Introduction

This is my version of the Useless Box. I added a buzzer and now it can play tunes. I printed everthing with a 0.6 nozzle and used supports, but I think you can do without supports.

The box uses two mg90s servos. You could use the sg90s version as well. Printing all the parts took about 5 hours.

You can find the code for the Arduino Nano (or clone) here: 

https://github.com/Dawied/Useless-Music-Box

The code uses music from Robson Cauto's project "Songs for Arduino", thanks!

https://dragaosemchama.com/en/2019/02/songs-for-arduino/


Bill of Materials

• 1 Arduino Nano or equivalent

• 1 Nano expansion board

• 1 18650 battery

• 1 18650 battery holder

• 1 flip on/off swicth (for main power)

• 1 toggle on/off switch (for operation)

• 2x MG90s or SG90s 180° servos

• 1 Passive buzzer

• 8 M2*4 screws

• Dupont wires (for buzzer and battery holder)
  

Assembling

Use male dupont wires to solder on the 5V output of the 18650 battery holder. Place the main switch between the + of the battery holder and one of the V pins of the expansion board

Use the M2*4 screws to mount the expansion board and battery holder in the box

Fit male dupon wires on the buzzer and click the buzzer in the buzzer holder of the box

Fit the toggle switch into the hole of the lid and secure with the screws.

To correctly fit the fingers on the servos, connect the servos to the expansion board and run the code one time, this will put the servos in the resting position.

Now fix the switch finger making sure it stop a few millimeters before the back of the box. Fit the lid finger making sure it rests a few millimeters above the battery.

Fit the MG90 servos into the retainers

You can use a piece of filament for the hinge. The fixed part of the lid will snap into place on the box.

Connections

If you have any questions, feel free to contact me!

Enjoy!