Roo Man

My Feedback: (1)

Just received a Super Cub with electric motor [my first elec]. It's the Hobbico 48" wing span, receiver ready that was featured in the last AMA magazine.

I got it together today, balanced, set control surface rates p/instructions added a slight level of pre mix for Ail to Rudder and took it out to the street to practice taxing. Boy is it a handfull. It seems to not respond to rudder, then it goes crazy. I have 100% expo on rudder. I was able to makle some improvements by trimming the rudder for a straight roll out and got best results by not touching anything. It did get the tail off the ground a couple of times and control seemed to improve but had to get out of the throttle for fear of lifting off.

Does anyone have any suggestions?

Gary

Lnewqban

http://www.rcuniverse.com/magazine/a...article_id=866

novatubbed

My Feedback: (13)

all cubs are a handfull on take off i have a 78 inch and its all rudder until the tail gear comes off the ground.

jetmech05

Always taxi a tail dragger with up elevator.....helps keep the tail on the ground, helping with steering......

TedMo

Sounds to me that you lack a steerable tail wheel? However if it has one main thing is to hold up elevator to keep tail wheel on ground until just before flying speed is reached.

TFF

I find you dont need the expo on the rudder like the other controls. When I move the rudder I want something to happen. When flying a real plane it can be pretty herky jerky as what most do is rhythmically move the rudder back and forth and when you need to make a correction you hold the control for a couple of seconds before going back to the rhythm. It is too hard to do that with a model as you are not sitting inside; that is the reason you need fast controls for rudder, your not inside. It is always a delayed reaction for control.

MinnFlyer

My Feedback: (4)

Turn your expo down to about 30%

100% is too much!

Steve Percifield

My Feedback: (14)

Makr sure it has some "toe In", just like your car. AND take off on grass, not any type of hard top.

Rodney

Like minniflyer said, reduce that expo to about 30 to 50%. Also, that toe in is very advisable, difficult to taxi without it.

Roo Man

My Feedback: (1)

Thanks all,

I will add some toe in and reduce expo as suggested and try it again.

Gary

Lomcevak Duck

My Feedback: (14)

Try this:

Taxi to the center of the runway (while taxiing, hold up elevator) and line up on the center line. Stop for just a second at idle.
Advance the throttle SLOWLY. You should not be at full throttle until after the tail wheel is off the ground.
Take all of the exponential out of the rudder and make small adjustments as soon as the plane deviates from the center line in the least. You get into trouble when you let the plane turn significantly and you will begin fish tailing and chasing the centerline. Remember to stay ahead of the action and tell the airplane to go where you want it to go, as opposed to reacting to what the airplane has done.

jester_s1

Gear setup is a big deal with any plane, but especially a Cub. Make sure your main wheels are angled the same. Measure it. Don't eyeball it. The simplest way is to put a straightedge on each wheel so you can really see the angle from 2-3 feet away. The toe in needs to be the same relative to the centerline of the fuselage. Once your main gear is straight, adjust your rudder to be straight, then adjust the tailwheel to make it roll straight. Your goal is to set up the landing gear so that the plane rolls the same direction that it flies as you transition from the takeoff. Then ground handling becomes a simple matter of managing the tendency to pull left at the beginning and learning the plane's quirks on taxiing.

acejinx

This may be more than you are looking for but on my super squirly warbirds I use a gyro for the tail. The cheap ones from Hobby King work fine. That way unless you command a change in yaw the gyro is actively trying to counter any unexpected rotation. In the air I don't notice it all that much, except when stalling, then if a wing drops the rudder actively works to correct it.

David Bathe

It's all about engine and power delivery.Use very little... applied very slowly.If you're above 1/3rd throttle as you're about to break ground...you've over gunned it!Once airborn advance the thottle up as normal.Old school design, flys on the wing...not the engine.

BillyGoat

Before you try Toe-in read this.... http://www.rcuniverse.com/forum/m_45...tm.htm#9866383

Post #18 presents a pretty good argument that it should be toe-out.

jester_s1

I've tried it both ways and toe-in has been more stable in my experience. The toe-out does help you recover if you do get out of shape, but toe-in helps to keep you from getting out of shape. So on the more ornery planes (Like WWI biplanes) toe-out my help more than toe-in, but on a Cub or any sport model toe-in is the way to go.