask if he will do a turn without using rudder (that is if he doesn't have a mix for aileron to rudder and he manually had to use rudder on the turn). Then ask to do one with rudder and you will see a big difference.
Just like Geistware said, just a turn with aileron and elevator will make the plane usually start toward the ground. That's just how I had my most recent crash with my Funtana. Took the turn too low and too fast and I lost altitude too quick. I usually use rudder, but didn't that time.
The use of rudder with ailerons and elevator make for a more cordinated turn. This is especially important for a scale plane: Cessna, P-51, Corsair. Anything like that.
You can choose to use rudder or not. Usually, the left stick for rudder is forgotten after someone learns to fly.
~Michael~
Just like Geistware said, just a turn with aileron and elevator will make the plane usually start toward the ground. That's just how I had my most recent crash with my Funtana. Took the turn too low and too fast and I lost altitude too quick. I usually use rudder, but didn't that time.
The use of rudder with ailerons and elevator make for a more cordinated turn. This is especially important for a scale plane: Cessna, P-51, Corsair. Anything like that.
You can choose to use rudder or not. Usually, the left stick for rudder is forgotten after someone learns to fly.
~Michael~
10-04-2005, 03:31 PM
#6
RE: Aileron to Rudder Mixing..
Another use of aileron-rudder mixing is on 3-channel planes.
When I first fly a 3-channel plane, I usually end up embarrassing myself by trying to steer with the wrong hand. Usually all steering is on the right stick and there is no left-right control on the left (usually rudder) stick. However, if you plug the rudder servo into the normal rudder channel, then set aileron rudder mixing on and to 100%, both sticks will move the rudder. I can steer on take off and taxi with my left hand and in the air with the right.
When I first fly a 3-channel plane, I usually end up embarrassing myself by trying to steer with the wrong hand. Usually all steering is on the right stick and there is no left-right control on the left (usually rudder) stick. However, if you plug the rudder servo into the normal rudder channel, then set aileron rudder mixing on and to 100%, both sticks will move the rudder. I can steer on take off and taxi with my left hand and in the air with the right.
10-04-2005, 03:31 PM
#7
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RE: Aileron to Rudder Mixing..
ORIGINAL: Geistware
Do a turn with aileron and elevator and you tend to see the plane drift to the ground as you make the turn.
You need to use the rudder to keep it at a constant altitude. With this said, some people just fly the turn, others use a mix to add some rudder with aileron so that the plane doesn't drift down.
Do a turn with aileron and elevator and you tend to see the plane drift to the ground as you make the turn.
You need to use the rudder to keep it at a constant altitude. With this said, some people just fly the turn, others use a mix to add some rudder with aileron so that the plane doesn't drift down.
In ANY turn, once the turn's established, no aileron or rudder should be used. Only elevator to maintain altitude. If the airplane tends to roll in or roll out of the turn, then some aileron may be needed to hold the bank, but usually not much at all. From what I've seen of a number of modelers, they roll into a steep bank, neutralize ailerons, add enough elevator to do a half loop on its side, and then roll out when the planes pointed more or less in the direction they want to go. True coordinated flight isn't often seen. This tendency is reduced when the model is in the landing phase. Then, the banks usually don't exceed 30-45 degrees.
In a model, you use rudder mixed with ailerons to help roll. With many large models, Cub-types, and large gliders, there's enough adverse yaw that the model doesn't roll well at all. You need to add rudder along with the ailerons to effect a good roll-in or roll-out of the turn. You can do this with your rudder thumb, or add a mixer. Use right rudder when you apply right aileron, and vice-versa.
10-04-2005, 06:06 PM
#8
RE: Aileron to Rudder Mixing..
These are some interesting replys. In full scale in a coordinated turn you need to HOLD rudder throughout the turn, not just entering the turn otherwise the tail drags through the turn. In my modeling experience I have noticed the same. You can see a pilot that makes coordinated turns and the ones that just bank and yank. This is why I'm wondering what good it does to have the mix in because when you center the ailerons in the turn you loose the rudder you had mixed in to provide a coordinated turn.
