I own a Pilot 330sc 35% and I am in the process of trimming the airframe for IMAC and freestyle.

I have never setup aileron differential in any of my planes but in this particular occasion, I want to setup the airframe properly and so I came across this new thing for me.

Although I understand what aileron differential is, I don’t know how to identify this and whether or not I need it.

Been following many threads and the only thing I came across to Identify this behaviour, is flying Upwind 45 degrees up line and turn the plane left or right to see if the plane “walks” to either side when rolling...

Did this and notice no “walking” torwards left or right.

My rolls seem axial to me but it is hard work to complete a smooth 360 roll pass keeping it in line..

Any other tips and experiences to share?

Thanks!

Differential does help the axial roll. The more axial the roll, the higher you will score points. Some airplanes dont need differential, because it already rolls axially. You will have to experiment with values on differential. Someone can tell you 3%, and the roll barrels worse than it did before...

Keep in mind that when inverted differential works against you. It’s really intended for high aspect ratio wings that are usually upright, such as gliders. Differential is used to prevent the inside wing from stalling. Not something to obsess over with aerobats.

Differential ailerons is used to mitigate adverse yaw.
Since the downward deflected aileron produces more lift as
evidenced by the wing raising, it also produces more drag.
This added drag causes the wing to slow down slightly.
This results in the aircraft yawing toward the wing which
had experienced an increase in lift (and drag). From the
pilot’s perspective, the yaw is opposite the direction of the
bank. The adverse yaw is a result of differential drag and the
slight difference in the velocity of the left and right wings.

More pronounced in Cub type high wings. The downward deflected barndoor aileron creates almost enough adverse yaw to prevent a turn. That's why it takes the rudder to overcome it and make coordinated turns.

I have not needed to do any differential adjustments but i also use an angle meter to set up ailerons. They match at full deflection in all my rates. When I set up my throws, I get it as close as possible mechanically and use the radio if needed to find tune with the balance feature.

Peter Goldsmith's trim guide may be helpful.

This may also help.

I agree with the RCA and wmat on those trim charts. We get asked from time to time how we trim out our imac planes. rather than try and explain in great detail the steps necessary, I'll give the person asking my copy of the PG trim guide (always have a copy) and try to give them a small heads up about doing it.

I've used the TRIM App on my iPhone as well.

If your rolls are axial in verticals, it could possibly be that you are tail heavy. Flying a sequence is easier with a slightly more nose heavy set-up than tail heavy set-up.

Follow the checklists and keep repeating them after every trim change, you will get to a well-trimmed plane after a few cycles - be methodical and patient!