Two concepts used in building the acrobat machine are horizontal to vertical stability and right angle gearing.

Beveled gears mesh at right angles and keep 1 to 1 gear ratio.
Crown gear and 8 tooth gear mesh at right angles but gear the motion down.

Now make some kind of bending person to do acrobatic moves around the bar.

Motorize and hook up a bunch.

This project can also be done with the new blue sets.
Or the new white sets or WeDo

Build a motorized Swing

Links of Linda Hamilton