Knife Edge Switch
 

I have a bipe which requires alot of mixing to get rid of pitch an roll in Knife edge..........Should you put this on a switch solely OR
could you just fly the plane with the mix on all the time.Would you gain a pure yaw response from the plane all the time ??????????
Like that up elevator you'd get steering the plane on take off.

Knife Edge Switch
 

I depends on how much elevator and in which direction you need. If it pulls toward the landing gear that is sorta normal. Try a flat turn just using rudder. If it also tends to drop the nose then you can program in some up elevator with the rudder. After programming in some up elevator in my DP 330L to get it to knife edge in a straight line I tried a flat turn. It doesn't tend to drop the nose any more. We tried the same thing on a Sig Sukoi and it didn't work as well. You'll have to try it. FWIW. I needed 2% more on one side of the rudder than the other.

Knife Edge Switch
 

Programming is not a problem.Its whether to leave it on all the time or connect to a switch when you fly knife.......seems like it would just cause a nice yaw instead of the mess it normally creates without mix,,,,,,Is there a down side to leaving it on

Knife Edge Switch
 

bill,

i fly most of my planes with KE mix always on. Not a problem at all even in stall turns...very small correction is need so i dont bother to keep the mix on a switch.

(I dont need too much mix on the planes I currently have)

Knife Edge Switch
 

You will find that leaving the mix on will make elevators and harriers more difficult especially if you need to mix aileron. Bipes tend to roll as well as pitch with rudder input and you do not want aileron input when you are steering with the rudder at high alpha. This is however just my personal opinion based on my experience. :^)

Knife Edge Switch
 

I have a switch for landing mode or flying. During landing mode, I have my KE and fast idle (plus a few others) turned off. You may be able to use something like this. I think that the KE mix should be on for all flying.

Knife Edge Switch
 

Wouldn't this prevent the roll coupling even at a low airpeed and induce a true yaw.with rudder input...This is a problem with bipes in a flat turn....which i consider knife edge in a horizontal plane....

Of course the side load of wind against the fuse is not as pronounced .........

Seems like if you had the plane flying in true axis control inputs ...everything would fly better........

I fly IMAC type stuff..btw

thought about this myself
 

I've been thinking about this alot myself recently, as I have a UCanDo3D that has some severe rudder coupling. I personally feel that the mix can be left on for any forward flight and normal (flying on the wing) aerobatic maneuvers, but I agree with OUTCAST that it can cause problems in high alpha maneuvers like a harrier, and also in a hover when all you want is a blast of prop wash to give you rudder pitch but with the mix on it also gives you a little unwanted elevator that you would have to correct.
This is my feeling for an airplane that has severe coupling issues, like the original question stated. If it were something more along the lines of say an Edge that doesn't couple very bad, I would leave it on all the time no matter the situation.

Knife Edge Switch
 

During a harrier or elevator forward velocity is very slow if at all, and the ailerons are only used to keep the airframe level. Since the amount of roll couple is proportionate to the amount of side loading, at no velocity there is no side load, however large amounts of rudder are needed to maintain directional control. You really don't want the aileron input when upright at minimum airspeed. And if elevator mix is used it will make it more difficult to hover as every yaw input will induce a pitch change, at least thats what my two remaining brain cells think. :^)

Knife Edge Switch
 

CHEATERS!!! I never use any mixes for that stuff!! or gyros ; )

Knife Edge Switch
 

3dbatixkid, every single pilot, with no exceptions ,at last years TOC used mixes. It would be hard to classify them as cheaters.

Knife Edge Switch
 

Sorry, but I agree with 3dbatixkid. Use the brain in your head instead of the one in your transmitter. It will make you a better flier IMHO. If your plane pitches toward the landing gear during a KE, hold a little up elevator. Is that so difficult? Do you use special mixing for a cross-wind landing, or do you manually feed in some slip? You guys will spend hours programming the exact amount of mixing into your transmitters, and then learn to fly at just the right speed so the mix works, but you won't bother to just manually feed in the correction! No, that takes thinking and coordination. Too much trouble.

