Useless Box

Interested in making a useless box? Building this project was a really fun experience for me. Having very little prior knowledge about circuits, making this simple gadget was a great introduction to circuits for me. And, it's really fun to play with once completed!

This project is meant for beginners with little or no experience making circuits, and using an Arduino. I built this project for my Principles of Engineering class taught by Ms. Berbawy. This project was inspired by the Arduino Most Useless Machine Ever Project by rsucgang.

Materials:

Servo motor

Arduino Uno

10k Ohm resistor

9v battery

Small toggle switch

Wires

4 hinges and 16 screws (such as those for a jewelry box)

1/4" wooden boards for laser cutting*

*If you do not have access to a laser cutter, buying a wooden jewelry box from a store to use as the case works fine

Tools:

Soldering iron and solder

Laser Cutter

Drill and different bits

Wire Strippers

Breadboard

Voltmeter

Arduino connection cable

Ruler

Hot glue gun and glue sticks

Wood glue

Adobe Illustrator/SVG editing software

Arduino IDE

*if using a premade jewelry box, you will need a saw

The first thing I did to start once I had assembled all the pieces was to gather all the electronic components and test out the circuit. I created a circuit diagram using Tinkercad to show how I did my wiring.

I installed the Arduino IDE next. I didn't know how to write code for an Arduino yet, so I used test code from The Most Useless Machine. Later on, once I had finished assembling the box completely, I wrote my own code (shown in a later step).

Next, I started working on the case for the Useless Box:

For my first prototype, I bought a premade jewelry box, removed the lid and sawed it in half. Then I reattached each half of the lid. It was not very pretty and I was not happy with how it looked, so I made my own box for the next prototype.

Since Ms. Berbawy has a laser cutter, I decided to laser cut the box out of 1/4" birch.

To do this I used Adobe Illustrator and the 40W ULS 3.5 laser cutter by Universal (which isn't available anymore, but similar laser cutters can be found on their website).

To make the box, I designed two open boxes, one for the bottom and the other for the lid

To make my SVG file I used the the box generator website Makercase

On this website, I selected basic box

Here are the dimensions that I used for the bottom:

Width: 4"

Height: 2.5"

Depth: 7"

Open faced and 1/4" thickness

Finger thickness: around 0.47

Here are my dimensions for the lid:

Width: 4"

Height: 1"

Depth: 7"

Open faced and 1/4" thickness

Finger thickness: around 0.47

Next, I prepared the design files for laser cutting:

I downloaded both files as SVG's and opened them in Adobe Illustrator

I changed the line thickness to 0.1 and changed the color to 255 red

The first time I cut the box out, I decided to saw the lid in half manually. This didn't work because the wood was much more difficult to work with, and the cut turned out very ugly. I decided to remake the lid, and this time I use the laser cutter to create the angled cut. This line cut the sides of the lid into two pieces, and the 45 degree angle made sure they do not get stuck on each other while opening.

The settings I used for my final design are pictured for reference. The 45 degree angle and using the laser cutter definitely did the trick!

Once it had been cut out, I glued and clamped all the pieces together for drying.

Now I had an open lid box for the bottom half, and two pieces that make up the top half. I attached each piece of the top lid onto the bottom half with the hinges and screws. I used a pencil to mark out where I planned to drill each hole on each piece, to make sure that the pieces lined up properly. Once I drilled those holes and screwed in the hinges the case was almost finished.

Modifications I made to the box:

1. Create the hole for the switch: I needed to drill a hole for the switch to stick through near the middle of the lid. I made sure to position the hole close enough to the edge for the arm to reach it. Once I drilled this hole, I stuck the switch through and secured it in place.

2. Make housing for the servo: The first housing I made was made out of wood that I sawed and glued together, but the second one was laser cut. I made this by measuring the servo dimensions and designing a rectangle to fit around the servo. I cut two of these rectangle and glued them together to make the housing thicker.

3. Find the approximate position for the housing: This next step is a bit tricky, I had to find out a spot for the servo housing where once the servo was inside with the arm attached, the arm would line up with the switch. To do this, I took some paper and cut it into an approximate arm shape. I taped this to the servo motor and then stuck the motor in the housing. I used this mock set up to get an idea of where everything would be and found a spot where the arm lined up with the switch. Once I found this spot I glued the housing down into the bottom of the lid.

5. Make the final arm: I made two different designs for the arm, one of them was laser cut and the other was made out of popsicle sticks. For both, I made a mock arm out of paper and then recreated it with the same dimensions but out of the other material.

Once all the modifications to the box had been made, I soldered the circuit.

I created a 3-way solder between the servo, switch, and 5v pin. I made another 3-way solder between the other point on the switch, pin 2, and a wire that will lead to the resistor. Then I soldered the resistor onto the wire and stick the resistor in a ground pin. I did not have to solder the connections from the other ground pin to servo, and pin 9 to the servo.

I was finally ready to complete the box assembly!

I placed the circuit into the box, secured the servo in the housing, and tightened the switch into place. I moved the Arduino to the side, where it was not in the way of the arm.

I glued the arm to the motor using hot glue.

Next, I made my own code for the box. I watched a few Youtube videos about how to move the servo motor, and how to use a switch. I was able to make a simple program that made the arm move the switch back when it was flipped.

During this process I also discovered my arm was not strong enough to push the switch back. I fixed this by changing the speed of the arm from increments of 1 to increments of 6.

After I had made this simple code, my dad showed me how to add a delay to the arm movement, in order to add personality to the way the arm acted.

The simple version of the code is is pictured above.

I really enjoyed making this project since I had never done anything like this before. I had a lot of trouble on the coding portion since I had never coded an Arduino before, but I watched a bunch of helpful Youtube videos and learned some functions from my dad. This was a really fun project to make, and I can't wait to make one for my teacher Ms. Berbawy!