Mechanical-Digital Steel Ball Clock

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Introduction: Mechanical-Digital Steel Ball Clock

So I decided to finally learn how to use an Arduino and worked my way up to my very first project, a digital clock that is completely mechanical.

Enjoy!

Supplies

Electronics

  • (1) Arduino Nano
  • (2) PCA9685, 16-Channel 12-bit PWM/Servo Driver
  • (1) DS3231, Real-Time Clock (RTC)
  • (1) TTP223B Capacitive Touch Switch Modul
  • (33) SG90 Servo
  • (2) 20KG Digital Servo High
  • (1) Servo Signal Reverser
  • (1) 12V 6A Power Supply

Materials

  • Walnut Plywood, 0.125"
  • Walnut Veneer
  • Clear Acrylic, 0.120"
  • Carbon Steel Wire
  • Small Screws
  • Small Permanent Magnets
  • 0.25" Steel Balls

Equipment

  • Glowforge Laser Cutter
  • General Hand Tools

Step 1: Circuit and Code

Even though this is my first project, the circuitry was actually quite straight forward. Everything connected with each other through the SDA, SCL, ground, and V+ pins.

I wont go deep into the code either since a lot of it was learned from other sources, but it was pretty simple:

  • Each servo was controlled through one of the two PCA9685 boards. 7 segments per digit means 14 servos for hours and 14 for minutes. There are also two heavier-duty servos for rotating the housing, 4 for the lift, and 1 for the colon.
  • The time is kept and retrieved from the RTC.
  • I also wanted to play with a touch sensor so I used one to switch between military and regular time.

Step 2: Prototyping

Digits & Numbers

  • For each digital number, there are seven segments and each segment is controlled by a servo.
  • One of the biggest challenges was to pattern the servos in the best possible way so I could minimize the size of the clock as a whole. CAD helped with this.

To start I only made a single digit. You can also see the grooves in the lift where I originally intended for the steel balls to rock back and forth to align the balls in the right place. The clock would also change time by dropping all the balls first, but that got a little complicated. Probably a good thing though because the clock is already pretty loud and 100+ steel balls dropping every minute would probably get annoying.

Step 3: Design

Housing (Top Part)

  • Each servo is attached to the wire bent into a linkage. The wire holds onto the one segment for the number and there are 4 magnets for each segment. Now repeat about 28 more times.
  • The first layer with the magnets, second holding the servos in place, the third holding the electronics, and the backing last. Admittedly, its tightly designed and has poorly located electronics, but oh well.... :)
  • The sides hold the two 20Kg servos that rotate the entire housing to the load/unload position.
  • Note to self: dont use different materials to build. I wanted to have the clock to be mostly clear (acrylic), with wood showing. Working with various thickness materials that also have different kerf sizes when laser cut gave me a huge headache.

Lift (Bottom Part)

  • The lifter has 4 servos connected to help raise and lower the lift plate which holds all the steel balls in the locations of all the segments.
  • To raise the lift a simple rack and pinion design was used.

Legs

  • The 12V power comes though the bottom of the base up to the housing.
  • I was able to discreetly hide the wires in one side of the legs with a slot for the wires to move without getting pinched.

Step 4: Finishing Touches

Throughout the design I was very conscious of having two versions of this clock. One that looked like wood all around and when I removed the three covers you would be able to see all of the insides and the mechanism working. I realize now that I will always have it with the covers on, but I still think it looks pretty cool naked!

Thank you for taking a look at my first Arduino project and also my first project posted ever!

Make it Move Contest 2020

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Make it Move Contest 2020

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    25 Comments

    8
    Donald Bell
    Donald Bell

    8 months ago

    Beautiful and very clever. Some code and SVG files would seal my vote.

    0
    hemy03
    hemy03

    Reply 2 months ago

    Agreed. Something for someone to try since it is and instructions site.

    0
    TheQubit11
    TheQubit11

    3 months ago

    Wow I've never seen anything like it! Amazing and looks very clean and sleek.
    P.s. 4:20 was a nice touch :)

    0
    will.valentino
    will.valentino

    Reply 7 months ago

    On one hand I agree on the other I want to try and make it without knowing how. Love figuring out stuff and maybe it will turn out differently.

    1
    will.valentino
    will.valentino

    7 months ago

    Simple, beautiful, and genius.

    0
    Handy_Bear
    Handy_Bear

    7 months ago

    So subtle and beautiful! You really should consider turning this into a product, it's so mesmerizing!

    1
    Stevens Workshop
    Stevens Workshop

    7 months ago

    That's an amazing project, the end result is as beautiful as it is technically brilliant.

    1
    arthur.sutton5
    arthur.sutton5

    Question 8 months ago

    Very impressive as a 1st project. My only thought is that it would sell well if you had it in kit form. It would be bags of fun assembling but to build from scratch is a daunting task.

    0
    LeandroB53
    LeandroB53

    Answer 7 months ago

    Eu mesmo compraria,o projeto e muito muito legal!!!

    0
    diy_bloke
    diy_bloke

    8 months ago

    Great, especially for a first project.
    In spite of your description i still have no idea what the principle of this clock is. What do the servos actually move? Magnets??

    0
    Rob Salmon
    Rob Salmon

    8 months ago

    FANTASTIC - Beautiful on many levels!

    0
    enguyen021
    enguyen021

    Reply 8 months ago

    how cool thank you!

    0
    jgarciaforteza
    jgarciaforteza

    8 months ago

    I'm going to pile up on the kudos. Cool idea, beautiful results. Well done!

    10
    Honus
    Honus

    8 months ago

    This is fantastic. I'd love to see more photos and build details with the full code.

    0
    ajvdmeij
    ajvdmeij

    8 months ago

    Great idea! And brilliant execution.

    0
    Dr. BretR
    Dr. BretR

    8 months ago

    Beautiful design and great work. Wow!

    0
    msameer39
    msameer39

    8 months ago

    superb. Very unique idea .