Reminded me of the ferrofluid clock by Zelf Koelman (https://www.dezeen.com/2015/08/26/zelf-koelman-ferrolic-cloc...)

Though of course the mechanism is very different here.

> The Ferrolic is currently still in development, although the designer intends to make small batches available for pre-order, with each clock costing $8,300 (£5,300).

I fell in love and needed one right until I saw the pricetag. Beautiful clock though - thank you for sharing :)

The designer's personal site, and the clock site are both now gone, so I am assuming he never got to production stages... still an amazing idea, and an inspiration for anyone that would like to try building one on their own...

same, i judt don't have enough liquidity to afford such a clock

This is very koel!

Beautiful result. I always liked the use of ball bearings in design. It reminds me of the bradley timepiece, which is an analog watch that uses one: https://www.eone-time.com .

Love the design, though I think the noise it makes when updating the display would drive me crazy if I had to listen to it once a minute.

They used the cheaper servos for this build, understandably, but if you buy some more expensive ones you can probably make it nearly silent. This would also likely let you make the servos move faster and reduce the time it takes to update (and thus make noise) at the same time. I'd also consider maybe using solenoids to move the magnets in and out which could be completely silent then too, at the expense of needing some more current when engaging if you add some damping, just a little felt at the end of the rod. Then switch to steppers for the rotation and lifting the ball platform and you could likely have it completely silent.

You will quickly learn to live with it, just like with older mechanical (granfather's) clocks.

> completely mechanical

Well.

Nice. This suggests a similar mechanism for a larger display, where you have a board with a large number of holes and magnets to hold the balls, and a traveling write head that places them.

Are there small electromagnets available for sale that could do the same thing?

Before I looked at the details, I thought it was electromagnetically driven. Combine that with a power outage, and you’re hunting for little steel balls on the floor. But at least you’d know when the power went out, based on which ones are missing from the base.

I wonder, is it possible to make a magnet that's always on and uses power to switch it off? Kind of like how air brakes on trains work.

There are classes of relays that worked like that in old portable broadcast video recorders. Essentially a coil around a magnet and the coil was used to strengthen or weaken the flux with a pulse of current. The armature was spring loaded but not strong enough to release from the permanent magnet unless a pulse of "buck" current was applied.

Old timey stuff.

Yes, you add a magnet in the middle of the coil and actuate the coil with opposite polarity to cancel the magnetic field

Maybe, but I probably wouldn't try to use them for that. Instead I'd look into getting some kind of latching solenoid to move the real magnets in and out of position. That'd let you have it be silent (or nearly so) and not need to keep the magnets energized the entire time, reducing power usage. Then steppers for the rotation and platform lift

This is a cool project and an interesting design, but after reading the description I'm still not clear on how it actually works. How is it choosing which balls get retained each rotation when the top part is basically all fixed magnets?

In the second video you can see that the magnets in the top part move towards and away from the faceplate to release, retain the balls respectively.

I was surprised by this, as I assumed from the first pictures that it was going to be electromagnets. Seems like a lot of moving parts to do it this way.

Permanent magnets on servos won't lose their grip on the balls when power goes away.

*retain, release respectively.

Wow, this is awesome! Great concept and a beautiful result!

sweet project :-D

Cool clock, but the loud fart in stereo audio in the video stands out more to me