Stability?


#1

This is kind of an amateur question to ask, but I’m just gonna ask anyways. What is it that will give a yo yo good stability? Is it rim weight, central weight, centralized string (kk/ct/grooved bearing)? Or is it all good technique? I ask because I tend to tilt quite a bit. I wrote it off as sloppy technique initially, but it can’t just be me. Can it? Reply and tell me.


#2

What yoyo are you using the it tilts and yes, 90% change it is just you.


#3

yoyos with a small inside face tend to be more stable, and yes it can be just you.


#4

I’m using a Dv888. Dang. I was afraid I’d get that answer. But I can fix that!


#5

Yes my dv888 is very stable for me, so just practice.


#6

There are only a few (only one that I know) parts of the yoyo that causes tilt. Everyone who posts on this thread will probably say it’s your throw and yes it just may be. Is your Dv888 standard or like non-modified? If your Dv888 is standard, it should be your throw, if it’s modified, explain.


#7

make sure your throws are straight and the yoyo doesnt come down slightly tilting to one side…


#8

My Dv888 isn’t modified any. And I’ll end up tilting on straight throws. I think that the tilt might just be caused by sloppy play. No big deal. But what I really want to know is what about a yo yo in general will give it good stability? I want to know as a personal reference for future purchases.


#9

Well, what do you mean by stability Do you mean vibe? Here:
In super rare conditions, there may be un-even weight on each side of the yoyo
Normally, vibe comes from molding plastic into metal or aluminum rims. In other words this is called a bi-metal yoyo. Vibe comes in them more than full metal.
A cracking or breaking bearing seat may cause tiny vibe.
Any large damage to the yoyo will cause vibe. (What I mean by large damage is like a 2 thumb sized cracks)
A cracked or breaking spacer may also cause vibe (Not Always)


#10

I don’t mean vibe. I just want to know what about a yo yo’s physical attributes causes it to maintain good stable spin without being as susceptible to tilting in the middle of tricks. Is it more rim weight or central weight? Or is it something else entirely? Technique aside.


#11

Ohh, sorry for my mis-understood posts. As stable spin does need rim weight. But there are 2 things to clarify:
Spin: Spin should come from momentum which is caused by an outer edge of heavy matter, therefore, in this case would be bi-metals.
Stable: Stableness sometimes come from the “guts” or the insides of the yoyo. There is a great example, the YYJ SSA (YoYoJam Solid Spin Axle). The whole place where the axle goes in is metal rather than just a brass threaded “hole” for the axle molded around the plastic. This does not affect vibe, but a solid spin is obtained from it.
Also SFX has precisley precisioned metal rings in the center of the body but I don’t know why it isn’t on the rim. Maybe someone else will tell you.

                                                                                   Have Fun! :D

#12

Holy crap, are you serious? What kind of pseudo-science garbage are you spouting? “bi-metals” cause more vibe than other materials? Really? Would you please try to give factual information? Please, for the love of god, actually know what you’re talking about before you open your mouth. Your posts are like a magic 8 ball of misinformation.

To the original poster: all modern yo-yo’s are engineered and machined for maximum stability. Of course, depending on design, some will be slightly more or less stable than others. But, if you practice your throw and focus on making it as straight as possible, the tilt potential will be barely noticeable. If it’s that big of an issue for you, stay away from extra tall or extra wide yo-yo’s. Choose a throw that’s pretty balanced as far as height/width goes. They’re much more forgiving.


#13

Stability, in a yoyo, is an extremely complex thing to both comprehend and design.

Simple vector physics tells us that the Moment of Inertia is the tendency of an object to resist rotation. Or, if rotating - to resist a change in angular momentum. Newton’s Second law tells us essentially, that an object that is rotating, will continue to do so unless acted upon by an outside force.

Here is where yo-yos get really interesting. A yoyo is essentially two shapes that are classically described in physics. It is a disc with a protruding ring that rotates around a fixed axis.

The Moment of a disc: I = 1/2 * M * R^2
The Moment of a ring: I = M * R^2

Notice the difference between the moments of the ring and the disc? The ring will tend to stay rotating twice as much as the disc. This is where weight distribution and placement become very important in the design of the yoyo.

I have oversimplified - but suffice it to say that the placement of the ring weight is important to suppress another physical phenomenon called precession. Place the weight all on the rim - and the yoyo will want to rotate around the string as it spins. That explains the weight ring placement on the YYJ Phenom - and why it is the most stable yoyo I know of.

Now add in the curves and connected weight distribution - and you have something that is more art than physics. Clear now?


(Q) #14

And by oversimplified, you mean?


#15

…Well, since you ask…
This is really a multivariate calculus problem. Viewing the yoyo as a disc, joined to a cylinder is oversimplifying the design of many yo-yos. To properly determine the moment of the yoyo would require modeling the curve of the yoyo shape and then using integral calculus to sum the weight distributions over these curves.

The thing I wonder - and maybe a real yoyo designer could answer this - is whether there are reliable computer modeling (CAD) programs to model the yoyo’s behavior in software? It would seem to me that if the yoyo is being designed using CAD programs, then the curves are all parameterized and should be able to be modeled before an actual prototype is produced. Is this possible?


(Q) #16

Oh. Now I get it.


#17

Awesome. YoyoGeezer has given the answer I was looking for. Also ShaunC’s reply was helpful. Now, I’m going to try and summarize and see if I understand: The key to a stable design is balance. There shouldn’t be too much weight in one area. If there is too much rim weight, it will be more susceptible to tilting. If there isn’t enough rim weight, the spin times will suffer. So a great yo yo design would be one that has most of its weight distributed on the rim and in the center, and minimal weight in between. So maybe an H-shape, or maybe substitute that with a pronounced IRG, with a central post of some kind would be the best choice, especially if it’s height and width measurements are nearly equal. Is this correct?


#18

You have the basic idea. Too much weight can be bad just as bad as too little - as I was told by a real yoyo designer. Too much weight on the rims causes PRECESSION (look up on wikepedia) - not tilting. Tilting is usually a bad throw.

As for weight distribution, you are correct. There needs to be some on the rims as well as around the axle/midway. Look at a CLYW design. They place a lip on the interior about midway, and then a lip on the rim for spin time.

As you are probably guessing, there is part physics, part trial/error and part intuition. That intuition part is what I suspect separates the CLYW/OneDrop’s of the world from the rest.


#19

You have the basic idea. Too much weight can be just as bad as too little - as I was told by a real yoyo designer. Too much weight on the rims causes PRECESSION (look up on wikepedia) - not tilting. Tilting is usually a bad throw.

As for weight distribution, you are correct. There needs to be some on the rims as well as around the axle/midway. Look at a CLYW design. They place a lip on the interior about midway, and then a lip on the rim for spin time.

As you are probably guessing, there is part physics, part trial/error and part intuition. That intuition part is what I suspect separates the CLYW/OneDrop’s of the world from the rest.


#20

Good question. We keep reading about all of these efforts put into the design phase, but it almost sounds like trial and error sometimes (which can be a valid method given enough time and resources). I would be very curious to learn from a discussion on exactly what you’re proposing.