Hydro Junkie

But his question was answered. How many people said don't do it and 0% on page 1? How many said to set the ARC to a given number on page 1 or 2, but not using sarcasm in their post? I only saw 1 person say to use coupling and why with an experienced reason for doing so. Almost everyone else said don't do it, to which I agree since the one asking said he is a SELF TITLED BEGINNER.

As to the question as to "Why does a radio have coupling?", there is a very simple reason, Bells and Whistles
Let's look at cars, for example. What do people look for when shopping for a new car:
1) Power and performance(mostly guys in this case)
2) Safety features and comfort(mostly ladies)
3) GPS navigation system
4) Multi-zone air conditioning
5) Multi-channel radios with DVD/CD/IPOD capability
6) Heated/cooled power seats
7) Rear window and remote outside power mirror defrosters

Now, how many do you need? Only #2
How many are add-on niceties? #3 through #7
How many add to the cost of the vehicle, 1,3-7.

Now, let's look at a top of the line radio system and what is needed to fly a full-house aircraft
Needed channels: 4
Available channels: 18
Needed mixes and aids: NONE
Available mixes and aids: 22
Needed telemetry: NONE
Available telemetry: 31 sensors through an S-Bus 2 system
Needed warning systems: None
Audio and shaker warning systems: Low battery warning, timers, telemetry for starters
I'll stop here since I could fill up several posts. The question at this point is why is this all offered? High level competition pilots say they want it and the manufacturer can charge a lot more for it.
What would a radio needed to fly cost? $150 for a four channel with everything
What would the top of the line radio cost? $3000 plus receiver battery, S-Bus2 hubs, telemetry sensors and servos.
Now the question is "WHAT DO YOU REALLY NEED TO FLY?"

jetmech05

This post started and died in 2011. I hope he learned the rudder by now

j.duncker

My Feedback: (2)

YUP ZOMBIE THREAD ALERT

But if anyone interested in the topic stumbles across this thread there is a good answer on the previous page.

I fly lots of different models and find using coupled rudder and ailerons useful on high aspect ratio gliders and biplanes with dihedral.

If you want to try it would recommend using a switch to activate the mix and start off with 10% unless you have a large rudder with lots of movement in which case 5% would be prudent.

It is good to play around with this sort of thing as you learn about aircraft behavior and the bells and whistles on your tranny.

One final use for coupling rudder to ailerons is to allow a beginner to steer the model on take off with the aileron stick. It is not ideal but some learners find it difficult to use the rudder with the subordinate thumb. I taught a pilot with real problems in this area and finally we added an extra servo to steer the tailwheel and mixed it to the ailerons.

AdamsBro

My Feedback: (14)

JimmyZep,
I'd advise against mixing aileron and rudder at this point. Learning to add bits of rudder into turns and on landing and take-off now independently from aileron inputs is key at this point. Mixing these 2 you will learn how to fly with them always mixed, and there are scenarios where you do want them mixed and when you do not want them mixed. Keep is simple, no mixing, just fly, practice and most importantly have fun!

rcfs

Everything you need to know, the amount of mix whether flat bottom wing (1-to-1) or symmetrical wing (slight) can be found at this page: http://www.rcflightschool.com/Aileron-RudderMixing.pdf

Charlie P.

Whoa! Old thread. First response was the correct one. ("Zero")

For your Rascal (69? I've seen 72" & 110") rudder mix keeps the nose level but would not tighten a turn. Bank it steeper with the ailerons and use the elevator to tighten the turn (and a little opposite rudder to keep the nose up).

I do not use mixing, esp alieron-rudder, because it messes up nice axial rolls.

rcfs

Whoa! Watch that advice! Bank angle determines rate of turn and elevator is used to the keep turn level. Trying to tighten turn with more elevator will affect a climbing turn, speed changes, and various resulting issues. If I told people in full-scale that some are promoting in RC using top rudder in turns to keep the nose up they would be shocked and probably start citing examples of those who have killed themselves trying that.

Charlie P.

