16732 rpm ball innards

[AM.]

I'd like to take a look at the internals of the 16732 rpm ball, with good close-ups of tracks, rotor pins and other elements. Available video proves only standard-looking shells and standard-looking counter.

Or in case that particular ball no longer exists for some reason, a 16k+ ball will do (IIRC, there was not a single sub-16k score from Mr. WR during several last sessions).

[Akis]

I'd like to take a look at the internals of the 16732 rpm ball, with good close-ups of tracks, rotor pins and other elements. Available video proves only standard-looking shells and standard-looking counter.

Or in case that particular ball no longer exists for some reason, a 16k+ ball will do (IIRC, there was not a single sub-16k score from Mr. WR during several last sessions).

You may find loads of 16k+ balls over here.

[Scrooge]

AM. It's AKIS were talking about... Show some respect. Sub 16k is not an option for him. All the balls are the same.

[AM.]

Respect comes with proven achievements.

How about some photos of the internals, really?

[Enda]

The proof is widely seen on the scoreboards and in person by a large number of people at the live championships.

Just because you were not at the championships it is wholly unreasonable for you to now come along and demand proof while discounting the independent analysis and feedback provided by others.

Its up to Akis Andy - I think you got your answer above. He won't be taking pictures of the 16k Powerball for you.

Should we hold another championship in the near future you're more than welcome to attend.

Regards

[Adrena1in]

Respect comes with proven achievements.

He proved himself to me, right infront of my face, and on several occasions, even managing 15.5k on a ball that had only been spun for half an hour or so.

[AM.]

Pardon the late reply if you were expecting one, I'm rather busy these days.

He proved himself to me, right infront of my face, and on several occasions, even managing 15.5k on a ball that had only been spun for half an hour or so.

The proof is not just getting the score; or even just checking the frequency without knowing how many fins there are on the rotor. 15.5k on a ball that had been spun for 5 minutes but for some reason has thinner axle or coating or tracks or something else is neither surprizing nor impressive. I got the same score as you on your own ball after all and could probably manage that feat again although I don't have any illusions about my current powerballing form and, more importantly, getting a higher score than my osc. rate allows in case you'd want to send me your 15k ball for a try.

Just because you were not at the championships it is wholly unreasonable for you to now come along and demand proof while discounting the independent analysis and feedback provided by others.

No, not because I was not at the championships. At all.

And since you refer to independent analysis by others, how about I share some of my own here?

Some of this was posted before, and was probably deleted along with my posts when I invited Akis for a spin in Athens back in 2009 (and invited him again during summer of 2010 via RPM Sports with similar outcome).

One thing is sound. Akis's ball simply doesn't sound like mine, and it's not like one camera providing better sound and another one worse; it's like hearing someone you've known for a long time talk in a different voice to you. You can tell it no matter what kind of cell phone is used for communication or room acoustics for recording, and this is exactly the case with his ball. It simply sounds differently (and I have a good ear).

Even if someone is willing to argue that this is a very subjective thing and can't be used as an argument, there is at least one more thing, entirely objective.

I don't know if anyone here looked at anything more than the top speed on the powerballalyzer (or any other tool) graph as I don't recall relevant discussions. Anyway, I did and what I see does not convince me that Akis's videos, among some others, are demos of a real achievment.

First, some basics of rotor dynamics. Not many may be familiar with the notion of moment of inertia; simply put, this is analog of mass in linear motion. The heavier a thing is, the more difficult it is to accelerate or stop it, right? The same applies to rotational motion (many may have had a chance to see what a bullet-proof door is, and what effort it takes to open it, and in case you are not too careful (or too strong), it takes similar effort to stop it from crashing into the wall or dedicated stop!).

Or recall the demos that your physics teacher may have been showing you, like two similar cylinders rolling down the slope when one is much faster than the other, or two rotors suspended on strings wound on their axle and moving up and down, accelerating and decelerating with a different rate. Too bad if you missed those lessons, but try typing in "moment of inertia" in youtube's or Google's video search box and you're likely to find many more.

The reason why one cylinder or suspended rotor is faster than the other similar-looking one is different moments of inertia. If both were allowed to slide down the slope we wouldn't see any difference if they were the same weight, but when friction constrains them from doing so, the situation changes: moment of inertia can no longer be neglected, as one more equation comes into play: T=I.d2f/dt2, analog of well-known F=ma formula. The rate at which cylinder rolls down the slope is determined by its moment of inertia.

Let's now look at the powerball. Its detailed dynamics is not trivial, but laws of physics are universal and apply just as well, although in various combinations. Just as the case with rolling cylinders, friction constrains rotor from sliding into a different position when torque is applied that tries to change the orientation of its axis of rotation (you can check it easily by lubricating the tracks), and it needs to roll, accelerating in full accordance with the basic equation of rotor dynamics.

