3D-Printed Clock Tells Time With Gears

[ekaggrat] designed a 3d-printed clock that’s fairly simple to make and looks awesome. The clock features a series of 3d-printed gears, all driven by a single stepper motor that [ekaggrat] found in surplus.

The clock’s controller is based around an ATtiny2313 programmed with the Arduino IDE. The ATtiny controls a Darlington driver IC which is used to run the stepper motor. The ATtiny drives the stepper motor forward every minute, which moves both the hour and minute hands through the 3d-printed gears. The hour and minute are indicated by two orange posts inside the large gears.

[ekaggrat] etched his own PCB for the microcontroller and stepper driver, making the build nice and compact. If you want to build your own, [ekaggrat] posted all of his design files on GitHub. All you need is a PCB (or breadboard), a few components,  and a bit of time on a 3D printer to make your own clock.

52 thoughts on “3D-Printed Clock Tells Time With Gears

          1. Well, first of all it was intended as constructive criticism.

            As for why I don’t try it – the datasheet makes it abundantly clear that the internal oscillator will not be sufficiently accurate for a clock over extended periods and in different temperatures. If it were possible to make sufficiently accurate RC oscillators, nobody would use watch crystals.

          1. OK you are right. I did not want to be rude. But I was. Sorry for that. This clock really IS a beauty and you should spend some effort to make it as accurate as possible. Which you already said is going to happen. So sorry again for being unreasonably harsh.

      1. Well.. no. The datasheet [0, p25] says that the internal oscillator’s accuracy is +/- 10%, so expect more than 5 minutes per hour deviation. I wouldn’t use it as my alarm clock, even when calibrating it to 2% accuracy.
        32kHz crystal oscillators such as used in everyday clocks typically have an accuracy of +/- 20 ppm, 5000 times more accurate.

        1. well as i said i have had it working for a week with 3 minute error at the end of the week ( i was curious to see the accuracy )…. thanks for the behind kicking…. i will put the crystal in … HAPPY?

          1. There’s rarely anything anyone can say which will go down with everyone. That’s the way it goes in the comments-secion of HaD these days, or so it seems. Don’t get too worked up about it, it’s not worth the energy.

            I personally think it’s a lovely build: the clock looks good and a 3-minute error sounds like a pretty accurate clock for its part count.

          2. This is an amazing build, don’t let anyone bring you down about it. It’s interesting, well built, and imaginative. Keep up the good work.

            Just a suggestion: a printed clock face of some sort might make the clock easier to read, if you wanted to go that route. This is only a suggestion, not criticism.

        2. Part of it is the amount of resolution for the trimming, and part of it is to account for variation in process, voltafge and temperature (PVT). Then there is the Scotty fudge factor so you don’t toss out otherwise usable batches of chip and the usual CYA. In reality, you should be within +/-1% just from factory calibration as you are not likely to be at the corner cases for PVT.

          +/- 20ppm for a gear clock should be fine as it falls in the resolution of how you read it anyways. If you want to play with temperature compensation, those guys with the TI MSP430 watch managed to trim it down to a few seconds a year.

      2. This is a great build. excellent work. Can’t wait to get my printer next month to start making this clock. Ignore the 1st world complainers on the oscillator. This isn’t intended to be an atomic clock. a few minutes per week adds to its charm. Keep up the good work.

  1. Wonderful build! I like the colors and the construction!
    Of course there will be an inaccuracy with the built-in oscillator but I bet that [ekaggrat] already knew that before posting the project..
    What I wonder is how loud it is?

  2. That’s very stylish! Not surprised to see that [ekaggrat] appears to have an architectural background.

    Also happy to see this was described accurately, as “an ATtiny2313 programmed with the Arduino IDE”, rather than simply called an Arduino.

  3. Mm. how about a feature where you could position a laser etched round piece of acrylic in the center in one or two small acrylic extentions. That would be a freaky faceplate.

  4. That is one beautiful clock – amazing build!

    What CAD software did you design it in, that exploded diagram looks really good too. I’ll be adding this to my “to-make” list, thanks for sharing!

  5. This is the first 3d printed project on HAD that has inspired me to fire up the makerbot and try out!
    Awesome design, i can’t wait to have it ticking away on my desk, though after reading some of the comments I might try to experiment with a different oscillator…

    I was curious if you considered adding a second-hand ring to the clock, and if you decided not to include one, why not?

    1. i did make a mechanism to have a 3rd ring but it just made it bulky and the friction of the gear train was adding up.. Besides you don’t want a stepper motor going burr burr in the middle of the night..:)

      1. True about the stepper motor running all night. I’m sure adding a seconds-gear would require adjusting the design to use some other low power constant motor or other similar mechanism… like some sort of clock haha

        I fully understand the issue of gear friction, there’s obvious limits to what we can do with the tolerances of 3d printed parts. Even with just minutes/hours, awesome project, ekaggrat, thanks!

        1. no the micro controller is working in dumb mode… just pulses the motor at reqular intervals without knowing where the rings are .. so you turn of the clock it looses track of time…

          1. …but as tekkieneet suggests it might be an interesting addition to have a “sleep” mode, with the micro able to drive the stepper to a specific time. Hooked to a GY-521 and could wake on tap outside normal sleep times.

            Great design ekaggrat, thanks for sharing!

  6. Argghh. I’m running out of excuses to keep from buying/building a 3d printer. Very cool & if you want to *really* annoy people, just run it via an old synchronous motor like a 70’s(ish) flip clock

    Now suddenly, I see a printed grandfather flip clock clacking away the mins

      1. Sadly, no sources of dxf/stl/?? that I could find. Amazon and company list flip clocks that could be used as donors/models of the drivetrain.

        to make things worse, I was just contemplating woodFill/Laywoo-D3 vs “normal” plastic colors contrasting with local red cedar open “frame”. Then there’s always steam motif w/the metallic filaments. (too many ideas and too little skill, sorry)

  7. I love this concept. If I had access to a laser cutter, then clear acrylic would be my material of choice, with perhaps transparent hands with black dots and tiny luminous circles on the tips and some carefully placed LEDs for subtle illumination.

    Having said that I love this design, and the choice of colours. As for accuracy… the nay sayers can use their smartphone, laptop, wristwatch, TV…. you simply can’t get away from millisecond accuracy these days.

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