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        Discussion Flying a Scale Cub/ mixing rud-ail?

#1 captscotty Oct 10, 2012 10:04 AM

Flying a Scale Cub/ mixing rud-ail?
 
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Hello
I'm flying a 1/6 Maxford USA Piper L-4 and think I need to mix some rudder to aileron, just not sure how to. The plane wants to adverse yaw if flying on the slow side and is fine at faster than scale speed. I'm using a Futaba 6EXA computer radio so programming mix is an option, I'm just not sure if I use rudder to aileron or vise versa and what percentage? I'm guessing maybe 30%+ to start but anybody have any ideas?

thanks
Scotty

#2 edwin1 Oct 10, 2012 10:16 AM

I would suggest not doing it. A cub needs to be flown with coordinated turns, ie:lead with rudder, control wing bank with ailerons, and elevator to hold it level. In my opinion, if you mix you'll have trouble with side slipping and general cross stick flying. Which is a lot of fun in a cub.
Edwin

PS - Nice looking cub. Should be fun.

#3 captscotty Oct 10, 2012 10:41 AM

Thanks!!
 
I have about 5-6 flights on it since this pic but haven't flown since last February so I was just hoping to make it a little easier to get back on the sticks ie: mainly right stick flying. I do a lot of throttle management just don't use much rudder except knife edge and stall turns....

scotty

#4 edwin1 Oct 10, 2012 10:52 AM

Its a good plane for learning the rudder. Practice doing figure 8's with wings flat. Cross stick flying can be a lot of fun. Side slipping can be used to loose altitude without gaining speed. And nothing looks finer than a cub side slipping down to the runway center line.
Edwin

#5 edwin1 Oct 10, 2012 10:56 AM

Also forgot to mention, using rudder on landings can make a bad landing approach a non-event. Too many pilots use ailerons to line up with the runway which causes problems. When you're low and slow and your wings go to high banks, you loose lift at a time you cant afford to. Use the rudder to line up and ailerons to keep the wings level when slow. It will help landing just about any plane.
Edwin

#6 captscotty Oct 10, 2012 12:22 PM

You're absolutely right!!
 
Thanks Edwin1
You know, I've been a Sport flyer for almost 10 years and really have'nt improved, I just like basic aerobatics, scale 50's type stuff but if I'm going to get any better I gotta learn the rudder. That IS why I got the Cub and you just talked me out of cheatin myself by using mixing......Thank You!!

Scotty

#7 scaleman57 Oct 10, 2012 03:15 PM

I mix rudder 25% it will give you cordinated turns. Most cub flyers will want to use the rudder stick but I cheat, Cubs are great training platforms Ihave been flying them for 30 years and have flomn with and without mix, I preferto use the mix on rudder.

#8 no1isnormal Oct 10, 2012 07:52 PM

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I would also suggest setting up some aileron differential. If not done already. The upward travel should be more than the downward travel. This will help immensely with the adverse yaw condition.

#9 captscotty Oct 10, 2012 09:27 PM

oohh yeeaaaah!
 
I learned from the beginning about differential and always set my ailerons to move more up than down. I was lucky to get training from a long time pattern contestant (prolly 25-30 yrs) that holds clinics every now and again. He suggested I mix rud to ail but I'm just asking for other opinions.....

"preciat the advice"
scotty

#10 Thermalin Oct 10, 2012 09:36 PM

I have a cub... what fun is it if you take the fun out of it. Learn to use the rudder independently / by itself... you'll be a much better pilot. Mixing certainly has its place, though I perfer not to use it for example with elevator and flaps, etc. I prefer to fly the plane myself learning skills as I progress.

#11 ARUP Oct 11, 2012 07:50 AM

+1 Thermalin. Besides, the full scale Cub didn't have 'mixing'!

#12 edwin1 Oct 11, 2012 09:26 AM

Years back another instructor and I would do a demo for the students by having a cross stick contest. To see who could fly the full length of the runway with the most crab and wings the most level with our cubs. Mine was a world models 1/5 and I forget what his was (CG?). He beat me with about a 45deg. Really something to see that. Another fun thing to do is what we called tip toe through the tulips. On a touch and go, land left wheel, then right wheel, then go around. Its harder than it sounds. Cant do any of that without rudder.
Edwin

#13 Lifer Oct 13, 2012 05:22 AM

Mixing rudder and aileron is a great idea on any plane with a flat-bottom airfoil. Differential is also necessary to avoid adverse yaw. Finally, neither of the methods has anything to do with rudder in the turns, as you need to HOLD rudder input throughout the turn, NOT just at the point you initiate the roll prior to the turn. If possible, find the local general aviation airport and find a Cub pilot and talk to him/her.

#14 us185damiani Oct 13, 2012 08:19 AM

Mixing only works for the initial roll in. normal turns to maintain coordination rudder into the turn then opposite aileron to prevent roll coupling from over banking the airplane. Same way you do it in a real one.

#15 pmackenzie Oct 13, 2012 08:26 AM

Two things:
- You actually want an aileron to rudder mix, aileron is the master and rudder is the slave.
- The amount you need is usually quite small, less than 10%.

It is not cheating, nor will it prevent you from cross controlling if you want to.
It simply makes flying the model easier since you are not in it to feel the adverse yaw when it happens. If you give 20% aileron it will amount to 2% rudder. No one is that good on the sticks.:)

Differential will also help, but nothing wrong with a bit of aileron to rudder mix if it works.

Put it on a switch and try it both ways. When you get the percent right you won't notice anything but that the model flies smoothly.

What transmitter are you using? Adding a mix is usually very easy.

Pat MacKenzie


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