We're not flying real aircraft. We're flying models with lighter wing loading in the same atmosphere, so we get away with murder compared to "real" aircraft. He wanted to tighten a turn.

I suppose we could walk him through a Chandelle?

https://en.wikipedia.org/wiki/Chandelle

Oh! That's what I kind of did!

rcfs

Everything you need to know and the answer to your original good question is featured in this article. http://www.rcflightschool.com/Aileron-RudderMixing.pdf FYI. Not only does your radio have A/R mixing, so does the jet liner you last flew, aka, "yaw damper". As you have encountered, there is strong resistance to anyone learning other than the way it has always been done, but some of us know that removing obstacles to pilots success facilitates more rapid learning and thus the opportunity to take on new challenges. The replies above are no different than telling kinder gardeners that they should skip 2+2 and get to work on advanced calculus to ensure that they'll be able to master math in the future. Obviously, that's not how it works.

Hydro Junkie

rcfs, did you learn to drive in an Ferrari or a Corvette or something more mundane like a Torino? Just because you might have all the bells and whistles doesn't mean you have to use them.
Using mixes right from the start doesn't make learning faster, it makes the student overconfident and unable to handle situations that require using the rudder in a non-vanilla manner, or at all in some cases.
Just a little FYI, a "yaw damper" is part of the auto pilot system. It operates only as needed and is controlled by computer inputs when the pilot inputs a new heading or the plane varies off it's programmed flight path. It in no way works the same as AR coupling where the rudder is given as much movement as the ailerons

rcfs

The need to use coordinated rudder to counter adverse yaw is principally an issue with flat bottom airfoil airplanes. Adverse Yaw is negligible with symmetrical wing aircraft. Hence, utilizing A/R on a flat bottom wing primary trainer results in axial roll and bank behavior that mirrors a symmetrical wing airplane and therefore pilots flying with A/R mixing are learning from day one the very same techniques used to fly higher performance airplanes. E.g., several hundred of my primary students that learned to fly with mixing are able when they return for aerobatic training to perform basic rolls, loops, Immelmans, and Cubans all within the first flight flying a symmetrical wing Big Stick since they don't require a transition period.

Charlie P.

If I had to fly my models like commercial airline pilots must their aircraft I would have taken up something more exciting like golf many years ago. Zzzzzzzz.

Does an Airbus A320 have a nice axial roll or good knife-edge properties?

Hydro Junkie

The only passenger jet that I know of to ever be rolled 360 in flight was the first Boeing 707 and it wasn't anywhere close to a text book axial roll. Knife edge? That would be interesting to see, considering all the fuel would end up outboard in one wing and inboard on the other, resulting in a totally unbalanced condition

jetmech05

Hydro there baffles inside of tanks to prevent the fuel migrating inside of the tanks.

rcfs

The objective when maneuvering a jet is making sure that the old lady in row 29 doesn't spill her glass of wine. My objective when instructing is t get pilots enjoying the “flying on rails” performance of symmetrical wing sport models. Symmetrical wing airplanes do not require A/R mixing because adverse yaw is minimal with this type. Ultimately, the aim of A/R mixing is to help new pilots to fly sport planes that don’t require A/R mixing and comfortably using the rudder on the left stick for aerobatics, but in hours as compared to months or years! Once again, it's all in the article: http://www.rcflightschool.com/Aileron-RudderMixing.pdf

j.duncker

My Feedback: (2)

I remember a report from a BA captain saying that the Concorde had been rolled.twice.

Hydro Junkie

Trust me, been in enough jetliner wet tanks to know how they are set up. That being said, the fuel can still move to one end of the tank when tipping the plane on a wingtip. A 727, for example, had an inboard wing tank that fills the entire wing, spar to spar and top to bottom, with easy access from wing root to about half way out toward the tip. That's a lot of weight if the tank isn't fully filled. Fortunately, the fuel pumps are set up so that the outboard tanks are emptied first, then the inboard tanks rather than burning fuel out of all five tanks at once. This takes a majority of the stress off the structure in the event of an emergency landing,

rcfs

I wish you guys would go back to sharing your philosophies regarding why novice pilots should not take advantage of aileron rudder mixing aimed at making the airplane handle more honestly and precisely. I'm planning on referencing some of your responses (anonymously) in a series of articles I'm writing this winter for Model Aviation on the primary reasons why typically only 20% of club members fly and of them few fly in wind above 10 mph.

buzzard bait

Good for you rcfs, should be a fun article to read! Should beginners learn on planes that are intentionally poor designs so they learn about rudder coordination? Of course not. Then what's wrong with coupled rudder? Absolutely nothing. I don't think it matters one way or the other.

