The power rangers were at MGM Studios and when we were there (July 5-10, last month) the times were 10:45, 11:45, 12:45 etc, I think almost each hour, but for ONLY 15 minutes. It's a pretty big deal. The music starts and they all come out in poses on their power rangers car. There are 5 of them and an announcer introduces each of them and they each do their trademark stunt or pose. Then they all go to their assigned spots for autographs and pictures.
The only thing to be warned about is that it's JUST 15 minutes and no matter if you are the next one in line, when they say they are leaving, they leave. We were the next one in line and were left high and dry b/c the cast member said no more autographs. We came back the next hour early and asked where the assigned spots would be and stood there for 10 minutes. I believe it was the green, white, pink, red, and blue/silver one. It was worth the wait to see my happy boys!
I cant think of the exact location, but they were down the street from Al's Toy Barn...HTH