You guys speakin of adverse yaw are you saying you put in left aileron and the plane yaws to the right? So if that's the case you have right rudder mixed in with left aileron? Opposite of what you would do in say a Piper Warrior (since that's my full scale experience)? I do understand that on some models you may need the rudder and the ailerons to assist in rolling the airplane.
Basically this mix is intended to assist aircraft that require both aileron and rudder for rolling the aircraft.
The mix is not intended to provide coordinated flight.
Bax, I don't think the statement "In ANY turn, once the turn's extablished, no aileron or rudder should be used." is accurate, based on my full scale experience.
You guys speakin of adverse yaw are you saying you put in left aileron and the plane yaws to the right? So if that's the case you have right rudder mixed in with left aileron? Opposite of what you would do in say a Piper Warrior (since that's my full scale experience)? I do understand that on some models you may need the rudder and the ailerons to assist in rolling the airplane.
Basically this mix is intended to assist aircraft that require both aileron and rudder for rolling the aircraft.
The mix is not intended to provide coordinated flight.
Bax, I don't think the statement "In ANY turn, once the turn's extablished, no aileron or rudder should be used." is accurate, based on my full scale experience.
10-05-2005, 10:21 AM
#9
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RE: Aileron to Rudder Mixing..
ORIGINAL: camss69
Bax, I don't think the statement "In ANY turn, once the turn's extablished, no aileron or rudder should be used." is accurate, based on my full scale experience.
Bax, I don't think the statement "In ANY turn, once the turn's extablished, no aileron or rudder should be used." is accurate, based on my full scale experience.
I learned to fly in a T-Craft BC-12D, PA-11, and 7ECA Citabria. Many modern aircraft are "feet on the floor", where you almost never need to use rudder with ailerons.
10-05-2005, 12:50 PM
#11
RE: Aileron to Rudder Mixing..
ORIGINAL: JohnBuckner
camss69 This quoted statement by Bax above is indeed quite accurate and most applicable to this discussion. Adverse yaw is the reason full scale pilots will always (with the exception of a deliberate slip) use both the rudder and aileron together upon a turn entry and upon establishing a turn will return both the aileron and rudder to near neutral. Its at this point that the rudder become a trim device and used just as neccessary to trim the vertical axis during the turn, how many time have you heard your full scale instructor admonish "step on the ball". I'am willing to bet three burned out glow plugs aginst a stale glazed donut that this phrase is burned into your head. Holding constant pro turn rudder during the turn will only result in a skid with the decidedly uncomfortable feeling that your butt is gonna fall outta the airplane.
Now for instance most of the airplanes listed above by Bax do suffer from substancially more adverse yaw than more modern general aviation airplanes because of all sorts of aerodynamic trickery used in later craft. Things like properly designed ailerons that include differential and yes even aileron to rudder mix. Hows that for a shock, its a good bet that most of the aircraft you have flown do include "aileron 'to' rudder mix". Most modern single engine Cessna's and all of the entire PA-28 piper series do indeed include this mix. It is done mechanically with springs and such. Try trucking down the taxiway with oh say a PA-28 any flavor and take your hand off the column and watch it when making sharp turns with the pedals. These mix's are sloppy and not very noticible but indeed is common with many full scale.
Now lets talk of the need for this mix. The aircraft that will benefit the most from this (both full scale and model) are High wing aircraft with big barn door ailerons (as already mentioned in this thread) low wing and midwing are affected the least by the yaw. Most low wing RC craft there simply is not that much need to coordinate rudder with the ailerons (there are always exceptions of course).
Go to an RC field any time and watch the high wing airplanes when being poorly flown will look like drunken sailor when making a climbing turn to the left. The reason for this is its the worst case senario in this climb and the combined effects of adverse yaw and 'P" factor in the sustained climb. Most highwing models can benefit from a small proportion of aileron to rudder mix for these reasons. It is nothing that proper use of rudder in flight won,t handle but in reality most RC pilots do not do this at all times that it may be needed.