I flew RC for 30 some years before I started using coupled rudder on aileron a few years ago. No airplane has pure roll or yaw responses, they all have some degree of coupling inherent in the design and the effect varies with speed and incidence. When you add rudder coupling you make those "side effects" a little more favorable, that's all. I like it on high wing types that have some dihedral, and on some of my biplanes.

A beginner who uses rudder coupling will not be deprived of some important lesson. He or she will just have a little bit better flying airplane. That is all. If you want to teach rudder, then go ahead and start using it. Any of my planes with coupling can be cross controlled just fine. If you use 20% rudder coupling, for example, then it is nothing to over-ride it with the rudder stick in order to do a slip. If you want turns better coordinated, you'll need some rudder now and then whether you have coupling or not because the effect depends on speed and incidence. It is no different from using aileron differential, which is also no magic bullet. However, coupling usually does work better than differential.

On the other hand, you can learn perfectly well without it, which is what I did years ago. In fact, I learned with just rudder and throttle. Adding an elevator servo was a thrill! Later I flew 4 channel planes. Now I fly with computer radios and use a mix or two sometimes. No big deal.

Jim

rcfs

I'm with you Buzzard Bait. The need to use coordinated rudder to counter adverse yaw is principally an issue with flat bottom airfoil airplanes and moderately needed with semi-symmetrical airfoils. Adverse Yaw is negligible with symmetrical wing aircraft. Hence, utilizing A/R on a flat bottom wing primary trainer results in axial roll and bank behavior that mirrors a symmetrical wing airplane and therefore pilots flying with A/R mixing are learning from day one the very same techniques used to fly higher performance airplanes. Once again, when it's applicable and what degree is all in the article: http://www.rcflightschool.com/Aileron-RudderMixing.pdf

AdamsBro

My Feedback: (14)

this post is way out of control. just my 2 cents.
use aileron to rudder mix once you know how to fly, if its something you wanna play around with.
other than that, for a beginner, learn to use both sticks.

rcfs

Excerpted from One Week To Solo manual…

In this section: Pg-18 illustrates the cause and effect of adverse yaw. As the name implies, adverse yaw is an adverse condition that delays achieving solo abilities.

Struggling and committing to many hours of practice before soloing has been the assumed normal burden of the student until his skills improve. Unknowingly and unnecessarily, novices flying with adverse yaw have been fighting an additional challenge: Most novice pilots assume that a lack of correlation between their control inputs (and intentions) and the plane’s response to be strictly the need for more practice, when in fact, adverse yaw is largely the reason!

Pg-19 illustrates coordinating rudder with the ailerons to eliminate adverse yaw.

Pg-20 & 21 illustrate the efficient setup of aileron/rudder (A/R) mixing or coupling that 1st U.S. R/C Flight School uses to automatically coordinate the rudder with the aileron while banking and correcting turns, adjusting course, rolling, etc..

Note: The School’s primary purpose mandates taking advantage of all the tools available, including the use of A/R mixing, to ensure every student’s ability to safely solo in all kinds of conditions in less than a week C with the experience and knowledge that they will then use that foundation and confidence to continue learning and advancing on their own.

Pg-22 & 23 illustrate how learning to fly with A/R mixing or coupling instills good habits, promotes sport flying, and accelerates future progress.

Pg-24 & 25 address some common questions about A/R mixing, while also explaining some of the misconceptions held by those who have never actually tried it.

Key point to remember: A/R mixing or coupling accelerate achievement of safe and independent solo abilities. After that, everything else is just practice!