I agree that it is a CYA statement to a degree but at the same time you have zealots like Geezer who trump up the superiority of Japanese throws yet we don’t see this warning for any other companies. If 7075 is as tough as he thinks then the warning would not be needed. Truth be told I would bet the warning is in place because YYR didn’t properly account for the ano layer build up on the posts causing overly tight seats.
Studio said it best. It allows for fine tuning weight distribution. What Geezer has never been able to accept it that a great designer can compensate for the differences and make one hell of a YoYo no matter what alloy is put in front of them. Something I am sure most of us rational people can agree on. A brilliant mind trumps the materials used any day of the week and twice on Sunday.
*Any typos in this post are the result of being typed on an iPhone by some with large hands.
Here’s my view on 7075 aluminum. It is certainly different than 6061, yet not inherently BETTER. True, 7075 can have thinner walls than 6061, etc., but just because it’s 7075 doesn’t mean it will play better. You can use all the strength properties of 7075 that you want, but if it’s a poor design, the type of aluminum used won’t make a huge difference in how the yoyo plays. And just because someone makes a 7075 yoyo means they used its special strength properties. There are always trade offs too, with 7075 in the area of anodization.
Also, a well designed yoyo will be a well designed yoyo, regardless of it’s material. Certain issues need to be addressed in order to do certain things with certain materials though. You can’t just take a good metal design and say, just run the CNC on Delrin, it just won’t work out well. RecRev re-designs their delrin versions, I guess starting with the metal version for shape, but then having to leave material in certain areas to get the weight where and how it needs to be.
I personally like how the GSquared AL7’s perform over their regular counterparts. I just like the additional weight, it feels better to me.
The Dreadnougt I have, at 68 grams, just feels kinda, well, not all there. It plays amazing, but it just feels like it lacks the weight it SHOULD have for it’s size. Amazing design, still smooth and stable.
I love 7075 just because of how shiny it usually is, I’m a sucker for shiny throws. However play wise, I much prefer my 6061 Supernova lite to my 7075 Supernova.
Whilst the same design in 6061 and 7075 won’t display any noticable difference in performance (spin, stability), it may do in play due to the weight difference.
The standard Genesis is 68.7g. Some rough maths shows that the same Genesis in 7075 would weigh 71g, which is a noticable weight difference and would potentially change the feel of play… although in the end that’s all in the eye (or hands) of the beholder.
Durability wise:
As you can see, 7075 is stronger/harder, but less malleable? I don’t claim to know anything about metallurgy here, I’m just googling this. Either way the capacities of it’s strength aren’t anything that would be noticed in the realm of yoyoing, unless you’re using it your new throw to hammer in nails.
Long story short and to re-iterate what people have already said, the advantages to 7075 mostly come in the design and machining of a new throw. When YYF made the Doomsday Genesis, they used the properties of 7075 to remove center weight and alter the weight distribution, producing a sensational throw that was actually lighter than the original. This is what 7075 allows you to do and this is why so many Japanese manafacturers love it. More precise machining, higher tolerances and greater possibilites with weight distribution. =)
No alloy is better than another objectively. They have different characteristics and those characteristics can be applied in design. In design, material is chosen based on the characteristics you want. Context matters.
In terms of the actual difference between the two alloys, 7075 is more dense than 6061. It is also harder and more expensive (considerably more expensive - thus the higher price of the yoyos). Those are the main differences that are relevant to yoyo making.
6061 is used in aerospace - it is an amazing material so I don’t think calling it “cheap” is accurate. Yes it costs less, but it is not “cheap” in the sense of being low quality or value.
Someone also stated that 7075 allows for more precision and this is just simply not true. Material can matter in terms of precision, but it doesn’t in this case.
This question about the difference is extremely complicated and nuanced and there is no single answer. It depends on tons of variables including subjective taste, design, manufacturing quality, etc.
We are enjoying making yoyos out of both materials and taking advantage of the characteristics of each. We are fortunate enough to be able to have these options! Aluminum is incredible stuff.
I like how I completely crashed my Triton on my 7075 Cascade and my Triton got a gnarly ding and my Cascade took it like a man and is still in mint condition.
7075 allows you to make more radical designs, and you can place more weight exactely where you want it. Heavily rim-weighted yoyos benefit from this, as you can thin down the thickness of the walls between the hub and the rim-area, and focus all the weight at the rim. With more centerweighted-designs, this won’t be such a big deal, really, as you’d want more of the weight in the center and walls anyways.