The mix that Geistware is talking of is for an entirely differant and opposite purpose of the common usage for aileron to rudder mix. In fact this mix applies opposite rudder than the aileron. This is essentially providing pitch trim with the rudder when the aircraft is in knife edge flight.
There are many mix's used for all sorts of fine tuning various manuvers and such but the Aileron to rudder is the most basic of all. Not needed by every airplane but of some benefit to others. My four engine airplane (which have large barn door ailerons would loose even the simple ability to turn substancially if the mix were not used.
I,am no expert but the assesments above are based on almost a lifetime of teaching folks to fly full scale aircraft (fixed and Rotor) and still at it almost full time now in my wheelchair teaching RC.
John
ORIGINAL: Bax
Hmmm. I was taught that you used rudder to prevent adverse yaw when applying ailerons. When the ailerons were neutral, the rudder would be neutral. You do have to watch the ball and keep it centered with the rudder pedals, but usually don't "hold" rudder in a bank.
I learned to fly in a T-Craft BC-12D, PA-11, and 7ECA Citabria. Many modern aircraft are "feet on the floor", where you almost never need to use rudder with ailerons.
Hmmm. I was taught that you used rudder to prevent adverse yaw when applying ailerons. When the ailerons were neutral, the rudder would be neutral. You do have to watch the ball and keep it centered with the rudder pedals, but usually don't "hold" rudder in a bank.
I learned to fly in a T-Craft BC-12D, PA-11, and 7ECA Citabria. Many modern aircraft are "feet on the floor", where you almost never need to use rudder with ailerons.
camss69 This quoted statement by Bax above is indeed quite accurate and most applicable to this discussion. Adverse yaw is the reason full scale pilots will always (with the exception of a deliberate slip) use both the rudder and aileron together upon a turn entry and upon establishing a turn will return both the aileron and rudder to near neutral. Its at this point that the rudder become a trim device and used just as neccessary to trim the vertical axis during the turn, how many time have you heard your full scale instructor admonish "step on the ball". I'am willing to bet three burned out glow plugs aginst a stale glazed donut that this phrase is burned into your head. Holding constant pro turn rudder during the turn will only result in a skid with the decidedly uncomfortable feeling that your butt is gonna fall outta the airplane.
Now for instance most of the airplanes listed above by Bax do suffer from substancially more adverse yaw than more modern general aviation airplanes because of all sorts of aerodynamic trickery used in later craft. Things like properly designed ailerons that include differential and yes even aileron to rudder mix. Hows that for a shock, its a good bet that most of the aircraft you have flown do include "aileron 'to' rudder mix". Most modern single engine Cessna's and all of the entire PA-28 piper series do indeed include this mix. It is done mechanically with springs and such. Try trucking down the taxiway with oh say a PA-28 any flavor and take your hand off the column and watch it when making sharp turns with the pedals. These mix's are sloppy and not very noticible but indeed is common with many full scale.
Now lets talk of the need for this mix. The aircraft that will benefit the most from this (both full scale and model) are High wing aircraft with big barn door ailerons (as already mentioned in this thread) low wing and midwing are affected the least by the yaw. Most low wing RC craft there simply is not that much need to coordinate rudder with the ailerons (there are always exceptions of course).
Go to an RC field any time and watch the high wing airplanes when being poorly flown will look like drunken sailor when making a climbing turn to the left. The reason for this is its the worst case senario in this climb and the combined effects of adverse yaw and 'P" factor in the sustained climb. Most highwing models can benefit from a small proportion of aileron to rudder mix for these reasons. It is nothing that proper use of rudder in flight won,t handle but in reality most RC pilots do not do this at all times that it may be needed.
The mix that Geistware is talking of is for an entirely differant and opposite purpose of the common usage for aileron to rudder mix. In fact this mix applies opposite rudder than the aileron. This is essentially providing pitch trim with the rudder when the aircraft is in knife edge flight.
