Hi, my name is Ortwin.... I am sure I can learn a lot from you here, and maybe I can even contribute something.
Welcome to the forum Ortwin!Correct, I am in Germany.
Are you in Germany? Or perhaps Austria?
Wow! That's a long time for a brass Quark top! More than I have achieved with my tungsten Quark!
I love the magnetic levitating tops you have made. I need to try a sphere on one of my commercial Levitrons. You also gave me the idea on how to spin a throw top using the homopolar motor design.
I saw the artistic tops of Iacopo, I admire his record spin times and have learned a few things already from his videos.Most of his tops feature that recessed tip design. That is great, but not what want in tops I like to play with. Still, inspiring work!Hi, my name is Ortwin.... I am sure I can learn a lot from you here, and maybe I can even contribute something.
Welcome aboard, Ortwin! I'd say you just contributed some very intetesting videos. And I look forward to learning more about maglev tops from you.
Our resident maestro of long-spinning finger tops is Iacopo Simonelli, forum screen name Iacopo -- and not just for his spin times, which in some cases approach an hour! His tops are also carefully engineered and exquisitely crafted works of kinetic art.
I'm interested in all aspects of top design. Spin time isn't everything, of course, but if I had to name some of the more important influences in finger tops, they'd be air resistance, center of mass height when vertical, axial moment of inertia, and stem diameter, in roughly that order.
How do you think stem diameter is a important parameter? Is it its relation to the maximum rpm one can achieve?
The Quark top was very unbalanced to begin with. The washers supplied were no enough to correct this. I had to fill one of the three holes completely with lead an leave another one almost empty to get a balanced top. ......This time around I could not get far beyond 13 minutes and I discovered there are more issues with this Quark top. The metal ring is not perfectly aligned with the black plastic inside, there is an angle that can be observed with the laser method and you can even feel it with the finger. Also the tip does not look perfectly smooth under a microscope.Mine required several O-rings to balance, but that was enough. I never looked at the tip with a microscope.
Magnetic levitating top: What is the size of the magnetic sphere you want to spin? You are aware, that you need a levitation base where you have a means of changing the magnetic field, since you can't play around with the weight of the top much, right? Anyways I would suggest you try to get a magnetic sphere spinning first far away from the levitron base. This can be frustrating in itself until you first succeed. I can give you helpful hints of course, if you want me to.
But with the popularity EDC tops (https://www.ta0.com/forum/index.php/topic,4122.msg42521.html#msg42521), you can now get higher duration tops from many manufacturers (2019 Texas TopCon (https://www.ta0.com/forum/index.php/topic,5710.msg63595.html#msg63595)).
Magnetic levitating top: What is the size of the magnetic sphere you want to spin? You are aware, that you need a levitation base where you have a means of changing the magnetic field, since you can't play around with the weight of the top much, right? Anyways I would suggest you try to get a magnetic sphere spinning first far away from the levitron base. This can be frustrating in itself until you first succeed. I can give you helpful hints of course, if you want me to.
When I wrote that, I wasn't thinking about the need to adjust the weight. Yes, that would be a big problem. Anyway, I need to order a bigger magnetic sphere as the ones I have are very small (4.75 mm). I did try yesterday to spin an aluminum top with a steel tip hanging from a magnet, using the homopolar motor idea, but failed. I need to experiment more.Use thick cables like the ones used for big speakers. You have a few amps flowing there from a 1.2 V rechargable battery. The cable going to the plate is best soldered firmly to the plate. The plate should not be solid metal, the eddy currents would slow the top down. I use a circuit board.I would start with a sphere of about 20 mm in diameter, the 30 mm ones are harder to accelerate and control.
...what is a good time these days. (I know Iacopos records from this forum)
I see some possibilities to balance it if needed. Hope to get past the 20 minutes with this. I am really surprised that I find none that offers balancing with setscrews or something.EDC's made of one piece of metal machined on a numerically controlled lathe should come out perfectly balanced, so no need for adjusting screws.
What is there on the market you would recommend for high spin times?