Here we go again
 

lets not get ridiculous and start another war here, anyone who has ever flown competition in the modern age will tell you knife edge mix correction is not cheating. It's a competitive advantage to fully utilize the programming features of your computer radio to correct for a given airframes aerobatic shortcomings. During the Freestyle portion of an IMAC contest, should we not mix spoileron to stop wing rock in harriers and elevators? If you think using a mix somehow shows that you don't have the skill or coordination to fly a maneuver properly, by all means show up at the TOC or F3A world championships and share your views with any flyer there and see what their reaction is. To build on what Minnflyer said, your knife edge mix may have been set up on a day where air density and wind direction may have been different due to weather and temperature changes, so you show up at the contest to totally different conditions, the guys at the top of the leader board are using their brains and slightly correcting to keep their headings spot on. The mix will at the very least get the airplane in the ballpark. Cause you know what, the guy in the pit next to you is doing the same thing, and who wants to show up with one strike already against them? "Precision Aerobatics" takes more then a mix to do properly.
Bottom line, if you don't think using a mix is flying, don't use them, the other guy with arrow straight point rolls and KE loops will be glad to let you hold his 1st place trophy! HAHA! :D

Knife Edge Switch
 

3dbatixkid, then why do you use that fancy Futaba radio? :)

Knife Edge Switch
 

eness76,

Point well made.

Knife Edge Switch
 

I use the 9Z because it has the best resolution, and all of the OTHER functions that I need. It is the smoothest radio I have ever owned. I don't use any mixes though. I can't believe that the TOC guys use mixes!!!! THE CHEATERS!! :) :)

Knife Edge Switch
 

3dbatixkid,
Well technically they're not cheating since the rules allow it.
But I agree with your point of view. Wouldn't it be a hoot to see which top flyers can control their plane with flying skills and not programming skills. That's a contest that would be worth seeing.

If one wants to use programming to play with his "toy", who cares? But it seems to go against the spirit of competition imnsvho :D .

"lets not get ridiculous and start another war here" --- eness76
(but you seem ready to carry it on?!)

Knife Edge Switch
 

What OTHER functions? You move those little sticks....

:)

not carrying on anything
 

nah, I'm not carrying on any kind of war, but I've watched this topic discussed from a distance several times before, so I thought I'd weigh in with my experiences. I've been in or around pattern since I was 8 years old. My family has been into pattern for years before that, long before the advent of computer mixes. We were blessed enough to have one of the worlds top flyers in our club in the late seventies and early eighties so we got to see what talent was all about. This was back long before the days of the aerobatic "box", so the point rolls could be long, and my dad loves to tell the stories about Dave Brown (our current AMA pres) stretching point rolls from one side of the field to the other straight as an arrow. So if you'd love to see today's best use their "flying skills" and not their "programming skills", I doubt it would look much different. The analogy here is much like Paul Bunyon, why use an axe when you can use a chainsaw?
It's really that simple. If you want to learn how to do it without cpu radios, more power too you, it will improve you coordination, I'm not bad mouthing that by any means. That's how I learned, and I can still do a pretty darn good 4 or 8 pointer without any mixes, but it's not illegal, thus it's not cheating, so why not take advantage of the technology. Otherwise I would have never stepped above my old JR Century7 that I used in competition for years.

Knife Edge Switch
 

Well. Lets say I stirred the pot..........Let me also say that I'm not dealing with a pattern plane...Im dealing with a Christian Eagle Biplane.......If you fly an Edge 540, Ex 300, Cap or whatever.... You do not experience the type of coupling I'm speaking of...I'm not talking about holding..what I call a Dab..........Where talking about almost fully cross controlling the airplane......I.m talking about mixing out the huge deflections its takes ...so I can deal with just a dab.........If you've ever flown any Pitts you know what Im talking about.........Not an Ultimate .....Not a Weeks.......
As far as the 3_d concerns....I have none.......
If you're flying a Extra 300 trimmed well....You know that if you add rudder from straight and level you will Yaw /Slide and begin a flat turn......If you add rudder to a PItts...You will get a negative Snap /Spin......Lets try to get back on track........IMO if they wanted the TOC or Masters to be on an even keel.......They'd give everyone the same plane and the same radio..like IROC..What you are able to do with a radio ..is what sells radios....whether you use the features of not..........

Knife Edge Switch
 

I see how it isn't technically cheating......I just think that it isn't needed. I would rater do it with my thumbs, and get my brain to be the CPU that does the mixing.

I think that once you fly the plane a LOT and get used to it....It will become second nature. At least that how it is for me.....

