You need to PLAN and DESIGN this first, worry about details later... You might think about these areas:
Read about this! Wikipedia, Google. This is what Arduino was largely for for Art and Installation work
You need sketches and dimensions. You need mechanical considerations, materials, strengths, forces, power
You need circuit diagrams, components choices, electrical power design, Arduino interfaces, power control
You need written narratives of How This Works, and then Arduino Software Sketches
2 weeks ago my wife and I did a weeklong Arduino101 class and the students went through those design sections, and I believe it helped reduce the flailing around.
Think: STEPWISE REFINEMENT
Come back with some design ideas...
...and if you're an Arduino Newbie, start here: http://ArduinoInfo.Info