Also I could not find results from competitions like "2019 Texas TopCon" listed on web pages to give me an idea of what is a good time these days. (I know Iacopos records from this forum)
I saw the artistic tops of Iacopo, I admire his record spin times and have learned a few things already from his videos.Most of his tops feature that recessed tip design. That is great, but not what want in tops I like to play with. Still, inspiring work!My top from Iacopo has an external tip. It came with a base for easy spinning but he later sent me a replacement tip that holds a ceramic ball. With that tip it's not too difficult to spin on a table at moderate RPM's without scratching the surface. Of course, if you are trying to get maximum speed, it becomes difficult to do.
My top from Iacopo has an external tip. It came with a base for easy spinning but he later sent me a replacement tip that holds a ceramic ball. With that tip it's not too difficult to spin on a table at moderate RPM's without scratching the surface. Of course, if you are trying to get maximum speed, it becomes difficult to do.
But what about stemless tops?I saw a video here in the forum (actually I think it was in a post of yours) where a top made from a coin spun for 12 minutes.
The trade-offs involving AMI, starting torque, scrape angle, critical speed, and spin time are especially tough. Again, Iacopo's lead is a good one to follow, as a longer stem gives finer tilt contol during spin-up.
That means you can deliver a given starting torque at a smaller ground clearance, scrape angle, and CM height without scraping.
If the density of the stem material is low, lengthening it will have little adverse effect on CM height or the ratio of transverse to axial moment of inertia. Hence, critical speed's unlikely to increase and may even improve.
When the trade-offs are played just right, a longer spin time with no scraping can be achievable. Practice also helps, to a point.
How do you spin up your Amazon purchase?
Not sure that was the video link you intended. You mean like this, with the symmetry axis more or less vertical?
If so, what was your question again?
I am really surprised that I find none that offers balancing with setscrews or something.
From a spin-time perspective, this beauty does almost everything right:
The longest spin at my knowledge with a single twirl and external tip is this one, (49 minutes), but other owners of the same top seem to have quite lower spin times... In any case this is a good top for long spins.
From a spin-time perspective, this beauty does almost everything right:
Thank you, Jeremy ! By "almost everything" you mean that there is something you think it could be made better... ?
New ideas are always welcome.
That is the information I was looking for Iacopo, thank you!That helps me set my goals in this fields:
> 15 minutes with a self built top (probably stemless) - short term goal
> 20 minutes with commercial top (maybe with optimization) - mid term goal
> 25 minutes (a top a friend with a lathe helps to buid) - long term goal
> 30 minutes (getting lucky) - lifetime goal
But, in retrospect, I can say that this was one of the purchases that made me most happy.
my experience with tops of many shapes and sizes makes me think that a smaller copy of Nr. 30 might stay up longer.
Of course, this does not count for a record. The "top" does not topple and spins down to zero. Therefore it's not working as a real top, at least not towards the end.
What is the Kemner top made of? The stem and rotor look to have been cut from a single piece of aluminum or satin-finished stainless steel.
What about the tip? Guessing all those long sleeping spins have worn a small flat at bottom dead center.
"Due to the inherent issues with tungsten the top may have some flutter near the end of the spin even after being balanced."
Thanks! Wonder what that statement from Kemner means? Do tungsten's high density and difficult machinability limit the ability to fine-tune balance, centering, or alignment?
See, that is what I mean: if there would be setscrews for dynamic and for static balance one would have a chance to correct this in a more elegant way. Also a ring on the upper surface prepared with regard to be useful for "the balancing by laser" method would be nice in these tops that are meant to spin for a long time. I can't believe all those tops are perfectly balanced and still show such a big difference in spin time.Thanks! Wonder what that statement from Kemner means? Do tungsten's high density and difficult machinability limit the ability to fine-tune balance, centering, or alignment?
..., then they balance it making holes under the top, so, while correcting the static balance, they may cause a bit of dynamic unbalance ...
... Have you considered to buy a lathe ?
With the difficult machinibility and all of tungsten, why not using something different? It does not have to be gold, platinum is a lot cheaper these days and also it has a higher density. I do not know about machinibiity though. Don't you think you can easily find a collector amongst your customers willing to finance such a project?
Of all those Kemner tops for example with times from <25 minutes to >40 minutes, do you know if the same person had two spinning on the same surface for very different times? Or could it also be on the other hand that different persons use different bases that also could account for a part of the differences? I recall with my Euler's Disk I got far better times when I glued my base to the floor......
