Wat makes bimetal yoyos superior to plastic-metal yoyos


#1

With the high strength and low density of modern plastics, any weight distribution of a metal or bimetal yoyo can theoretically also be achieved on a plastic body with metal rims. In theory, you can make the bodies of an anglam or draupnir out of plastic, while keeping everything else the same including overall specs, shape and the size of the weight rings themselves.
What factors in reality, either physical or economical, are hindering the improvement of performance in plastic-metal hybrid yoyos?
/topic


(Owen) #2

I assume metal is more reliable and that the distribution of it is more even because it is machined not molded.

Maybe you could do this with delrin though.


#3

Bi-metal yoyos make it so that there can be more rim weight(Which makes the yoyo more solid, smooth, and other stuff) by adding denser materials to the rims of the yoyo.


#4

read my post plz


#5

I assume you meant that producing plastic yoyos to have the same precision as metal ones will also drive up the cost to the same level as a full metal.
You have a point, but many metals are more than twice as expensive as plastic w/metal rings, while most plastics today actually do have achieved a >50% rate of being smooth.


#6

Oh I read it wrong sorry. I did actually read the post, just not that thoroughly.


#7

I like this question. I have always liked plastic-metal hybrids, except for yyj, for one main reason. I can chuck my protostar or rally in my bag or pocket along with keys, pens, etc, and not have to worry about external scratches showing or anything of the sort. plastic outer does not show scratches and dings nearly as much as aluminum. or at least it doesn’t bother me as much. I don’t like the yyj design of something like the DMII where there is metal and plastic on the outside, so I feel it when I throw. feels cheap to me.

on to performance. Theoretically, I see no problem with your logic. as previously stated, plastics are generally molded with the exception of delrin, so there is generally a problem with making them spin smoothly. On the other hand, there are some really solid plastic-metal hybrids out there. What I have always wanted to see is something similar to the body of a protostar, but with weight rings like 2X or 3X the size. I am really curious as to why companies haven’t gone into making the metal weight rings out of big, heavy steel.


(Owen) #8

Maybe you figure out the ratio of the density of aluminium to the density of the steel used in the rims of the various bi-metals and you could transfer that over to plastic yoyos. Maybe you could even use a denser plastic for the rims in stead of metal.


#9

YoYoJam experimented with plastics of different densities - the SpinFaktor HG (“Heavy Gravity”), for example. They’ve also used an array of metals - brass, copper, titanium …

There’s a bunch of issues at play with plastic-metal hybrids. Plastic molds are expensive. There’s a limit to how thin you can go with the plastic before it becomes prone to cracking. Most yoyoers aren’t excited about paying more for a plastic-metal hybrid than metals cost … etc.

I think it’s also important to note that, at least in my humble estimation, we’ve been at a point for a while in the world of yoyoing where the technology is way less a limiting factor than are the users of the technology, and I suspect that someone like Takeshi could have won worlds 2014 with any of the yoyos he’s won worlds with in previous years, such as the Lyn Fury (plastic) he used to win in 2008 or the Destiny (plastic-metal hybrid) he used to win in 2011.


#10

I won’t get into which is better, or if you can make them the same… at least for the moment… but there is a factor you’re skipping over.

A wall of plastic that weighs the same as a wall of metal, is going to necessarily be quite a lot thicker… both because it is lower density, and because it has to be for strength. This is going to change the overall numbers in a real way… whereas you can be pretty thin with a metal wall and put the weight -exactly- where you want it, not just in the general area.

Kyle


#11

Very simple, plastic can´t substitute metal even if it can be of similar density, if the technology could make plastic with the same qualities of metal and cheaper, why there is no building structure made by plastic?
You can make a plastic as dense as metal, but it will be or too hard that will break so easy or it will be too soft that will bend. There is no conspiracy theory, I´m sure the designers have tried to emulate it many times so far.
I can quite safely say that currently it is not possible due to one of this two reasons: plastic can´t emulate metal close enough or if it does, is just too expensive.


#12

Well the Triad is pretty close to a plastic Draupnir, I’ve even heard it said that it plays similar.

http://thumbnail.image.rakuten.co.jp/@0_mall/yo-yo/cabinet/44re/img61751689.jpghttp://cs616718.vk.me/v616718434/b2b4/2bnRi4oPzkE.jpg

Commenting on the “economic” aspect, and to expand on what Jrodriguez mentioned:

I think that the reason why plastic/metal hybrid’s aren’t seen often (nor having envelopes of design pushed) is because of the added expense of manufacture. You get a combination of:

  1. The cost of having a mould made for a plastic throw.
  2. The cost of machining the metal parts.
  3. The cost (in manpower) of assembly.

Now this isn’t too much of a deterrant for the large companies like YYF, Duncan, Yomega etc, but for smaller yoyo companies (which lets face it, most are) it’s a lot of extra time and money over the price and comparative ease of manufacturing a standard metal throw. Heck, the whole Yeti thing almost put CLYW out of business due to the cost of getting the moulds made and the hassle of assembly.

It isn’t like a metal yoyo that you can knock out some whacky envelope-pushing prototypes one at a time and see what happens, each plastic yoyo requires an entirely new mould to make, so there’s very little room for trying out-of-the-box ideas unless you know they are guaranteed to work. With so much money at stake, it’s unsurprising that many companies aren’t as willing to push the boat out.

^Very much this. “Performance” is such a subjective term. Here we have John Ando doing a solid 1 minute ‘one-throw’ with a Yoyofactory Richochet (~$200)

Whilst here we have Malcolm Chiu getting a 1 minute ‘one-throw’ with a Protostar ($35.00):

So whilst perhaps yes, hybrids throws as a whole don’t tend to ‘perform’ quite as well as metal throws (I’m sure if I gave Malcolm a 7075 Genesis he’d far exceed 1 minute), the difference is not enough to display a serious detriment to one’s throwing.

In fact the level of play we’re getting out of plastic/hybrid throws at the moment is fantastic, between:

Onedrop Rally
YYF Protostar
YYF Northstar
sOMEThING Addiction
Yoyorecreation Triad

The performance and quality of hybrid yoyos is the highest it’s ever been. :slight_smile:


#13

The rings of a triad weigh more than those of a draupnir.
The density of aluminum is about ~2 times of that of common plastics (PC, POM, etc), and when the metal rings always weigh as much as half the entire yoyo, the inward shift in weight distribution caused by a 1-2mm thicker plastic body compared to an aluminum one I assume is negligible.


#14

while in theory they should perform better because they can potentially have more rim weight. Todays plastic is strong enough to not have to be 2x thicker than aluminum.

Hows the cost of producing machined delrin yoyos?


(Bína) #15

[quote=“kadabrium,post:14,topic:69949”]
About same as metal, sometimes even more expensive, since it’s more hassle for manufacturer.


#16

I’m not sure what you’re trying to say… are you saying that the triad and draupnir are the same? because you kinda say the opposite… if the triad rings are heavier, and the body is lighter, it’s a much higher rim weighted yo-yo and is therefor totally different.

I pretty specifically stated I wasn’t saying one setup was better than another, just that how you can distribute weight in a plastic body is different than how you do it with metal… which you just confirmed… so I’m kinda confused as to what your point was?

Kyle