This crazy little device is loads of fun! It makes for a great desk piece that'll keep visitors entertained for as long as its batteries will last.
This internet phenomena has been referred to as the most useless machine ever or the leave me alone box, and if you've ever seen it in action it's pretty obvious why. Finding good instructions on how to make this thing is hard, so hopefully my instructions help some of you out!

Before getting started I gotta give credit where it is deserved. I learned how to go about the servo modification and the wiring method from thejetdrvr on YouTube.

Now lets get started!

Step 1: Supplies

Things You'll Need

Double pull double throw toggle switch
Rocker switch
One triple A battery holder (and the batteries)
Servo
Wire
Hinges
Wood for a box (or a pre-made box)
Wood for a finger
Soldering iron
Saw
Wood glue*
Screws*
Patience
Paper
Measuring tools

Items with * may or may not be needed.

Step 2: Design

It is important to have a good solid design for your box before you begin making anything. I made the mistake of thinking otherwise. Please learn from my mistake! It is important to keep the shape of the finger, the size of the box, and the positioning of all your components in mind.

There are two methods I really like to use to figure out my design before I begin building. I use Google Sketchup to make the components for my box and then I play with positioning and box size until I find something I like. But another method involves cutting out pieces of paper that are the same sizes of your components and moving them around on a drawn box. If you use this second method an easy way to figure out the shape of the finger is to draw it pushing the toggle switch and then pivoting it down from where you want the servo to see if it fits in the box. You'll then adjust the shape and size accordingly until you have an arm that will work.

As far as how the box works, you have a toggle switch that, when pushed, causes the servo to move out of the box and push the toggle switch the opposite way, when the switch is in this position it reverses the movement of the servo, causing the arm to go back in the box. Once the arm is back in the box it pushes against the rocker switch, which causes the servo to stop moving.

The wiring for the box can be seen in the pictures. The wiring is so jumbled up that I thought a diagram showing how the components should be wired would be easier to understand.

Step 3: Servo Modification

I used a normal servo and just modified it to be a continuous rotation servo. I think that this method is cheapest and easiest.

Begin by opening the servo by taking out the four screws on the bottom and the setscrew on the top of the servo. You're then going to remove the middle gear that prevents you from taking out the black gear that sticks out of the housing. You want to take out the black gear, locate the little tab that makes it so that the servo can't spin 360 degrees, cut it off, and then sand it smooth. This is the first step in modifying the servo.

Next you want to snip the wires leading into the servo, get rid of the white one and then re-solder the black and red wires to the power terminals on the board of the servo. You'll want to cut a small hole in the plastic housing so that the wires can come out of it, it'll be obvious where it needs to be. All of this is can be seen in the pictures. Replace the housing and the screws that hold the servo together and you're done modifying the servo.

Step 4: The Box

The box is a little difficult. That may be because I had never tried to build a box before this however. BE SURE TO KEEP THE BOX'S CORNERS AS SQUARE AS POSSIBLE! It is nice to use a square dowel as supports to hold the servo and/or rocker switch in place. I don't believe I should spell out how to build the box, because it is very straight forward; cut out the pieces and screw/glue them together. However, I will warn you about some of the things to keep in mind that I didn't the first time I made this gizmo. When cutting the two pieces for the lid, don't cut one large piece and then cut it in half. The saw blade will cause a gap that makes the lid look nasty.

Some people make both sides of the box pivot on hinges so they can open the top completely and service the insides, but depending on how large the side of the lid that has to pivot is, you may or may not need to do this.

While making the box, attach three sides and the bottom together first. Leaving one of the sides and the top off make it far easier to place everything on the inside where it needs to go.

Step 5: Put It All Together

I suggest doing the wiring and the box separately and then putting the two together, this way you can make sure the servo and switches act like they should so they don't break when they're in the box.

Make sure to move the finger by hand when it is connected to the servo to make sure it comes out of the box like it should and fits in the box. If it doesn't then fix it before you power the servo and end up breaking it.

Once your confident with your leave me alone box pop some batteries in and watch it go!