1) Take a piece of paper.
2) Write down budget.
3) Buy: Power supply, Actuators, Control board, cables and scrap metal and wood.
4) Figure out how it fits together.
5) Put them together.
6) Test
7) If it fails, write down problems you observe.
8) Wait until you find solution.
9) Note the solution on that piece of paper.
10) Implement solution.
11) Repeat  from 6.