I have a tiger 2 with a os 46fx the airplane flies good but needs some help with the rolling, were do i start with aileron differential.

A 1/16 of a inch between the ailerons will get you where you need to go. Try this: 1/4" on the up aileron, 5/16" on the down aileron. Set these #'s as your max throw (or high rate if you have dual rates) or tame it down to your flying style (or less throw on low rate) Do not go anymore then a 1/16" of a inch on Aileron differential. It will mess up how the plane handles in other areas.

thanks for the tip. can I use the off set on the control arms to do this, then fine tune it with the radio settings?

Does your set up use adjustable aileron torque rods? If you can post a picture of what your set up is on the ailerons.... It would be easier to tell you how to go about doing it.

The Tiger 2 has a semi-symmetrical wing so you might need more differential.

I have a servo in each wing and I have put 4-40 threaded standoffs on each aileron the conrtol rod is connected with a plastic connector to the standoff and the rod has a z bend connecting to the servo wheel. I was thinking the holes in the servo wheel it self.

If your radio can be programmed for differential I would setup the linkage so there is no differential and do it all in the radio programming. That would give you the flexibility to easily change it. Before programmable radios we did it with the linkage configuration.

Just a combination question/thought on the differential aileron question. Impactiq mentioned above to have the throw of the down aileron have a bit more than the throw of the up aileron. In full sized airplanes, I have always heard the down aileron should be less than the up aileron. The reason given is that the down aileron is increasing lift on that wing with the corresponding increase in drag which then causes yaw opposite the turn direction. A solution to the induced yaw of the down aileron was to have the up aileron deflect a bit more than the down aileron. Would this not also apply to our sized planes?

I am no expert here.... but I would half to lean towards the airfoil of the wing would play a big part in what happens with aileron differential.....same goes for amount of Dihedral in a wing too.