I overengineered a spinning top [video] | Hacker News Reader

I overengineered a spinning top [video]

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For a real spinning top over engineered https://youtu.be/QLTsxXNekVE?si=S31kpZQHiYlUSedx

Thank you! This is what I really wanted!

It's fascinating that you can get to the level of atomic material properties as a spinning top hacker. Diamond seems like it'd be the obvious winner, if you could somehow get a perfectly polished and smooth surface.

I'd love to see a small Prince Rupert's drop for a tip and a ruby/sapphire spinning surface - you'd need to make a ton of drops, probably, but having a round, nearly spherical contact geometry and super smooth surface seems like a winning combo.

Until it wears just a smidgen and explodes violently!

Thanks! I came across http://www.pocketwatchrepair.com/how-to/jewels.php recently, hadn't realised the jewels weren't for aesthetics.

Link with spyware removed: https://youtu.be/QLTsxXNekVE

There is a Japanese show that made a Scientist vs Engineers version to build the best Spinning Top: https://www.youtube.com/watch?v=-q-hcidtjiM

Awesome!

This rules

The entire "Supreme Skills!" series is amazing. Highly recommend!

I saw this and, while interesting and impressive, this isn't really a spinning top. It's a gyroscope. I was hoping for a real like "I cast metal into the perfect shape that I physically derived somehow to last as long as possible" or something similar not just "I put a motor in a case and it spins"

https://youtu.be/QLTsxXNekVE?si=S31kpZQHiYlUSedx

your link has a "si=..." tracking parameter

Freaked me out for a second and had to double check that my tablet comes with a stop watch without having to download an app WITH ADS!!!!! Does he earn money for displaying these ads in his video too? I find it hard to believe that a content creator with sponsors is forced to use an ad supported app. Something about it being a stopwatch really just adds the cherry on top

I wonder if he wanted it to be bigger? The stopwatch on iOS doesn’t quite fill the screen as the one he used does.

Then use $1.99 from the sponsors to remove the ads????

Later in the video you see a clearer picture of apparently the same tablet and timer app, and no ad.

I saw what I thought was no ad, but you could still see the little widget in the upper right hand corner that still revealed where the ad would appear like when you manually click close ad on a website.

Not everyone wants to spend 2$ on a stopwatch app they can use for free and will only use it once.

That's part of being a content creator. Producing content has expenses. When you cheap out on it, it looks obvious and people will comment. Hi

People are significantly biased not to pay for computer things. Except for Apple users. Any mobile developer knows Apple users will pay for things a lot more than Android users.

That's why smart people use Android.

Ugh, let me get my eyes returned from rolling so far to the back of my head. As if Android doesn't have adware apps.

No, smart people use Android because you can install apps on it that the manufacturer doesn't approve of.

For now. When that changes soon, smart people will start having two phones, one of which runs Linux or GrapheneOS.

Excellent!

At around the end of the fidget spinner craze I thought "but what would it take to make it spin by its own?" And it turned out, not much. Just put one magnet at each of the three ends, and have some pulsating magnet near it (next to it, or under it hidden in some kind of base), and there! you have a basic electric motor that seems entirely magical.

It was a really fun experiment; I even toyed with doing a small production run but by the time I was almost ready the craze had passed.

Related, here's a globe that uses the earths magnetic field (an a little solar panel within) to spin "forever"!

[1] https://www.youtube.com/watch?v=U-NII1RdlcQ

It's been done. https://youtu.be/oAxQQyURMPQ

Reminds me of this little top, which actually works quite well: https://limbo.top/

man i get advertised to for these things NONSTOP. IMO it's cheating to call it a "top" but stick a motor in it to make it work.

Saw this last week, really enjoyed the tenacity in problem-solving!!

Did make me wonder if you could build a solid state one using well-timed pulses through an electromagnet that provide torque through the field interaction with the earth's magnetic field.

Not much torque available there obviously, but on a per-revolution basis you don't need much.

The physics of magnetic torquing maybe could probably work in most if not all locations on Earth for a sufficiently small and power dense vertical top that spins sufficiently slow. Want the smallest possible local dot product of gravity vector and magnetic field for an ordinary top (without considering "sideways" tops), which may lead to better performance in some locations on Earth (could map this with e.g. IGRF). 3D field actuation would be beneficial to allow higher efficiency and longer periods of actuation around the window where the Earth's magnetic field is maximized in the spun plane, while minimizing imbalance: this actuation timing is probably the only strategy that would make practical sense for most of the magnetic power, because you will need to take a break once in a while for sensing. Another practically difficult part would be avoiding on-board soft iron noise in magnetic field, because higher spin speed would require the device and environment to damp out the device-induced magnetic field at a higher minimum rate to afford any budget for accurate sensing of the background field during the "off"-time. That is: sensing trades with spin speed because it takes non-zero time and requires a stable environment.

