I have to credit this trick to Scott Lidgey. When you are rotating an actor in Composer, you can control the amount of revolution and make sure it rotates at a constant velocity. The trick to this is to click on the triad when you go to rotate and do not drag it. You will notice the property task pane ask you how many degrees. Now you can type any number you want and the actor will rotate that over time. I have created a video show this process.