[HN Gopher] Faceless clock makes you think twice about how it works
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Faceless clock makes you think twice about how it works
Author : Tomte
Score : 122 points
Date : 2022-11-18 19:14 UTC (3 hours ago)
(HTM) web link (hackaday.com)
(TXT) w3m dump (hackaday.com)
| thunky wrote:
| This reminds me of the "hubless" motorcycle:
|
| https://motorbikewriter.com/hubless-motorcycle-streets/
| SamBam wrote:
| Neat. I had figured the hour hand had a tiny gearing mechanism in
| the connection between the two hands. A magnet is a much simpler
| solution.
|
| An old acquaintance of mine designed and sold an awesome
| wristwatch that used two ballbearings attached by magnets. [1]
| Not only was it useful for blind people (it was a much better
| mechanism than the old watches with an openable face, which could
| get misaligned by touching) but it was also fun to play with, as
| you could spin the ball bearings around and they could get caught
| again by the magnet. The video of the person spinning the hour
| hand reminded me of that.
|
| 1. https://www.eone-time.com/
| justusthane wrote:
| > I had figured the hour hand had a tiny gearing mechanism in
| the connection between the two hands.
|
| They have a previous version that was exactly that:
| https://www.youtube.com/watch?v=XCOC2zNjWCg&list=PLAYNJqEoXT...
|
| The movement of the hour hand is pretty terrible though.
| munk-a wrote:
| Yea - I'd assumed the hour hand had some sort of dead-reckoning
| compensating gear on the joint in the middle of the clock
| similar to a south-pointing chariot[1]. I'm actually a bit
| disappointed they used magnets since it'd be so easy to mess up
| the orientation with a bit of otherwise benign interference.
|
| 1. https://en.wikipedia.org/wiki/South-pointing_chariot
| divbzero wrote:
| > _I 'm actually a bit disappointed they used magnets since
| it'd be so easy to mess up the orientation with a bit of
| otherwise benign interference._
|
| That happens to a fair description of magnetic compasses as
| well. I suppose that's why some compasses use a modern
| version of the south-pointing chariot (gyroscopes).
| netsharc wrote:
| I wonder if they used gears to move the hand clock, if it just
| needs to be rotating at a constant speed... I think so, 330
| degrees counter clockwise per hour? Since, as the minute hand
| does a full rotation, the hour hand needs to travel 30
| degrees..
| munk-a wrote:
| Sort of - you'd need to have some system for clock adjustment
| to fix for DST, clock drift and the like that would also need
| to be incorporated into the spin. So just a constant low
| powered spin counterclockwise wouldn't be quite the full
| solution.
| Alexmania wrote:
| Konstantin Chaykin built a watch similar to this called the
| Levitas, seems really awesome.
| https://chaykin.ru/en/watches/levitas/
| IshKebab wrote:
| I always wanted to make one of these with fully floating hands
| using invisible thread.
| plgonzalezrx8 wrote:
| Love the "no bullshit" articles that explain things quickly and
| clearly. A+ Work on this blog post.
| mortenjorck wrote:
| Projects in this space tend to be fairly niche, geeky proofs-of-
| concept with a Woz-like fun factor but little mass-market appeal.
|
| This, however, has plenty of both. With a little polish to the
| industrial design and a high-quality contract manufacturer, I
| could absolutely see this becoming a popular item in homes and on
| desks.
| ok_dad wrote:
| No, not everything needs to be turned into a product for the
| capitalistic machine. Let us have some fun without trying to
| make a buck off of it!
| [deleted]
| CobrastanJorji wrote:
| I'm sad that both hands aren't magnetic. It'd be much more cool
| if the whole hand assembly floated. I suppose the two sets of
| magnets might interfere with each other as they pass by. I wonder
| how far you'd need to separate them to make it work.
| CrazyStat wrote:
| Making stuff float with magnets is hard. You have to replace
| the permanent magnets with electromagnets and then have a while
| bunch of sensors and logic to drive the electromagnets. I can't
| see a way to make it work in a clock like this.
| CobrastanJorji wrote:
| Ah, I see. What about those cheap "floating globe" or
| "levitron" desk knick-knacks? Do those maybe only work
| because they freely spin, whereas a clock could not?
| CrazyStat wrote:
| They work because they have a reasonably large base and a
| reasonable stable thing floating. The clock hands aren't
| stationary, let alone stable, and since clocks are
| generally flat in one dimension you have pretty limited
| space to play with.
|
| The only way I've thought of to make it work would be to
| have a fairly large "hub" at the center of the floating
| thing, with the two hands coming out off the floating hub.
| But that would be much less visually impressive, I think.
| The hub would have to be large enough that the movement of
| the hands is relatively miniscule in terms of weight
| distribution.
| munk-a wrote:
| I think (especially considering the different needs for 6:28
| PM and noon) that you'd need some orthogonal magnets set up -
| have one set of strong magnets around the center of the hub
| to keep it in place while providing a minimal amount of field
| interference to the magnets driving the hands. I'm not an
| engineer but I think any solution that starts with trying to
| suspend a clock using magnetic forces applied to the clock
| hands is going to be incredibly complex and hour-minute
| cross-overs would be extremely delicate maneuvers considering
| how much of a raw magnetic field you'd need to be projecting
| just to keep the clock face floating in air.
| bee_rider wrote:
| Clever and elegant
| [deleted]
| [deleted]
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