Laser cut clock reminds us of a Spirograph

[Brian] from Louisville’s LVL1 hackerspace sent in this laser cut gear clock that’s almost unlike any other clock we’ve seen before. [Brian] also put up a wonderful Instructable for his build.

Since LVL1 got a better laser cutter a lot of neat projects have been piling up. [Brian] based his clock around two cheap stepper motors driven by a freeduino. A chronodot was used to keep accurate time. Making the gears, though, presented a few problems. While prototyping the gear clock face, it was apparent that the numbers should be oriented along a line coming from the center of the gear. The prototype also used 100 teeth and that didn’t translate well into a clock design. [Brian] designed the minute gear with 60 teeth, and the hour gear with 144 teeth so that each tooth would equal 5 minutes.

[Brian]’s clock is functionally similar to this $2500 gem, and certainly much less expensive even after the cost of the laser cutter is taken into account. Of course, the Spirograph clock keeps track of minutes so it may be worth upwards of $5k.

19 thoughts on “Laser cut clock reminds us of a Spirograph

  1. I saw this the other day and realized that, with the right gearing calculation and combination of stepper motor and a simple stepper IC, the Arduino wouldn’t be needed at all.

    You could use the 1pps output of the ChronoDot to generate a temperature-compensated accurate pulse train which you would provide to the stepper driver IC. The IC would rotate the motor at a precise continuous rate. Now you need to settle on a motor step count and ring gear ratio that rotates the ring once every 43200 pulses.

    1. The Arduino is also acting as the stepper driver, although dedicating a separate chip to the job and eliminating the Arduino would be a potentially cheaper solution.

      Of course, then you couldn’t do neat tricks like use the smaller gear as a date or day-of-week counter.

  2. … or you could forgo all this BS and just divide down the line frequency from your supply (divide by N counter) to get 1 pps. You’d be surprised at how accurate this method can be.

  3. does anyone else see the problem with the bike chain clock?
    yes, thats right, the $2500 price tag!
    i have a old gear motor based clock, stays accurate due to line frequency, i dont see why it would cost so much considering i doubt its any more complicated
    for that matter…
    WHY CANT CHARIZARD LEARN FLY?!

  4. Great comments everyone! It is so exciting that people are interested in my project. I really thought it was an interesting thought to take the arduino out of the picture and replace it with 7400 chips. I also liked the middle ring being day of the week. With the stepper/ring system you can do just about any type of repetitive time keeping. That is the fun part about making a project like this… I get comments of things I never thought of! Thanks everyone! Brian

    1. Funny, I like the burned look. Makes it more alive IMHO.

      And instead of saying something is awful you could also give tips on how to improve it.

  5. Very cool, and the resemblance to the Spirograph is cool as well. Spent many of my childhood hours playing with Spirograph toys…

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