Knife Edge Switch
 

Great topic!! personally i never used mixes untill i flew a plane that a toc guy had set up for a guy using mixes, unbelievable. I had never flown a plane that flew to true, hands off in every attitude!! I feel that the setup is a skill that the top guys use to their advantage, the less work you have to do with the coupling the more you can concentrate on the next menouver and less imputs for the same thing are and advantage. In theory it is cheating but its one of those things that has been introduced and would be near imposible to control. I know some people who have point mixes for rudder to throttle and unbelievable mixes to fix a variety of problems such as bent fuses and strange flight characteristics............ If you cant beat is join it 3dbatixkid I guarentee your flying will improve.

switch
 

Don't leave the switch on all the time. I did this on one of my planes. On take off I had left rudder, right aileron, and full up elevator. I almost lost the plane on take off because it wanted to snap roll.

Knife Edge Switch
 

well said. My original reply also delt with a plane with severe coupling like your Pitts. Sorry to take things off track there, but if I were you, I'd leave the mix on and have at it!

Knife Edge Switch
 

I dont think so much a snap mix were talking about, most of those are set onto a sprung switch but more a flight mix... Would be exciting though!!

Knife Edge Switch
 

Nah, I don't buy it. I don't think I'll ever use the mix. I get no less than 3rd in IMAC at contest, so I think im good. And by the way.....First in free!http://www.scaleaerobatics.org/conte...02/sccmas.html

didn't do soo good at this one in the IMAC though, but overall not bad for the season. This was my worst contest.

Knife Edge Switch
 

This is getting WAYYY off topic but...

Im a teenager as well, I fly F3A and IMAC, I have won comps, I dont think im good, I can fly ;) , CPLR is good, Hyde is good, Briggs is the best but i am light years away from them but I dont think mixing is even slighty a factor in me not being as good as them...lol flying sportsman and also freestyle and doing well is nothing to do with mixing?? I could do a few torque rolls, maybe a few 3d moves and im sure mixing wont probably help me there, thats not what the mixing is helping on, an example: on a vertical upline and a cross wind is pushing the model off vertical, when you put the rudder imput in you dont want to also think, oops I need to put left aileron in as well to conteract the roll couple, its pretty simple really. Do you never think how much easier some of your manouvers will be without holding in that aileron while in knife edge.. Do you fly F3A??? when you start winning F3A then you can say your good. Its fully a personal preference, some people like flying the plane and also flying the planes problems, I still think a properly set up plane would help and i prefer flying the plane. Ill be seeing you in a few years at the F3A world champs, ill show you how to use mixes then :D :D :D :D

Knife Edge Switch
 

All these TOC guys, are good enough to Kick ***** with a basic four channel radio and a Sig cadet.. :p

Knife Edge Switch
 

Here's the facts. Lets say for the sake of this discussion that you and I are equal in talent and we are flying in a TOC. You are flying without mixes and I am using them. Yes we can both do point rolls, yes we can both do harriers, blenders, knife edge and the rest, BUT, since we are of equal talent my plane will do it with less divergence from the flight path and you will loose. I've said this before and I will say it again, everybody who wins consistently in almost every sport uses the cutting edge of technology and it makes no difference whether its archery, formula 1 cars, or the bathing suit in a swim contest. Advantage is advantage and all else being equal advantage will win. As long as its legal people will use it and to keep up so will I. Its not cheating, its just leveling the playing field.

Knife Edge Switch
 

Ok, Let's look at it another way...
You and I enter a scale competition. You bring your scratch built, balsa and ply, fabric and dope covered Aeronca, and I bring my Byron Originals Fiberglass Cessna that has rivets and panel lines etc. molded right into the fiberglass. I win; because my plane, (that I spent 200 hours on) has more detail than your plane (that you spent 2000 hours on).

You're right. It's fair. :rolleyes:

Knife Edge Switch
 

1)Depends on how well I did my rib stitching.
2)We would be in a different class
3)No electronics (the topic here) involved.
I'm not saying you have to use mixes, if you don't want to by all means don't, but when the best, most competitive pilots in the world are you can't call it cheating. :^)

Depends on the plane
 

My brother flies an old Joker pattern plane, no mixing. He brags about how he corrects everything himself, but the fact is, it doesn't need much, partly because it doesn't have the rudder throw to do things like knife edge loops. The UCD 3D has so much coupling, it is almost impossible to knife edge loop it without mixing. I still need to correct elevator and aileron because my speed is not always the same and sometimes the wind is blowing, so I definitely don't view it as cheating. It is just eliminating the bad tendencies of that particular aircraft.