This takes me to something I spotted a long time ago and mentioned here before: angular acceleration of powerball rotor in Akis's video, e.g. 16732 rpm one, which is close to 3000 rpm/s as you can easily discover with the aid of relevant tools (powerballalyzer will do just fine for this purpose).

3000 rpm/s is approximately 2x higher than the max acceleration I can get out of a standard classic NSD ball. And not for lack of better technique or force (as I discovered, I'm one of not too many people who are able to break the rotor axle), but because the ball is unable to convert external torque into higher acceleration. I can easily drive a ball into slipping if it slips or into switching the tracks if it doesn't (when the rotor happens to be too far behind the hand accelerating it). In any case there is a limit at max acceleration, easy to feel for an experienced person and easy to try to overcome with one of two above-mentioned outcomes.

That's it. The much higher angular acceleration of the rotor may be indicative (but not necessarily is *) of a much lighter rotor (to be precise, having a much lower moment of inertia) used. And unless Akis or RPM Sports agree to hold a transparent test, there's just no reason for thinking people to believe in this and many other videos.

PS enjoy the pics

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* because 2x higher acceleration can also be a result of balls with 2x number of fins to fool powerballalyzer or 2x speedup of a video to create a more realistic illusion (in addition to using the 2nd magnet to fool the counter or 2x thinner rotor pins).

[tburke]

One thing is sound. Akis's ball simply doesn't sound like mine, and it's not like one camera providing better sound and another one worse; it's like hearing someone you've known for a long time talk in a different voice to you. You can tell it no matter what kind of cell phone is used for communication or room acoustics for recording, and this is exactly the case with his ball. It simply sounds differently (and I have a good ear).

I believe it sounds different than your freshly new ball. I get near that sound with a ball that I have used in a lot of strength runs. I suggest you'll try that too. In my opinion that's the key to achieve good scores. I also use it to power up my arms. Usually after a nice two hand 30s run I get the best results (like this newest score of 15k4).

Regards, Tuomas

[Enda]

The much higher angular acceleration of the rotor may be indicative (but not necessarily is *) of a much lighter rotor (to be precise, having a much lower moment of inertia) used. And unless Akis or RPM Sports agree to hold a transparent test, there's just no reason for thinking people to believe in this and many other videos.

How then do you explain this:

Maplin (an independent third party) brought 24 brand new Powerballs in factory-sealed boxes to the event in Telford.

Each competitor got a new Powerball out of the box and spun it in full view of everyone else for a warmup period. Akis then produced 15.5k on one of these balls.

No changed rotors, no differences in the Powerballs.

Andy, this is the last of it. One more post from you on this and you're banned permanently. I'm sick and tired of you and your negative distrustful comments regarding the hard-won achievements of the community.

There is no conspiracy theory, there are no "special" balls. Its a fair competition, and everyone competes honorably. If you can't accept that then its time for you to find a new hobby.

Regards

Enda
--

[LTLFTC]

Lets assume your deluded ravings have some truth for a moment.
The addition of a single fin will convert a 13500 score into a 16875, yet in appearance they will be completely different and patently obvious, also how do you fool the counter.
Twice speed video. So ridiculous, it would be funny to watch though someone please do one.
2nd magnet would turn an 8000 score into a 16000 score again the difference would be so ridiculous it is laughable.
A thinner axel or lighter rotoris the only reasonable argument you have. Lets say they send Akis a special ball with thinner axels or a lighter rotor, as soon as some one else uses it bang goes that theory. And how do you explain his high 15k score on everyones balls, and Jez spinning 15k on a random ball from a shop fresh from a box in Mapplins.


You have spurted a lot of nonsense but the one thing you have said that really struck home for me and explains all your problems in a nut shell is this

Yes, I recall I came across something similar many times in this forum, but always wondered why it is that way. A spinning powerball exerts torque on whatever holds it in a circular manner -- to put it simply; surely the most optimal way to control powerball is to apply torque "in a circular manner" as well, if you get the idea?

That statement while logical is patently false and the reason you fail to score high. As long as you attempt to input energy during the entire spinning of the powerball you will never score well.

The point is, a back-and-forth action shall use only, say, 50% of the time to speed the rotor up, wasting the other half "yielding to powerball" for lack of better wording from me and, as a result, slowdown of the rotor, which is inevitable as a human arm is not a perfectly stiff structure.

That statement you need to get your head around. Watch the good spinners they input the energy at the single optimal point in the cycle then back off until it comes around again to that point. The human body is incapable of spinning the wrist fast enough for a 16k score, it is more than capable of pulsing fast enough for a 16k score. There is very little rotation of the wrist in a good technique but a lot of rigid pulsing. Stop trying to monster the ball listen to it and ride the pulse then you will score well.