A Nested Gear Clock

One of the most common projects we see here at Hackaday is a clock. It could just be that we as humans are fascinated by the concept of time or that making a piece of functional art appeals to our utilitarian sense. In that spirit, [Alexandre Chappel] set out to make a large mechanical clock with complex gears.

The initial design was made in Fusion360 over a week and then in a somewhat bold move, [Alexandre] started up the CNC and cut all the parts out of valchromat. The basic idea of the clock is that the numbers move on the clock, not the hands. So the clock should show 10:25 instead of moving hands to the 10 and the 5. Most of the clock is made of up stacked gear assemblies, geneva drives, and many bearings. A single stepper motor drives the whole clock, which [Alexandre] admits is a bit of a cheat since trying to add springs and an escapement would add complexity to an already complex clock. He did have to adjust and recut a few gears but most of the assembly came together nicely. Some 3d printed numbers dropped into the CNCed slots offers much-improved readability.

A few problems became apparent once the system was together. The numbers don’t quite line up perfectly, which is unfortunate. He mentioned that tighter tolerances on the gears would likely help there. A fatal design flaw on the smallest disk became apparent as it needs to turn a sixth of the circle whereas the outer circle is just turning a tenth of the circle. Mechanical advantage isn’t in [Alexandre’s] favor and the stepper skips some steps and it slowly makes its way towards the next second digit of the hour.

If you’re looking for more beautiful artistic clocks, why not check out this circuit sculpture one?

11 thoughts on “A Nested Gear Clock

      1. Oh … your “being shouted at” level is apparently pretty low :-)

        Compare this to “Jack Septiceye” (Gaming) or “Spectre Sound Studios” (Audio/Recording) or even “AvE” and this is at a pretty low shouting level.

        I guess it’s a way to stand out on Youtube … I think in every niche there is at least one “shouting guy”.

  1. This looks great. I like the idea behind it… moving the numbers instead of the hands. Reminded me of a clock my great aunt had in the 60’s where the minute and hour hands were mounted to two clear plastic disks and the clock mechanism in the base rotated the disks to indicate the time instead of direct driving the hands. You could see through the clock which fascinated everyone. I think it was called a Golden Hour clock.

    1. Yes I remember those and I looked closely then at one. There was only one disc and a bob of gears hanging in the center that divided down the minutes to hours. I guess that flipping the hanging gear-set over once would do for the time change twice a year.

  2. My Datsun 720 diesel pickup had a Geneva gear.
    It often failed to allow the starter solenoid to engage.
    I got pretty handy at hooking up a Remote Starter Switch in the dark.

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