5 ms·

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

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 4y ago
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 4y ago
  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 4y ago
    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 4y ago
  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.
daxfohl 4y ago
IIRC there was a rule from E and M class saying it's impossible to contain something using static charges alone. So presumably you'd need some high frequency sensors and feedback mechanism just to keep it stable. But I guess once you get that then moving it with time might not be that much more difficult.
- daxfohl 4y ago
  Nvm, that rule only applies to point charges, not rigid objects. So for this, the whole problem is hard.
- IIAOPSW 4y ago
  Also, you don't need feedback per se. Just a rotating field will do. This is how ION traps work.

CrazyStat 4y ago

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 4y ago
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 4y ago
  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 4y ago
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.

daxfohl 4y ago

IIRC there was a rule from E and M class saying it's impossible to contain something using static charges alone. So presumably you'd need some high frequency sensors and feedback mechanism just to keep it stable. But I guess once you get that then moving it with time might not be that much more difficult.

daxfohl 4y ago
Nvm, that rule only applies to point charges, not rigid objects. So for this, the whole problem is hard.
IIAOPSW 4y ago
Also, you don't need feedback per se. Just a rotating field will do. This is how ION traps work.