Curtain Ring tops + follow ups

[ortwin]

Preview of LaBrassBanda

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[url=https://ibb.co/FVzk547][img]https://i.ibb.co/FVzk547/Preview-of-La-Brass-Banda.jpg[/img][/url] 

LaBrassBanda is not back yet, there was a misunderstanding and some of the many threads I asked for did not run the direction I wanted them to run, so it will be a few more days until I can play with it. The general look will be like this picture. The red plastic that makes the knurled stem is the cap of a tube of (Italian) tomato paste.

[ortwin]

LaBrassBanda is here!




Some of the newer details can be seen in the big picture, the legend describes their function.
As I said in another post the spokes are 0.5 mm brass pins/needles. They are inserted from the one side through a hole in the hub that is large enough for the pinhead to pass. Then before the needle almost reaches the opposite side of the hub, the hole becomes smaller so that only the bin can pass not the pinhead. The pin can rotate in that position.
After the pins of the correct length were fed through their respective hole, the tip was soldered into holes in the center of grub screws. Then the whole thing could be assembled. All this work, including the fabrication of the adapter and all the threads in the ring, was done not by me but my friend Mr.H. following roughly the ideas I gave him.

Three of the spokes go to the lower end of the hub, the other three spokes to the upper end. This allows not only to center the hub but also to adjust the direction the axle is pointing. This is one advantage over the three spoke design of "Junior Brass Band".
Soooo, now I have a lot of screws to play with but no good strategy how to reach the best dynamic balance possible. I did not take the time yet to seriously balance this top (too busy with intuitive precession stuff ). Up to now I arrived at the point where it spins for 22 minutes before scraping the pedestal free base. Again I am confident that I can break the half hour barrier with this setup before Marines Festival.

[ta0]

LaBrassBanda looks like it means business!

Again I am confident that I can break the half hour barrier with this setup before Marines Festival.

Do you mean that you going to Marines?

[ortwin]

...
Do you mean that you going to Marines?

What can I say, Jim invited me to come and set up a table with some tops.
I feel very honored!
So I accepted the invitation. Hopefully the corona situation will allow it to happen.

[ta0]

...
Do you mean that you going to Marines?

What can I say, Jim wrote invited me to come and set up a table with some tops.
I feel very honored!
So I accepted the invitation. Hopefully the corona situation will allow it to happen.

Oh, my! It's crazy, my spintop travel budget is going through the roof, but I might have no other option that to also come to this one!

By the way, I updated the list on the festivals page: https://spintops.org/fests/
(but I have not yet included any in Asia)

[ortwin]

...my spintop travel budget is going through the roof, but I might have no other option that to also come to this one!
...

Marines is only beginning next year! So you will still have most of the budget available for 2022!
Es freut mich, dich dann persönlich zu treffen!

[ta0]

Es freut mich, dich dann persönlich zu treffen!

Ich würde dich auch gerne zu treffen.

Mareike Schwarz, Mermouy's friend and top player, should also be there. I guess at least I'll hear some German

[ortwin]

Iacopo, I copied your reply from the other thread to this one so we can discuss (later) the things related to the ring tops here without having to go about the design problems in my tops in the thread of your beautiful tops.

Two further exquisite Simonelli tops! Congratulations Iacopo!

Thank you, Ortwin !

I also like it that you present this new balancing method.

The new part of the method is the use of the laser pen.
I have been using this method for years, both for static and couple balance. I explained it in a video on my YouTube channel six years ago, a bit more in detail.

With your statements that static balance can best be treated at low speed and couple unbalance at high speed and so on, I am not completely happy. It might be perfectly valid for practical purposes especially with your type of tops with the really sharp pointed tip and if you can statically balance it almost perfectly at low speed first - but if I consider my tops with the 0.5 mm tungsten carbide ball tip things could look different.

I haven't much experience with ball tips but I don't see why it shouldn't work with them, especially with a 0.5 mm ball tip, which is so little and not so different from a pointed tip.
When I used this method with tops having an external 3/16" tip, it worked.
I understand that it is more difficult to use the paint and brush if the top, because of the ball tip, walks on the spinning surface.
Having a short stem, like in your tops, too, doesn't seem to help.
But the difficulty to detect the direction of leaning of the unbalanced top doesn't mean that the method is wrong.

..if you can statically balance it almost perfectly at low speed first..

This is desirable but not always possible, and not so much important anyway.

