Jeanie - Alan Cassidy's book 'Better Aerobatics' far and away has the best decription of the rolling turn compared to any other acro book in or out of print. Same goes for most of the other aerobatic figures. Well worth owning.
Good rollers are a challenge. You should be able to do good straight-and-level rolls before starting on the roller because during the roller you still must roll the nose around the same 'sacred circle' as you would during a basic level roll. Ideally, you integrate the roll with the turn at a constant and even rate, and establish how many degrees of turn you will do for a given amount of roll before starting the maneuver. In competition, the rates come in (3) flavors - 1) A full roll per 90 degrees of turn, 2) Full roll per 120 degrees of turn, 3) Full roll per 180 degrees of turn. You begin to see #1 in the Intermediate Category, flying a "90 degree turn with one roll in". "In" meaning inside...that your turn and roll are in the same direction as viewed from the ground. Outside rollers have the turn and roll going in opposite directions. People think outside rollers are harder, but they're not really. They just need a little more rudder at the critical points, and the timing is a little different. The concept is the same.
Anyway, I'd suggest starting with the basic 90 degree turn with one (inside) roll. It stands to reason that you should be 45 degrees off your starting heading as you reach inverted. Pick good ground feature lines. Depending on the airplane, it may help to start the roller from a little less than level cruise speed...and add full power as you start the maneuver. You may want to start with cruise speed in the Super D to retain aileron effectiveness, since the roll really wants to slow down when you get to the cross-controlled part. Roll rate should remain constant.
If you want to roll/turn left, simultaneously apply quite a bit of left rudder and some aileron...how much depends on the airplane. You'll have to learn the inputs in the Super D. The faster you roll, the faster you must turn. But if you roll too fast, it may require so much elevator and rudder that you begin to snap out of the turn. Snapping out can also happen if your airspeed gets too low. It's an energy killing maneuver. It is also an extremely UNcoordinated maneuver...probably more than any other maneuver. It's also the most likely to make newbies sick, due to the severe back and forth yawing and pos/neg G transitions.
The objective is to keep the nose consistently moving through the turn by whatever means necessary, while maintaining situational awareness, and maintaining altitude. The left rudder starts the nose moving into the turn, and as you depart the wings-level attitude, you must start progressively applying aft elevator to get the wing lift vector helping the turn. Too much elevator too early and you'll climb. Too little and you'll drop altitude and won't evenly integrate the roll/turn. As your bank steepens, you must start reducing your left rudder input so you're not forcing the nose down. You will reach a point around 60 degrees of bank where the rudder is momentarily neutral, and aft stick reaches its highest point due to wing lift vector alone sustaining the turn. This only lasts an instant though, and the inputs must constantly change...just like the level roll.
As you approach knife edge, you must start applying right rudder to keep the nose up, and you must start reducing the aft stick. Right rudder continues to increase, and the stick keeps moving forward so that by the time you're inverted wings level, you have the same forward stick you'd be using for a normal level roll, but you're sustaining the turn with right rudder. You need a LOT of right rudder to keep the turn going when you're around 30 degrees shy of wings level inverted.
As you pass through inverted level, you start reducing your right rudder input, and you continue to increase forward stick so that you enter an inverted turn. Again, once you reach about 60 degrees of bank past the inverted wings level attitude, your rudder will momentarily be neutral, and the turn sustained by forward stick. As you approach the second knife edge point, you start coming back in with left rudder and reducing your forward stick. After leaving the second knife edge point, you transition through neutral elevator and start applying aft stick and increase your left rudder input to keep the nose moving through the final few degrees of turn. And similiar to what I mentioned above during the inverted portion, you need a LOT of left rudder when you're about 30 degrees shy of wings level upright. Simultaneously neutralize the ailerons and rudder when you're done. Hopefully this will happen perfectly on heading.
Oh, and before trying rollers, it also helps to get comfortable with steep (min. 60 degree) inverted turns so you get used to the push. You should see between 2 and 2.5Gs on the meter (positive and negative) after the rolling turn. Get used to pushing around -2.5G during the inverted turn.
And practice rollers in both directions. Practice them from inverted to inverted. When you get bored with that, start doing some inside/out rollers...part of the turn being inside roll and part being outside roll...or vice versa...or alternating. Those will show up in Advanced. Lots of different combinations. Plenty to keep us busy practicing.
And again, get Cassidy's book for much better detail than I can write here.