Burning desire department: Gee, wish Iacopo hadn't mentioned uranium. Now I want a U top! Yes, even depleted U has some residual radioactivity. And U is both combustible and very hard to put out. So a lead-lined fireproof storage bunker well away from the house might be in order. >:D
Jeremy, you envision a small version pf this bicycle wheel with a stem ?
Or maybe without a stem? There must be some crossover point (regarding the diameter) where a top is spinning longer when spun with two hands and without a stem as opposed to the same top with a stem that brings up the CG higher.
Also my "Amazon purchase" comes to mind:
(https://i.ibb.co/Jtyq1GF/amazon-purchase.jpg) (https://ibb.co/Jtyq1GF)
Only one spoke. The Spoke (a streamlined version of course) and the ring inside the platinum flywheel could be 3D printed .
The tops you show in your pictures look great. Do you get your inspiration more from Star Wars or rather from 2001: A Space Odyssey ?
That "modular building system" results in quite large tops, right?
It has been my guess for a while that a platinum wheel with 3 needle spokes would have the absolute longest duration possible.
For the spokes, note that a circular rod moving sideways through the air generates a lot of drag -- partly due to its complex turbulent wake. Best for the spoke coming behind to see as little wake as possible.Think of how racing bicycle frames have evolved.
Probably I am just picking the set of rules so that I have a niche where I think I have the chance of achieving something. Of course that process can look quite arbitrary. Anyways, at the moment, ..... no recessed tip, only one twirl, only one piece... is what I personally like to go for.[/font]I think your rules are very reasonable and among the most logical to have for a record, so not too arbitrary.
Now that was an inspiring remark for me! Especially the word "needle". I remembered these pins with the yellow glass head my wife has in her sewing set. When I looked for them I also found these white plastic rings - they are used for curtains or something.That's a nice homemade top! It reminds me the exclamation point top (https://www.ups.com/WebTracking/processInputRequest?tracknum=1ZYR20670496638309) minus the stem.
It reminds me the exclamation point top (https://www.ups.com/WebTracking/processInputRequest?tracknum=1ZYR20670496638309) minus the stem.
But I don't think that a single spoke top could be made balanced and rigid enough to go for a record. I think 3 spokes would be the minimum.
Another Curtain Ring Top - two spokes
Actually this "curtain ring top" thing is becoming a little series of presentations of concept tops.... I hope you don't mind too much that I do not put much time and effort in the presentation and videos. I think the concepts can be understood from these and that is what I want to share at this point.
@jeremy: great looking top in chains!
When I first watched the video, I thought the the octagon was going up and down a few times du[size=78%]ring the same spin. Okay this is not the case, but is there some type of top that also shows some deterministic chaos in some nice clearly visible way? Probably you just have to send a link to a video of one your Lego tops.[/size]
I just thought the humble pendulum, being one the guinea pig of physics, has some pretty nice chaotic cousins. What about the top or the gyroscope, another guinea pig of physics? Do you know of any versions that display chaotic behaviour?
...We might have some misunderstanding going on here, not sure though. In these tops there is no loose or moving part or something like that when it is finished and ready to be spun. The string is tensioned , like on a guitar. Well maybe not with not quite that much pull, but it is pretty stiff now. The self centering of the bead happens when tension is put on to the two strings.
I have a number of self-centering tops with various moving or loose or floppy parts onboard. Still trying to understand exactly how it works.
Is the video age-restricted to keep your daughter from finding out you're taking her stuff?
Curtain-Ring-Top Nr. 1.5 - colon top
Besides the commercially available "exclamation mark top"and the PERIOD top (curtain rin top nr. 1) this "colon top" is the third punctuation top I know of, can you think of any other ones?
Love your ideas for making tops out of household and hardware store items. ...Yesterday I found this nice quick build on YouTube that beats me by far!
Curtain-Ring-Top Nr. 8 - 4 spokes, tungsten carbide tip, wind up starter includedThis is an improved version, but it has no Curtain-Ring, so it ends up here.
Are members banned from the forum if fidget spinners are visible in their posts?
You're going totally modular on us ortwin! Love it!Well I figure once we found out the playful way what works better and maybe what works best, we can still think about how to put it together in a nice way without the chuck.