And i’m pretty sure that i read somewhere that YYR couldn’t make many of their designs with 6061, as the thin hub area (like on the Sleipnir) would simply be to weak with “regular” 6061.
Perhaps you could make the walls thinner because it is stronger but we (and others) already make the walls really thin in 6061. There just isn’t room to go much thinner that would make much difference.
This notion that the more weight on the rims the better is not an absolute either. Too much axial rim weight causes pulse vibe. Designing good yoyos is much more nuanced than generally believed. Physics often gets in the way
It’s hard to say actually. Because of the weight difference between the materials, the weight distributions end up being different. The science part is getting the specs to match what is desired and solving engineering problems (this is stuff is subjective). How a yoyo plays is much more objective and this is the art side of it.
It’s not really an advantage, it’s just different.
Probably the best advantage you had with the designing of the Valor was having Vilmos in the shop. This allowed for rapid prototyping and quick changes to the CAD since you could all sit in front of the computer. I would imagine designing a signature yoyo with someone who is a continent away has its own set of challenges.
Absolutely! It was so much faster and better having him here for it. We had already spent months working on the design before he arrived but that was maybe 10% of the work.
Correction below:
The science part is getting the specs to match what is desired and solving engineering problems (this is stuff is objective). How a yoyo plays is much more subjective and this is the art side of it.
There are no opinions when it comes to objective, while subjective is purely personal and opinionated, hence the art side…right brain verses left brain!
Density is not directly related to durability. There are denser metals than aluminium that are less durable.
By making a thinner wall with a higher density material, you can end up with more weight than a not-so-thin wall on a lower density material, it all depends on the width and the materials being used.
In the case of Un-heat-treated 6061 and 7075, 7075 is around 2x stronger than 6061, and is only about 4% denser.
Density is only one comparator. If you want to compare durability and strength of different alloys, I suggest you start comparing each of the materials’ hardness, yield and tensile strength, as well as Modulus of Elasticity (Young’s Modulus). The materials’ comparative behavior becomes quite obvious with a little material science background and the aforementioned information in hand…
And this is why we love db over on the One Drop forums, the man is just a wealth of scientific knowledge especially when it comes to the materials used.
And since he is in here, hey db is there another metal that you would like to see used in yoyo making and if so what unique properties would it bring to the table? (Try to keep it legit, no depleted uranium yoyos. LOL)
Yeah I think a couple of posts on this page have eluded to a key point. If one designs a throw out of 6061, it is designed for optimal performance with that specific weight. If one switches this to 7075 then clearly you have changed the weight because the alloy density is different but clearly you cannot change the density over the distribution of the throw so you have one of two choices - the 6061 or the 7075. Perhaps, and just perhaps, 7075 allows a greater range of designs, but you still cannot change the density and so one shape only has one weight distribution - one cannot create un-physical designs. This is why bi-metals give such a wide variety of play, because one can actually use different metals to change the weight:volume ratio over the range of the yoyo, at specific and precise places within the yoyo. Again this introduces a whole new set of problems, including ensuring precise joining of the bi-metal designs and so on, but does give more scope for radical designs with very specific weight placement. However, I reiterate the first point, if a throw is designed for a weight based on 6061 then it will play like it was designed to with 6061 only. If changing the alloy to 7075, with the same shape, plays better in some people’s opinions then that’s great, but it’s not how it was designed. I, and I suspect many people, tend to enjoy 7075 revamped versions of 6061 throws because of the extra overall weight and change in feel. I will go out of my way to purchase 7075 version because of this, and because I tend to like they feel/play. Again I’m sure nuances and personal experiences play into these decisions but I find it for me to be generally true but there is no reason it should be true for all.
That said, I will throw out that I’m surprised there hasn’t been more use of sealants to fill gaps in aluminum to alter weight. It’s a bit random, and probably not feasible but I would have thought something like Torr-Seal could do the job (some kind of adhesive that binds very well with aluminum).
Something else that has never been answered when I ask this, and I do so again in the hope that someone can give me a prompt or two, is why 7075 is chosen? This alloy is described as having a middling corrosion resistant as far as alloys go, and my guess is that this property alone makes it harder to ano than 6061 (I believe it’s the additional zinc content). Ironically the wiki page says that it is an expensive alloy. There are so many different alloys: why not for example 7068 which has a higher density and would therefore provide a greater change in weight compared to 7075, or 2011 which is denser than 7075 but easier to machine (I have been told by a machinist) for a similar cost?
EDIT - to filipe: I’m sorry you are absolutely correct - I’ve clearly developed a niche problem where I’ve just started writing distribution anywhere. Distribution.
