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[Bob Gunther]

Hi all. New to the forum.

Been making simple wooden spinning tops, as pictured, for the past 6 months or so.  I'm wanting to increase the durability and quality and I have recently learned that using a bearing ball does just that. So my question is, what is the most reasonable option for the tip? Stainless, ceramic, tungsten carbide or something else altogether?



Thanks,

Bob

[yoyospin]

Bob, installing a separate and more durable tip can be a little tricky. If the tip is even the slightest bit off center, your top may wobble. So drilling a shallow counterbore precisely where you want the tip to be is critical. As for what material to use, there are lots of options...ball bearings, stone cabochons, metal or stone rivets, glass or ceramic beads...pretty much anything with a point or spherical shape. I'm partial to colorful stone rivets like these found on Etsy:

[Bob Gunther]

I'm partial to colorful stone rivets like these found on Etsy

They look awesome. Nice work yoyospin!

I'm up for the challenge of placing the tip correctly and I am actually quite interested in learning how to balance a wobbly top. But first I'll work on the tip. So, it sounds as if there isn't really a single preference to one type of tip. Stainless bearing balls are inexpensive so maybe I will start with those and then the ceramic ones are very durable and I have a source for them as well. But I will be keeping my eye on those stone rivets ... they are a certainly an additional design aspect what with a such wide range of colours!

[the Earl of Whirl]

Stone rivets!  Good idea.  Oh, and a big welcome to Bob Gunther.  I look forward to seeing some more creations!!!

[cecil]

For a tip I would use Stainless or just steal. The only way I know how to turn Carbide is grind or burn.

[Iacopo]

I am actually quite interested in learning how to balance a wobbly top.

Here you can get some useful informations:

[Jeremy McCreary]

Welcome, Bob! I really like the variety of shapes and decorations.

Iacopo started a good discussion of tip materials here. Just bear in mind that his tip wear rates will probably be a lot higher than yours, as his tops are probably a good bit heavier and spin well over 30 minutes in some cases.

I also make finger tops, though in a different medium. Whatever tip material you end up using, I'd recommend paying close attention to the radius of curvature (RC) within the contact patch, as RC can have a big impact on spin-down behavior and some impact on spin time as well.

As you've probably noticed, the very small RCs on the tips visible in your photo favor long, smooth sleeping spins while discouraging travel on hard surfaces. That's often the desired behavior, and the new materials you're considering will make such fine tips much less susceptible to wear and damage.

For more varied behavior, you might also experiment with tips with larger RCs like the ones yoyospin showed, as they tend to favor travel and precession over quiet sleep in place. This is especially true in tops with higher centers of mass. The trade-off: Larger RCs also tend to reduce spin time by increasing tip friction -- especially on magnifying make-up mirrors and other concave surfaces.

[Bob Gunther]

... I'd recommend paying close attention to the radius of curvature (RC) within the contact patch, as RC can have a big impact on spin-down behavior and some impact on spin time as well.

From my limited knowledge and research, I have learned that a 1/4" bearing ball is a good start. As my response to Cecil, I hadn't considered shaping the tip and for now, I think I'd like to start with a round tip.

Great advice in the rest of your response and I have taken notes!

Here you can get some useful informations:

Thanks Iacopo! That's the video I found through Google that brought me to this forum in the first place!

For a tip I would use Stainless or just steal. The only way I know how to turn Carbide is grind or burn.

Interesting ... I hadn't actually considered turning the bearing balls, just using 1/4" ones in the tip.

Stone rivets!  Good idea.  Oh, and a big welcome to Bob Gunther.  I look forward to seeing some more creations!!!

Thanks! I expect I will be quite active here. I find spinning tops fascinating on many levels ... as a toy, as science, as objects of art and beauty ...

[Iacopo]

what is the most reasonable option for the tip? Stainless, ceramic, tungsten carbide or something else altogether?

To me stainless is not very good, it is a bit too soft; it wears out more rapidly than other materials, and, if hitten, it dents more easily, then the top becomes unbalanced. It has higher friction than many other materials.  I like stainless (and its durable and shining polishing) for other uses, but not for making tips.   
Ceramics and carbides work well.  Carbon steels and hss steels work well too.    Ruby and sapphire balls too are used successfully.  Teflon balls are another viable option, they have low friction, but they are soft and need to be replaced from time to time.

[Bob Gunther]

Excuse my over excitement ... I really want to get these bearing balls so that I can get to it and see if I can make better tops with longer spins!

So, if I understand correctly, are the following two descriptions of bearing balls a good start? I'm in Canada and the source is bearingscanada.com

1. - "Loose Carbon Steel Bearing Balls 1/4" inch, quality is G40."
2. - "Ceramic Balls 1/4 inch 6.35mm Si3N4, Grade-5 quality"

Thougts?

[Iacopo]

and see if I can make better tops with longer spins!

Grade 5 balls are very good.  The lower the grade number, the higher the precision of the shape of the surface, which translates in a littler contact point between the ball and the spinning surface, and less tip friction.

If you make wooden tops, and you would like longer spins, a good tip will certainly help.
My best spin with a wooden top, (iroko, 111 grams, hss tip), is 7'45".
In case you want spins quite longer than this, the most important improvement would be to use a metal flywheel instead of a wooden one.  This would make a huge difference.  Tops with a metal flywheel can spin for half an hour or even more.  The trick is to reduce the volume of the top, and consequently the air drag, without reducing its rotational inertia, so, practically, this means a denser material for the flywheel, the denser, the better.
 

[Jeremy McCreary]

Thanks! I expect I will be quite active here. I find spinning tops fascinating on many levels ... as a toy, as science, as objects of art and beauty ...

You're in the right place. The top-makers and top-players here view tops in exactly the same way.

A thought about spin time: My top designs are generally driven by some visual effect or behavior or physical principle I have in mind, and I think I see some of that in your photo as well. And gambling tops aside, I try to get the longest, smoothest spins I can out of all of them, just like everyone else.

My longest-spinning top stays up for almost 5 minutes by hand. That's nothing by Iacopo's standard, but the chase is most of the fun.



But some of my biggest favorites -- especially the really entertaining ones -- spin for less than 20 sec...

[Jeremy McCreary]

I'd love to get a better look at your tops -- especially the one next to the apple in your avatar. Any video?

[Bob Gunther]

I'd love to get a better look at your tops -- especially the one next to the apple in your avatar. Any video?

The top you are referring to in the avatar is no longer with me. A kid was rather mesmerized with it and she is now the new owner. As for a video, well, I've never made a video ... of anything ... ever ... LOL. I will try to make a video of some of my other tops with my wife's phone and see how that turns out.