In the case of these my latest two tops, due to the glass balls, which are empty inside, and with uneven thickness, when I tried to balance them, I found that there was a lot of couple unbalance. For this reason I added the vertical screws, which were not part of the design in the beginning.

After having added the vertical screws, I started balancing the tops at low speed, using only the horizontal screws, until the tops seemed balanced and they didn't wobble anymore. Then I spun the tops at high speed and they didn't appear balanced anymore, there was evident wobble, I corrected it using only the vertical screws. After an important correction of the position of the vertical screws, it is normal that the static balance does not appear so accurate anymore, so at that point I had to check again for the static balance, there was a bit of wobbling, I corrected it with the horizontal screws at low speed, and at that point the overall, (dynamic), balance was good.

You have your top with all those screws, both horizontal and vertical, it is perfect for to experiment with these notions, if you want.
For example, you could adjust the horizontal screws so to make the top statically unbalanced on purpose.
Then you could move the vertical screws and produce a couple unbalance with opposite direction to that of the static unbalance, so that the top could spin apparently balanced. I can show you in which direction to rotate the screws, if you want.

If you try it, you will see that you will be able to make the top to spin apparently balanced, in fact, but only at a certain speed.
Above that speed, the top will wobble, leaned towards the light side, dominated by the couple unbalance.
Below that speed, the top will wobble, leaned towards the heavy side, dominated by the static unbalance.

[ortwin]

....

I miss your experiments for longest spins, I followed them with interest, and your space station tops were great !

Again I copied this comment from you to this thread because it should not mess up your impressive world record thread.


But you are right Iacopo, I am not very active in the endurance tops experiments lately. At least not to the extend that I could report anything new really.
After I reached that goal of going past 30 minutes with video and spin decay curve and all, my motivation was definitely not as high as it takes to make further progress.
I still have the goal to go past the 30 minutes on a base without pedestal with a single finger twirl, but the first attempts with the ideas I had to reach that goal did not work as well as I hoped: The very thin spokes were not as stable as they should be, the soldering that fixed them to the grub nuts came lose a few times. Since I can't repair that part myself that is a problem.
The other idea that came from Bill Wells, using the vibration sensor of a cell phone for the balancing process, did not work as well as I hoped with the apps I have available.
But really it basically takes more determination and time than I invest to make some progress. My spintop related interest shifted in part to throwing pegtops after my first visit to Marines, so that is part of my lame excuse.


Maybe your new world record inspires and motivates me to continue again with endurance tops.

[Iacopo]

Thank you for re-posting this, Ortwin.
I am re-reading it, there are parts that I didn't even remember.
I will reply here, later.

[Iacopo]

Have you ever tried to spin this top with multiple twirls ?

[ortwin]

Have you ever tried to spin this top with multiple twirls ?

I have a stem that should allow in principle multiple finger twirls. But when I tried I noticed very soon that the technique requires quite some practice and that it can be dangerous for the top. So I gave up on that telling myself that I prefer for my tops the single twirls start .

[Iacopo]

Have you ever tried to spin this top with multiple twirls ?

I have a stem that should allow in principle multiple finger twirls. But when I tried I noticed very soon that the technique requires quite some practice and that it can be dangerous for the top. So I gave up on that telling myself that I prefer for my tops the single twirls start .

I thought that, accelerating gradually the top, would have posed less stress on the spokes.
Also, the higher speed obtained with multiple twirls could make more evident the aerodynamic advantage of your design.
But I understand that you developed it for single twirl spins, and the size of your ring, by itself, seems more suitable for single twirl tops.

[ortwin]

Not directly related to the rest of this topic, but on the other hand it is reminiscent of some things here.
Anyways, recently I bought this endurance top at Kreiselparadies.de.
https://www.kreiselparadies.de/Metal-To ... :5612.html
I saw it is also available at Amazon https://www.amazon.com/Plexity-Labs-UFO ... M77W8?th=1
It is advertised to run for 15 minutes, so far I managed 14 minutes and a few seconds.

An obvious improvement to the design would be to use a material with higher density than the stainless steel used and maybe a smaller diameter ball as tip.

[ta0]

I saw it is also available at Amazon https://www.amazon.com/Plexity-Labs-UFO ... M77W8?th=1

The video on Amazon is hilarious. "A launch to a new dimension . . . we need you to join us in this cosmic adventure . . . (etc)"

It is advertised to run for 15 minutes, so far I managed 14 minutes and a few seconds.

Well, at least that spec is correct. And you didn't even have to use their Astral Axis Spin Base.