To implement this, I think you'd first want to test in a controlled environment with a larger magnetic field and then gradually turn down the applied field until it is Earth-like. I am honestly unsure whether you could practically get there, so earlier I used the words "maybe could", but humans are crazy so I appended the "probably".

This would be a fun YouTube video to watch.

here is a new engineers supersonic trebuchet project

https://hackaday.com/2021/12/01/supersonic-projectile-exceed...

I like it, but part of me thinks that spinning tops should be without IC and batteries. I don't mind some steampunk clockwork mechanisms though.

I love projects like this. Taking something trivially simple and asking "but what if we really optimized it?"

The material science discussion in these comments is fascinating. Never thought about how the contact point geometry matters so much. Diamond tip makes intuitive sense for hardness, but then you need something it can spin on without scratching...

An interesting fact is that spinning tops are extremely ancient toys.

For instance, a spinning top is already mentioned in the Iliad of Homer, where he compares the rotation of a certain warrior after receiving a very strong off-center strike with the rotation of a spinning top ("strombo-" in Ancient Greek).

This is fun, well done. Quite a performance to reach 2 hours on that little battery. Perhaps Euler disks are next?

> Quite a performance to reach 2 hours on that little battery.

Never perfect a game something to its theoretical limits, It stops being exciting.

https://youtu.be/0Yubn6P5DUw

My mind immediately went towards Battlebots when I saw electronics getting involved. I wonder what else would need to be done to make this steerable over RC? There may be a lower weight class where some nicely CNC'ed 'Phantasm Orbs' can score reasonable points.

This already exists- there's a class of robot called "meltybrains" which spin the whole robot using one or more wheel, detect the speed of spinning with a gyro and modulate the speed of the wheels at different points in its' rotation in order to create translational movement. Since they effectively put all the weight allowance into the "weapon" they can be very effective. The additional complexity means that they are hard to get working reliably in chaotic combat conditions. A team called "Project liftoff" had some serious success though.

I saw Project Liftoff in person, that little death-frisbee? Looked like they have two points of contact with the floor, which is probably just better design.

And now that I think a bit further, I might just be imagining a more complicated version of one of those crabwalk spinny metal ones..

Meltybrains are still wheeled robots even if they use the wheels in a novel way.

If you could develop a self-starting top capable of remote controlled translational movement you would get non-wheeled weight bonuses up to 2x in most competitions.

Well: while measuring spinning durations of different spinning tops one should apply the same strength: not easy if done by hand

I am curious:

* will spinning *direction* (clockwise, or anti-clockwise) effect spinning duration?

* and being in Northern Hemisphere vs South Hemisphere (Coriolis effect)?

Coriolis forces appear only on objects that have a translation motion relative to the Earth, and which also has a direction distinct from that of the rotation of the Earth, i.e. either a north to south (or reverse) or vertical motion.

If the axis of the spinning top is stationary relatively to Earth, there are no Coriolis forces.

For a big spinning top, there could be non-negligible periodic Coriolis forces acting on the periphery of the spinning top, but they would be compensated by the rigidity of the top and in any case their average over a complete rotation of the top would be null.

Guinness book of world records lists a 7+ hour unassisted spin of a wooden top, and a mechanical-assist (like this one) of 41+ hours

How long would a better battery go here?

I'm curious what the jump from 2-> 40+ hours requires

Vacuum chamber?

No doesn't appear so. Seems to be just in open air. They've got a kickstarter done for one that does 6+ hours

Guess it's cnc milled, maybe that's part of it. Increase mass of the thing? Idk

he is also using development boards wired together rather than a custom pcb. there's a good chance the choice of passive components, removal of unneeded components, and better optimized power converters can improve the design.

These would make great pomodoro timers.

Entertaining, but holy cow that music distracts from the content.

this guy is super great but wow do the juvenile sexist comments he makes (over and over again, tripling down on them) detract from the overall value of the video. Would female engineering students really appreciate all that? I think not

As a male this turned me off too. I didn't like it, and it really distracted from the overall very cool thing.

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