There are many mix's used for all sorts of fine tuning various manuvers and such but the Aileron to rudder is the most basic of all. Not needed by every airplane but of some benefit to others. My four engine airplane (which have large barn door ailerons would loose even the simple ability to turn substancially if the mix were not used.
I,am no expert but the assesments above are based on almost a lifetime of teaching folks to fly full scale aircraft (fixed and Rotor) and still at it almost full time now in my wheelchair teaching RC.
John
10-05-2005, 01:48 PM
#12
RE: Aileron to Rudder Mixing..
Wow that's all really good stuff, I've been wondering about this mix for some time, mainly why people would use it.
I obviously stand corrected on my constant rudder in a turn theory.
Learn something new everyday..
I obviously stand corrected on my constant rudder in a turn theory.
Learn something new everyday..
10-05-2005, 06:26 PM
#13
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RE: Aileron to Rudder Mixing..
OK, I went to try it and when I enter a banks at 60-90 degrees and pull through a turn, I have to use rudder to hold the altitude. I tried it several times. The only way I see that this would not be true is if the CG was such that the center of lift in a turn is also the CG point. I try to keep my CG ahead of the center of lift.
ORIGINAL: Bax
Huh??? (Oops. Impolite.) I beg to differ.
In ANY turn, once the turn's established, no aileron or rudder should be used. Only elevator to maintain altitude. If the airplane tends to roll in or roll out of the turn, then some aileron may be needed to hold the bank, but usually not much at all. From what I've seen of a number of modelers, they roll into a steep bank, neutralize ailerons, add enough elevator to do a half loop on its side, and then roll out when the planes pointed more or less in the direction they want to go. True coordinated flight isn't often seen. This tendency is reduced when the model is in the landing phase. Then, the banks usually don't exceed 30-45 degrees.
In a model, you use rudder mixed with ailerons to help roll. With many large models, Cub-types, and large gliders, there's enough adverse yaw that the model doesn't roll well at all. You need to add rudder along with the ailerons to effect a good roll-in or roll-out of the turn. You can do this with your rudder thumb, or add a mixer. Use right rudder when you apply right aileron, and vice-versa.
Huh??? (Oops. Impolite.) I beg to differ.
In ANY turn, once the turn's established, no aileron or rudder should be used. Only elevator to maintain altitude. If the airplane tends to roll in or roll out of the turn, then some aileron may be needed to hold the bank, but usually not much at all. From what I've seen of a number of modelers, they roll into a steep bank, neutralize ailerons, add enough elevator to do a half loop on its side, and then roll out when the planes pointed more or less in the direction they want to go. True coordinated flight isn't often seen. This tendency is reduced when the model is in the landing phase. Then, the banks usually don't exceed 30-45 degrees.
In a model, you use rudder mixed with ailerons to help roll. With many large models, Cub-types, and large gliders, there's enough adverse yaw that the model doesn't roll well at all. You need to add rudder along with the ailerons to effect a good roll-in or roll-out of the turn. You can do this with your rudder thumb, or add a mixer. Use right rudder when you apply right aileron, and vice-versa.
10-05-2005, 07:41 PM
#14
RE: Aileron to Rudder Mixing..
Geistware I hope you do not think I was disputing the point you are making which I was not. I was trying to explain to camss69 the differance between rudder use (and/or aileron rudder mix's) in a normal steady state medium turns (perhaps up to say 60, 70 degrees) and the effects of AY along with the use of mixing to aid in the character of the turn. I quite agree that in many airplanes at extreme banks there is indeed the effect you describe. Effectively we are now using rudder for pitch control and top rudder for some aircraft can be needed since we are now flying on the fuselage momentarily.