Rick

The switch thing
 

3Dbatixkid, I noticed that you said that you don't think it's necessary. For your plane maybe it isn't, but the original gentleman said his airplane had severe coupling issues, instead of fighting his airplane, he wants to have fun. This whole sport is about having fun not arguing about who is right, cause guess what, WE'RE ALL RIGHT. We're all free to believe and do what we want to. One of my patternships has minimal pitch coupling, I can do point rolls from horizon to horizon on a string with no mix, that's cause it's easy to drag a little elevator. I also have had planes that are so lousy with coupling that no amount of CG or trimming would make them any better, but the magic switch made them look arrow straight. Why fight the airframe when you don't have to? My point to the original gentleman is, if the plane couples pretty bad, set up your mix like you know how, and leave your switch on, then in other attitudes of flight rudder input will yield true (or close to true) yaw.
Another analogy for the attacking, haha, The F22 has fly by wire with multi surface mixing just to keep the thing in the air, the pilots stick movements are giving him multi surface movements,more then just the traditional surfaces deflecting, he is still flying the plane. Food for thought.

Knife Edge Switch
 

All these TOC guys, are good enough to Kick ***** with a basic four channel radio and a Sig cadet.. I agree to disagree
Ive been flying on realflight a model which really I thought was a 3d king, a toc flier took the controls off me and tried to do the same thing but couldn't, this guys currently 5th!! not a great example but I don't think these guys are superhuman, they just fly so much and repeat the same thing so many times it becomes natural.. Also there planes fly pretty much themselves.. Trust me. The skill comes out when there is the pressure and other factors such as wind.. the mixing is a byproduct of pattern, long before there was imac and the toc was flown with pattern planes mixing was used mechanically, it came out of a need to be the best and to get as much help to-wards that goal as legal. Why cant they use gyros, sure full size jets use them but do they take away the skill factor... this is a whole topic in itself...

Back to the question, rudder to aileron mix should be always on, it affects the plane in every attitude but again personal preference, maybe it may hurt the 3d performance ?? Probably the best way is to put it on a switch and then fly around with it on, if it does something funny turn it off, if not take it off the switch..

Knife Edge Switch
 

I was flying today and this thread came to mind. I never really thought much about it until a few days ago reading on here.
Try a rolling circle with your knife edge switch turned on. I guess it would depend on who bad your plane rolls and pitches during knife edge.
Take the U-CAN-DO-3D for example. Knife edge on that plane, plain sucks.

Dave

Knife Edge Switch
 

Interesting thread. I'll put up another vote for mixing, and leaving it on. I do fly IMAC, and prefer sequence type manuevers as opposed to 3D type stuff. I'm sure i get as much enjoyment doing one turn rolling circles as other guys get doing harriers. My Extra does pitch couple with rudder, but doesn't roll couple. My Pitts roll couples and pitch couples more than ANY plane I've owned. I use mixes in both (more, of course in the Pitts) so that when I give a rudder command, I want YAW, not yaw+pitch, or yaw+roll. Since for me, I can think of no situation where yaw+pitch is desireable, the mixes are on all the time, rather than on a switch. I realize that setting up both sides of a knife edge mix yields benefits in EVERY manuever that requires the fuselage to be the lifting surface. A four point roll done at one second per point doesn't require much, since the nose won't drop much and can be raised bumping the elevator while inverted. An eight point roll done at 2 seconds per point looks GREAT if the nose is kept "on a string", and requires a lOT more. A 15 second end-to-end slow roll performed with my Pitts without mixes would not only require varying pitch correction, but also the roll rate would change considerably slowing down during the first quarter of the roll as rudder is fed in, and speeding up in the third quarter of the roll as the opposite rudder is fed in. Not saying it can't be done with precision, but I'd personally as soon have the mixes (they're mine, I paid for them when I bought the transmitter, and I'm GONNA use them!!!) :D I can count very well also, but when I do my taxes, I'd as soon use a calculator.

Pattern planes have most coupling issues designed out, with the emphasis on flying charazcteristics, not appearance. IMAC type planes are additionally concerned with appearance, so flight characteristics sometimes suffer. Radios provide a tool that minimizes adverse characteristics, so as to allow the pilot to fly the MANUEVER rather than flying the PLANE, and for me, that's great.

Your mileage may vary.....
Tim