??s for spinny top turners

[Warren White]

OK. I was about 7 for 7 in the top business (meaning that they spun quite well). I gave them to my grandsons and they liked them. My HS Senior granddaughter wanted one, so I went back to the shop to make one more 'creative' for her by gluing a piece of metal at an angle on the square blank I turned. Looked great, but it wouldn't spin worth a darn.

Next, I decided to laminate thin pieces of maple/walnut/maple in the walnut blank I turned. After discovering that the glue was not infallible to the stresses of turning (little chips here and there) and in trying to fix it, the score of those two became blank=2; me I=0 (if you get my drift).

Second try on another laminated blank and it spins, although poorly. I suspect that in the process of turning past the little chip-outs I turned it too small in diameter. Score now: me=.5 and the blanks=2.5 (again, if you get my drift).

So, questions for the experts: Is there a minimum diameter of the tops? It seems to my physics-starved brain that too small won't sustain the spin... Is there a proper ratio between the height of base of the top and the spin handle? Is there something that you can do to enhance the balance of the top (like undercut the top of the base to increase the angular momentum (my high school physics teacher would be happy that I even remember that term). Lastly, is there a preferred shape for the pointy end?

HELP! I can't let something this simple drive me nuts!!!!

 

[BRobbins629]

Although I'm still a little new at this, I have found a few insights. There's not a lot of good design info on the internet and believe me I've looked. As for the point, most of the long spinners I have seen use ceramic balls. I found some 4mm ones on eBay reasonably priced. The pointy ones apparently either dig into what they are spinning on or get dull quickly. The ceramic ones seem to work quite well. Balance is critical so a homogenous piece works best. Theory says more weight on the outside will spin longest but may inhibit the initial speed when twisting. I'm still trying to figure out the best size. I have two similar ones, one being about one inch in diameter and one being 1.8". The small one spins longer which fooled me. Friction also plays a role. My longest spinner increased from 4 minute 20seconds to a little over 5 minutes just by polishing. Still a lot to learn. Have read about ones that spin almost 20 minutes and many in the 10 minute range. Also helps to have a spin plate. I currently use a 4" concave makeup mirror but plan to make a nicer one. Post some pictures. Would love to see what you design.

 

[jttheclockman]

I can not help with the math and all that but can tell you I have seen tops of many different sizes and shapes. I can tell you balance is key. In other words the handle needs to be dead center and the weight of the top on all sides must be equal. The handle I found out can not be too tall but have no measurements. I just know when I made these I got cute with all kinds of shapes for handles and found them too tall so I gradually cut down till I found what works or the type I make. I had shown this recently but here is the type I make. being I am a scroller I cut different designs and then layer them. Turn them on the lathe and find dead center and drill for my handle as I make those separate. I also make the nib which just comes to a point sort of (has a rounded point)

There maybe some info in this to help with math

SPINNING TOPS

 

[magpens]

From a physics point of view, you want the spinning disc to have as high a moment of inertia as possible. That means a concentration of mass (ie weight) towards the outside edge of the disc. And, yes, that is harder to machine

 

[Warren White]

Bruce,

I found them on eBay (thanks for the suggestion). That sounds very interesting. How do you embed them in the top?

 

[Warren White]

John

Thanks for the suggestions. I have seen your tops on the forum and you are quite the artist. Your scroll work is excellent.

I will keep experimenting; I appreciate the observations offered by all!

 

[Dalecamino]

I made these a couple of years ago for stocking stuffers. They worked very well.

The ones that are dished out, and points slightly rounded seemed to spin the longest.

 

[BRobbins629]

I found them on eBay (thanks for the suggestion). That sounds very interesting. How do you embed them in the top?

I usually drill on the lathe with a centering bit and slowly drill until the tapered part will allow the ball to seat about 1/2 way. Then a drop of medium CA.

 

[JimB]

All good advice above. Segmenting is going to cause balance issues and will dramatically impact spinning, even prevent it from spinning. The tops I make are from a single piece of wood. Keep the center of gravity low. In other words, don't make the base of the top too tall.

 

[Warren White]

I ordered some Ceramic balls today. I will let you know how it turns out.

Thanks for the suggestion.

 

[Warren White]

I received the ceramic balls from eBay....

...and I have turned 7 tops. Lessons learned?

1. Following Bruce's advice (which was EXCELLENT), I was able to drill and attach the balls quite easily. The only down side was finding one of them that I dropped while I was fitting it. Any idea how far they can roll?

2. While the use of the ceramic balls is a very positive step, they don't make up for mistakes in the physics of the design. I made one that looks like a top (triangular from the top right down to the base) and it won't spin worth a darn. Mal's physics explanation was EXCELLENT as well! My last one was turned according to his suggestion and it did quite well.

3. I made three using a dowel for the center piece and again, physics rules. They all spin, one better than the others.

4. John's link to the physics of tops was very interesting, and I appreciated the reference.

5. Dale's examples, words and pictures certainly reinforce the physics. They will be my model from now on. The 'dished out' concept seems to be a major key. And, yes that does make them harder to turn. I don't have the skill do do them in 10 to 15 minutes quite yet. Working on it, however.

My granddaughter (and others) will benefit from your help on what may seem like a silly question. My thanks to all!

 

[BRobbins629]

Pictures and spin times?

 

[Warren White]

Well.....

.....the pictures aren't all that good, but here are two that spin the "best", and they don't measure up against others that I have heard about.

Spin times are a bit over 1 1/2 minutes when spun on my Corian counter top. A larger diameter would (I think) increase the time. These have a diameter of 1 1/2 inches.

Hmmmm, the spin time is about the same as the diameter. What if I made the diameter 5 inches? (Just kidding....)

 

[randywa]

If anyone has a foolproof method for making two functional tippee tops in a row, this fool is interested. I think my average is up to about 1 out of 5 without a lot of fussing and cussing. I'm starting to think it's all in the lucky socks.

 

[Warren White]

Hi Randy (aka Kindred Spirit)

I really liked your post, and I share your frustration. I admire those who can do these in 10 or 15 minutes, and who can get them to spin for five or ten minutes. I can't do either, but I love to turn them anyway. Several of mine have turned into conversation pieces and the conversation goes "What are these?" "Tops." "Why don't they spin?" "I don't know, but this one does."

I just turned another. It is made of Osage Orange. I didn't put any finish on it. I went back to putting a 3/8" dowel through the 2" square blank that was about 3/8" thick. I left the dowel long on both ends of the blank so I could turn the face of first one side and then switch the top end for end so I could turn the face of the other side. I turned a concave shape on both sides of the Osage Orange so the mass would be concentrated near the outside of the top. (I hope that makes sense.)

This top, strangely enough spins for 2 minutes. 2 inch square = 2 minutes spin.

The picture was taken while it was spinning. This top also has the ceramic ball on the bottom. I am about out of them so I will need to order more. I don't know why this picture (which is up and down on my computer) wants to be sideways in this post. My apologies.

Hang in there Randy! When we get one that works, it makes up for a lot of frustration.

 

[Dalecamino]

They look good Warren!