Ernie Misner

I am wondering how many of you routinely mix out bad rudder pitching habits? For example every plane I have ever had pitches one way or the other during knife edge. My feeling is that why not just mix that out with the transmitter right from the start, whereas another person said he'd be learning more just to use the sticks.

What other mixes would you routinely use when setting up your plane?

Thanks,

Ernie

wgeffon

My Feedback: (4)

Ernie,

Mix it out and leave the mix on all the time.
I find it helps.

kevod

My Feedback: (7)

Hi Ernie,

I always have rudder to elevator & rudder to aileron mixing turned on on my GP Extra 330L 1/3 scale.
From my understanding the adverse rudder pitching and rolling tendencies of most airplanes affect the airplane in any attitude, whether it be in a knife edge or up/downline, so on. So if your plane pitches to the belly in knife edge, it will more than likely do the same thing in an upline.

I don't see any reason that you should not mix these into the radio as this is easily done. I am all for learning to clean up the flying with the sticks, but it is just that much less you will have to worry about while flying if the radio automatically takes care of it for you.

Some people also mix a small amount of down elevator with low/idle throttle which helps with downlines.

I am speaking more from an IMAC perspective than 3D, as that is the type of flying that I do.

-- Kevod

rightflyer

Of course, every plane is different and it takes some experimentation, but what is a good start point (%) for these mixes? (rudder-aileron; rudder-elevator )

3D ONdaEDGE

Depending on the plane, and most of them are like this, 10% down elevator to full rudder. On most planes there is a little more down applied to one rudder direction that the other. But I have always found 10% to be a good starting point. Most of my smaller planes need a little more and most of my bigger ones need a little less.

wgeffon

My Feedback: (4)

Hmm,

I've never flown a plane that needed down with rudder. Its generally up that is needed.

majortom-RCU

My Feedback: (40)

My experience is similar to 3D ONdaEdge, start with 10% down rudder to elevator, then adjust from there. Also rudder to aileron, start with 5% and adjust for flat turns with medium rudder. These are pretty much standard mixes for every plane I've done over the past few years.

If I'm building, I angle the firewall for 2-1/2Ëš right thrust. If it's an ARF with firewall not angled, I mix throttle to rudder, usually from about 2/3 throttle on up. I have done throttle to elevator on occasion, whether for vertical thrust offset or straight downlines.

wgeffon

My Feedback: (4)

What planes have you guys needed Down with?
Rudder to Aileron:
Opposite direction or same as rudder?

Ernie Misner

The only plane I had that required down elevator was a plane that had the rudder hinge line angled slightly back as opposed to straight up and down. Ever notice that some planes have that hinge line angled back? Whether they do this for streamlined looks or for any purpose I am not sure. If the backward angle is too much it will pitch the nose upward much like a v-tail plane will use "up elevator".

I think that with most planes, the yawing action from the rudder causes the nose to drop and some up elevator is needed.
Ernie

majortom-RCU

My Feedback: (40)

Well, that raises an interesting question. The only plane I've mixed this year is the Accel Katana profile, which I'm still in the early stages with, and I have rudder to down elevator, 9 & 10%, or 10 & 11%, something like that, at the moment. What is interesting is that when I fly an unmixed model, I just about always have to touch in up elevator for level turn with the rudder. But when I mix for neutral pitch on knife-edge, the unmixed model pitches to the canopy, so I mix in down elevator. What I'm after here is a four-point roll that stays on track with elevator only on the upright and inverted points, and rudder only on the knife-edge points. When the wind is blowing, 95% of the time, tracking is always a hassle.

Then once my model is mixed as well as I can get it, from that point on I tend to forget about the mixes (they're always on null switch position) and fly the sticks on everything--because you always have wind and turbulence and whatnot complicating the situation, so I just fly what I'm seeing whereas in the mixing process I tend to look/think/mix/repeat... but after mixing is done, I stop thinking and just fly.

Rudder to aileron is typically to fix an adverse roll, so you mix same aileron to rudder; but if it's a proverse problem, obviously you mix opposite aileron. Mostly a matter of low wing or mid-wing and not enough dihedral.

When I speak of starting a mix at some level-- I don't do any mixing at all for maiden and early flights. I just fly and trim and try my usual tricks without thinking about mixing. But pretty soon the problems start to make themselves clear, and that's when I start making notes and begin the trial and error of mixing. I've heard war stories about Jason and other guys mixing in the air, punching buttons with the TX held up for simultaneous view of plane and TX display, getting everything dialed in in one flight. I'll never be in that class. I mix by flying, landing, mixing with the model idling in front of me, taking off for another trial, another error, etc.

I'm on a new transmitter this season, and all my old mixes got sold with the old one--otherwise I'd have a look and see how I had them set up. As I re-commission my old models here in the new season, I'll mix them all over again.

I do remember now a CAP that did have rudder to up elevator. But most others, my impression is the mix was rudder to down elevator. In any event, there's no room for arbitrary thinking here, you have to fly the model to see what it needs for mixing.

gjeffers

i dont know if this will be of interest to anyone but i did discover that on my ucd60 size when i moved my tank to cg that the weight transfer did alter my knife so that when rudder was applied it dove to the belly a lot harder(100% HARDER) and i figured out that when i moved the tank that it affected the elevator trim to the down about 3-4 clicks making inverted flight almost effortless with no down input, but when i went to knife the extra down was the culprit that influenced the hard dive to the belly, basics, might help someone

3D ONdaEDGE

Im sorry, I meant up. I was thinking the planes pitch down so my brain and fingers got intertwined and I screwed up. Sorry for the confusion.