In very high speed airplanes, pylon racers for instance where all on course turns are to the left this effect can be minimised with small preset rudder trim applications. Another method to eliminate this pitch out on the hard pull in a vertical bank (I am not talking sustained knife edge flight on a straight track) is the adjustment of the CG to the rear slightly or a moving slightly forward in the case of a pitch up on the hard pull in a vertical bank. I once tried an aileron to rudder mix on a pair of small Nelson powered Me 109's I built for my team mate and I for warbird pylon racing. Since all turns are to the left I mixed a small proportion of right rudder with left aileron. This to combat the dip out on pulling hard vertical bank 'G'. Did work after a fashion but presented some problems later i.e. landing. Most of the warbirds are not particularly great flyers and this mix was abandoned. Quite unlike AMA rulebook pylon ships, Q-500 (428) and Q-40's (422) these ships exhibit much better manners and in the couse of a race these will when well flown may only be changing bank from around 60 to 90 degrees for the entire flight save landing and T/O.
Camss69
When referring to mixs the first control referanced is always the primary (the one you actually imput a change) and the second is the mixed second control. For your edification her is a good example of two totally different mixs sometimes used but are frequently much confused. They are Elevator to Flap mix and the second is Flap to Elevator mix. Lets look at the first, Elevator to flap mix. This involves mixing ailerons so that roll control will always be present but also allow both ailierons to to reflex up as well as down (this can be referred to spoilerons or flaperons. Now the flaps are mixed with the elevator (remember elevator is primary since it is Elev to Flap). The purpose is to cause the flaps to go down when the elevator is commanded up and vice versa. This will effect much tighter loops both inside and outside.
Now lets examine the second similar mix, Flap to Elevator. Very similar sounding but for an entirely different purpose. With this mix the flap control is primary and effects a preset change in the elevator. In english the purpose is to change pitch trim to the predetermined position when flaps are actuated. Most airplanes will exhibit a pitch trim change as you know when you put your flaps down.
John
In very high speed airplanes, pylon racers for instance where all on course turns are to the left this effect can be minimised with small preset rudder trim applications. Another method to eliminate this pitch out on the hard pull in a vertical bank (I am not talking sustained knife edge flight on a straight track) is the adjustment of the CG to the rear slightly or a moving slightly forward in the case of a pitch up on the hard pull in a vertical bank. I once tried an aileron to rudder mix on a pair of small Nelson powered Me 109's I built for my team mate and I for warbird pylon racing. Since all turns are to the left I mixed a small proportion of right rudder with left aileron. This to combat the dip out on pulling hard vertical bank 'G'. Did work after a fashion but presented some problems later i.e. landing. Most of the warbirds are not particularly great flyers and this mix was abandoned. Quite unlike AMA rulebook pylon ships, Q-500 (428) and Q-40's (422) these ships exhibit much better manners and in the couse of a race these will when well flown may only be changing bank from around 60 to 90 degrees for the entire flight save landing and T/O.
Camss69
When referring to mixs the first control referanced is always the primary (the one you actually imput a change) and the second is the mixed second control. For your edification her is a good example of two totally different mixs sometimes used but are frequently much confused. They are Elevator to Flap mix and the second is Flap to Elevator mix. Lets look at the first, Elevator to flap mix. This involves mixing ailerons so that roll control will always be present but also allow both ailierons to to reflex up as well as down (this can be referred to spoilerons or flaperons. Now the flaps are mixed with the elevator (remember elevator is primary since it is Elev to Flap). The purpose is to cause the flaps to go down when the elevator is commanded up and vice versa. This will effect much tighter loops both inside and outside.
Now lets examine the second similar mix, Flap to Elevator. Very similar sounding but for an entirely different purpose. With this mix the flap control is primary and effects a preset change in the elevator. In english the purpose is to change pitch trim to the predetermined position when flaps are actuated. Most airplanes will exhibit a pitch trim change as you know when you put your flaps down.
John
10-05-2005, 08:13 PM
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RE: Aileron to Rudder Mixing..
Wow, this got really interesting. Lots of post and very credible and right answers......
Like was stated, you DO learn something new everyday!! I just learned alot from these last couple posts......
~Michael~
Like was stated, you DO learn something new everyday!! I just learned alot from these last couple posts......
~Michael~
