Hi, I have a quesstion about trim, plane is wanting to bank slightly left how does one determine if it's the rudder or ailereons?
I trimmed the rudder slightly left for ground handlig then airborn trim ailereons to componsate the defunkt rudder is what I think is happeming.

Fix the steering without messing with the rudder trim. IE, reset the nose wheel or tail wheel.

Have you balanced the plane across the wings?

Many people only balance a plane Forward and Aft because that is where the C of G is, forgetting that the wings have to be balanced too.

As barracudahockey said - reset the nose wheel and leave the rudder alone.

But also check out the other things like lateral balance.

First, balance the model longitudinally (not just center of gravity). Add weight as needed to the light wing.

In flight - trim it to level flight at 3/4 throttle with the aileron, remember the clicks needed,and then try a vertical loop (into the wind). If it doesn't stay in the same vertical plane go back to the original aileron setting and adjust with rudder. Repeat the loop test.

^^^^ This

Ok thanks, hypothetically all is straight neutral wings balanced ect, slight trim adjustment being made with either ailron or rudder rusults in level forward flight, then guessing on the ground you just look at the surface alignments for assesment.
Like if you see the rudder is now out of alighnment with verticle fin and the plane flies level it would indicate the ailrons may be what actually need trimmed and start all over again.
Sorry for being a simple mind, it's just that yeasterday I maiden flew my scratch bult and while up and away I was nervous as heck She was banking a litte not bad but certainly not hands off, I did manage to trim it level with ailrons but during the first few minutes of flight my mind was saying trim rudder only because I learned on a rudder, but now I have these ailrons but I certainly know the rudder has a great impact too, I just need a little more flight time I guess.

Generally speaking, If it rolls, it's ailerons. If it veers without the roll, it's rudder. Remembering that this is a beginners forum, a lot of advanced instruction may be unnecessary at this point.

Some adjustment - trim is usually necessary, a couple of clicks one way or another is usually, probably necessary on the first flight of the day. Once done at flying throttle setting - meaning take off, level out at some throttle level, not full open, although some people think the throttle is a switch.. full open or fully closed , set the throttle for flying, perhaps a couple of clicks over half, then trim the plane for straight and level flight and fly on.

Some times, this is done on the maiden and can be adjusted out mechanically after the flight. Sometimes, this takes several flights to get it right, but once done, you can take off, set the flight throttle setting for what I said was flying speed, then make the minor trim adjustments for straight and level, and then enjoy it and fly the plane.

CGr.

Or possible twist issues in the wing if you're rolling.

take it verticle into the wind. if it falls off to the side the the rudder is kicked or the fuselage is angled

I'd guess the odds are about 100 to 1 that there is a slight warp in the wings; i.e. one has a very slight higher angle of attack than the other.

Hi!
Agree!
The first thing you should check when trimmining an airplane is always the wing! Does it have wash-out or wash-in or is it built straight?
The second thing is always to set the aileron,elevator and rudder straight and use as small trows as possible but using as much trow on the transmitter as possble (100-150% if you are a JR or Spektrum flier)! Never reduce trow elektronicly,at least not much.
Then you fly the plane!
Be careful how the plane reacts!

The goal when trimming all planes is to use as less elevator and aileron trow as possible and still be able to stall (and controll) the plane when you want to at very low speed.
The plane should not dip it's nose at low speed ,it should stall over it's wing tip!! But it should do so when you want it ,and do the same whenever you give up-elevator att low speed. That's very important to remember!
You check for correct Cof G by flying the plane straight ahead at full speed and then do a 90 degree plylon turn (just using aileron and elevator) . The plane should just float through the turn without dropping it's nose! If you notice a slight tendency to drop the nose the plane is nose heavy!

Did anyone actually read that he adjusted the rudder trim to fix ground handling?

LOL!  No.

So, keep it on the ground and you'll be OK if you trimmed for ground action. 

Use right rudder when taking off and trim for flight operations if you want it trimmed for flight.

yes... andit was pointed out to adjust the wheel not the rudder.