This is MOC of an amusement airplane ride, a very common ride in China. While the superstructure is rotating, the arms which carry the airplanes are swinging up and down periodically. At the same time, the propeller of the airplane is rotating (this feature is not in real word due to the danger).
It is my very first MOC. I just enter LEGO Technic from 42009 and have the second set of 10247. Thinking of the huge amount of vehicle MOCs, I decide to put my effort on non-vehicle only. This design challenges me in generating a periodical swing movement in a very limited space. It seems intuitively to use LA to lift the arm. But I cannot make an axle to change the rotation direction periodically from a uni-directional axle at that time. Maybe I can try this type next version.
I use LDD for 99% of the time and takes me 1 year (I have job and kid...). Building up takes me 10 hours.
Here is the video and pictures. Note the minifig is at the high position in the beginning, and at the low position after rotating.
I also build the function chain in LDD to show how it works
The input axle is green, that drives the upper part of turntable that connects to the superstructure. The lower part of turntable is fixed with the base (not shown)
The axle in the middle of turntable that with black 12t is fixed with the base, not rotating. So when the superstructure rotating, the yellow 12t is rolling on the black 12t and transfer the power to the two yellow gear sets. For one of the two yellow gear sets, it has a 8t-24t gear down and transfer the power to the two ending 16t.
Either 16t drives two crank, the blue and red, which is 180 degree out of phase. That results in an alternate movement of up and down. Then with 7L beam as a rod, they push and pull structures with toothbar in the next figure.
The yellow 12t also pass the power to the pink 12t, which (the pink parts) split the power to 4 orthogonal directions for 4 airplanes' propellers after 2 stages of 20t-12t gear up (brown part).
Back to the blue/red crank and rod in the previous figure, they push and pull the blue/red structure, either contains two toothbars.
The toothbar moves up and down of +/-1L(5t). It is gear down by 12t-20t, and result in 5/20*360=90degree of swing of the 4L half beam, that lift the arms.
The toothbar structures are limited by a sliding system to move up/down only.