Wasn’t sure where to post this, so I hope this is an appropriate sub-forum. Mods, feel free to move it if need be.
I’ve been thinking about weight rings more often since the release of the Anglam. I know that particular yoyo features titanium weight rings. My question is: could another material (like brass) be used in place of the titanium resulting in similar play and cheaper price?
Feel free to share any and all thoughts!
Quite probably. I’ve always been of the opinion that people use exotic materials in yoyos primarily for the “sex appeal” or “how cool am I” factor.
Brass would be pretty pointless in a full sized yoyo. Throw it in a mini, and you got a good combo.
More rare metals such as Magnesium and Titanium, that are stronger strength-weight can be used to place weight in exact desired locations without having to place worry about your walls adding too much weight.
Titanium is incredibley dense, durable, and expensive. The desity aids in designs like the Anglam, where it gives it massive rim weight. On designs like the Sovereign, Ti Walker, and Oxy Tis its durability allows incredibley thin walls, much thinner than possible with aluminum. This allows heavily rim weighted designs with perfected physics. These properties aren’t present in brass. Does this justify the increase in price? It depends how much exposable income you have. 
Titanium isn’t that dense. It just happens to be more dense than aluminum. It is, however, very durable and expensive… which is exactly why I made this thread. I find it interesting that the company chose to use a titanium weight ring. Why would you chose to use a very strong metal in a location which is nigh impossible to damage?
The only things I know about brass are: it is dense (more so than aluminum or titanium), it is not as ‘strong’ as titanium, and it is not near as expensive as titanium. That’s about it…
This is exactly what I have been thinking, particularly in the case of the Anglam. I’ve always assumed that they probably could have made the Anglam using a brass ring (or some other metal which is more dense than the aluminum in the rest of the yoyo). Maybe they wanted to give the yoyo the ‘sex appeal’ by adding the titanium? Or maybe it isn’t possible to make a brass (or otherwise) ring that would fit the size and mass specifications?
I couldn’t tell you why. In fact, I don’t really care why they chose to use titanium. I would just like to find out if it may have been possible to use an alternate material to make the weight ring.
Why would brass be pointless? It could give an increased amount of mass to a desired location. I’m talking about just the weight ring being brass, not the entire yoyo.
Strength to weight ratio is not very important in this discussion. I’ve always thought that the strength of a weight ring would be irrelevant… simply based on it’s location. Then again, maybe that ratio becomes important when you try to machine a small weight ring out of a ‘softer’ metal. That I don’t know.
Ti = 4.43 g/cc
Brass = ~8.4 g/cc
When combining with Aluminum body, the density of the Titanium is less than the Brass, so there is less weight consumed by the ring. This yields more possibilities for ring/vs body engineering. Additionally, the weight of the brass may overwhelm the weight of the Aluminum because of the sheer weight/density of the brass being 3X that of AL… This would make for a yoyo with mass mostly concentrated on the rings. By using Titanium, the material density differences are less. This makes a more even weight distribution and a speedy yoyo.
Conceptually, a rotating ring has twice the rotational momentum as that of a disc. You can see that by combining a dense ring with a less dense disc will yield a more stable whole than the sum of the parts. This is the principle behind the Anglam. If the ring is too dense relative to the rest of the yoyo, however, the effects become gyroscopic and undesirable. I have an old English yoyo that is wood, with steel rims on the outside. The difference between the density of steel vs. the denssity of wood creates a powerful-spinning yoyo that will break your knuckles if you are not careful.
Just to briefly chime in with my new found fave, the Stealth Ogre has brass around an Ali frame. Now I’m not going to delve into the physics, but simply say play it and tell me if it makes a difference - I would say for sure it does. I haven’t played an Anglam, but this is pretty good in its own right. But YoYoGeezer is definitely right, if you bind to vigorously then you’d better make sure to cushion the return!
And I don’t mean to hijack the thread too much but the same could be said for choosing a type of Aluminum. People rave about 7075 - I often like some added weight, but I believe this is doped to make it corrosion resistant, or at least so says my favorite Aluminum retailer, so why choose that when it must presumably be harder to ano simply because of the very doping you’ve chosen. There are plenty of other aluminum ‘blends’. YoYoGeezer I suspect has more insight into this than I, but it’s always seemed an odd choice in itself, and one maybe geared to the exotic?
This is assuming that the brass ring is the same size as the titanium ring.
I am assuming you can make a brass ring which has the same mass as the titanium ring that is found in the Anglam. If possible, I would think said yoyo should play similarly to the Anglam.
I have an Eli Dert. It features tungsten weight rings. I don’t know what you mean by ‘undesireable gyroscopic effects,’ but I do know that the Eli plays like a champ.
Very interesting! I haven’t had the chance to play a Stealth Ogre (or, frankly, any yoyo with brass anywhere near the rim).
Not hijacking at all (imo). I totally agree with this. I don’t think that one ‘blend’ of aluminum is any better than the other… different strokes for different folks I guess. It seems like yoyos which are 7075 tend to be roughly 20% higher in retail price than their 6061 counterparts. I’m not sure how much of that cost is intrinsic. I’m also not sure that they are really worth 20% more (to me).
Don’t get me wrong, I’m not an expert in physics or materials science… I’m just curious about all this!
The way I read all of this is that if you are a competent designer you will be careful to not concentrate too much mass on the rims of the yo-yo. The density of the weight ring has more to do with ‘packaging’ (read as ‘volume’ if you feel more inclined) than it does with the actual mass of the final ring.
As a designer, I may know that I want to concentrate twenty grams (10 grams per half) of mass on the rims of my yo-yo. That means that the volume for each ring in my final weight ring design is going to be 2.22cm if I use titanium, 1.19cm if I use brass, 3.70cm if I use 6061 aluminum, and 3.56cm if I use 7075 aluminum.
Yes, in some cases it will matter, and this highly depends on how extreme of a design you are trying to make. However, in most cases it can easily be designed around. In which case it all comes down to:
I don’t think I have studied that before ;).
I wonder if they made a yoyo out of tungstenn…
Which might acually work for ultra mini yoyos.
All of these comments are relevant. My post was in no way implying that Brass or any other material was inferior to Titanium. I was only trying to give a reason why a designer might choose Titanium over another metal that was not sex-appeal. The Stealth Ogre by Sturm Panzer uses Brass rings and 7075 Aluminum to achieve amazing spin-time and stability. So clearly the choice of materials is up to the designer and the needs of the design. Sex does sell, however 
YoyoJoker’s “New Double Joker” uses what I believe is 6061 Aluminum and Delrin to achieve amazing results with multi-density design. Their results are achieved in multiple dimensions. Not only through multiple-desnsity; but also through radial rings. This essentially elongates the axle cylinder to provide a more stable yoyo with less mass than would be expected with a mono-desnsity design. My Double Joker weighs 66g - but has the stability of a 68g yoyo like the Gleipnir while still maintaining the speed and agility of the lighter weight and aluminum density.
As for the 7075 questions - I know way too much about Aluminum alloys. 7075 is ~30% more expensive than 6061 due to its composition. It is aluminum doped with Silicon and other metals. It is significantly harder than 6061 which makes it more suitable for high-stress applications such as Aircraft frames and gears. 6061, because of its opposite properties of malleability (it bends and stretches) and low-density; is more suitable for the skin of an aircraft. This is why they are both referred to as “aircraft” grade.