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Author Topic: dont put a bearing in it!!!!!!!!  (Read 3974 times)

Jack

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dont put a bearing in it!!!!!!!!
« on: May 17, 2016, 04:05:05 PM »

im 90 percent sure ive fractured my finger here @-@
so i tried puting a bearing from a yyf whip into the short circuit and it fit great......everything was great.........untill i threw it @-@
it changes its freaking axis mid boomerang!??!?! what is this nonsense?!?!?? violence!!!! almost broke my tv!!!!! meh!!!!!!!
behold.....

https://youtu.be/pthrIqvPWFs

https://youtu.be/JgaIPJDx7NM

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lincolnrick

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Re: dont put a bearing in it!!!!!!!!
« Reply #1 on: May 17, 2016, 04:20:20 PM »

Wow. I thought the fixed metal tip put a bit of wobble on the short circuit but at least I could boomerang it. That looks awful. At least the tv's okay?  ???
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Jack

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Re: dont put a bearing in it!!!!!!!!
« Reply #2 on: May 17, 2016, 04:36:20 PM »

Wow. I thought the fixed metal tip put a bit of wobble on the short circuit but at least I could boomerang it. That looks awful. At least the tv's okay?  ???

yes...thank god the tv is ok  ;D
damn thing drew blood and my finger is still aching to the bone  :o there shouldnt have been any problem, puting a bearing in seams to make it into a tippie top lol  ;D the wierd thing is is that as you can see in the vid the top is coming back normally tip down and then suddenly changes axis midway back to me  :o

my finger:

http://i1365.photobucket.com/albums/r754/jack1861-1865/Mobile%20Uploads/image_zpsx5gkdlzt.jpg
« Last Edit: September 22, 2017, 11:47:52 PM by ta0 »
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Hroch

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Re: dont put a bearing in it!!!!!!!!
« Reply #3 on: May 17, 2016, 04:52:47 PM »

That's the reason why metal tips are not compatible with Short Circuit. It's just vibrating too much. Ben said he didn't know why.
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studio42

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Re: dont put a bearing in it!!!!!!!!
« Reply #4 on: May 17, 2016, 04:53:53 PM »

What tip are you using? It can't be the bearing itself, but maybe there's too much weight at the tip area now?

Good to know a C-sized bearing will fit in there. I'm currently not inclined to swap tips on any of my Energia tops at the moment.
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Jack

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Re: dont put a bearing in it!!!!!!!!
« Reply #5 on: May 17, 2016, 05:08:00 PM »

That's the reason why metal tips are not compatible with Short Circuit. It's just vibrating too much. Ben said he didn't know why.

vibration lol  ;D

What tip are you using? It can't be the bearing itself, but maybe there's too much weight at the tip area now?

Good to know a C-sized bearing will fit in there. I'm currently not inclined to swap tips on any of my Energia tops at the moment.

heres a pic, its the tip that came in the upgrade kit so its not just jack being wierd again trying to fit stb tips on everything  ;D
i tried my whip after putting the bearing back in and it worked fine  :o

http://i1365.photobucket.com/albums/r754/jack1861-1865/Mobile%20Uploads/image_zpshp8exqch.jpg
« Last Edit: September 22, 2017, 11:48:11 PM by ta0 »
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ta0

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Re: dont put a bearing in it!!!!!!!!
« Reply #6 on: May 17, 2016, 06:03:10 PM »

That is a fascinating video!
On my initial review of the Energia tops (link) I had mentioned that changing the tip could introduce a lot of vibration. Neff was of the idea, and I concurred, that the problem was that the top was too close to a sphere, so it does not have a clearly dominant axes of inertia. The slight difference in weight of the tip or bearing can make the moment around the normal axis and a perpendicular axis almost equal. In that case, any imperfection will be enough to move the principal axes to some random position away from the axis through the top.
I think that video settles it. Very interesting!
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Jack

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Re: dont put a bearing in it!!!!!!!!
« Reply #7 on: May 17, 2016, 06:20:10 PM »

That is a fascinating video!
On my initial review of the Energia tops (link) I had mentioned that changing the tip could introduce a lot of vibration. Neff was of the idea, and I concurred, that the problem was that the top was too close to a sphere, so it does not have a clearly dominant axes of inertia. The slight difference in weight of the tip or bearing can make the moment around the normal axis and a perpendicular axis almost equal. In that case, any imperfection will be enough to move the principal axes to some random position away from the axis through the top.
I think that video settles it. Very interesting!

ahh so that explains all the wierdness with the axis change  ???
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Daveid

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Re: dont put a bearing in it!!!!!!!!
« Reply #8 on: May 17, 2016, 08:21:54 PM »

I just tried it without the clip cap... seems to shift the weight enough to erase the wobble.
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like I always say:dead monkeys don't fly on sticks.

Neff

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Re: dont put a bearing in it!!!!!!!!
« Reply #9 on: May 17, 2016, 10:28:45 PM »

Yep, she's too round.  Also, single bearing tips wobble much more than double bearing tips. Moving parts on a top can induce chaos.

Aesthetically, I do love that shape but from a distance it just looks like a ball in the hand.
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Jack

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Re: dont put a bearing in it!!!!!!!!
« Reply #10 on: May 18, 2016, 11:57:14 AM »

I just tried it without the clip cap... seems to shift the weight enough to erase the wobble.

daveid with the saaaaaaaaaaaavvvvvvvve!!!! im too gun shy to try that now  :-[
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Jack

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Re: dont put a bearing in it!!!!!!!!
« Reply #11 on: May 29, 2016, 02:09:36 PM »

with the proper bearing setup its really amazing  :o
i litterally just learned multile succesive gyro flops just tday on this thing lol, couldnt manage it before on any of my other bearing tops @-@

https://www.youtube.com/watch?v=qYXMTzehxzU
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ta0

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Re: dont put a bearing in it!!!!!!!!
« Reply #12 on: September 23, 2017, 12:13:25 AM »

Kirk's question about the ratio of moments of inertia made me realize how easy it would be to measure this using the fishing line (torsion balance) method, as no calibration is needed for a ratio. If you have fishing line (e.g. 25 lb test) you can do it in 5 minutes (use adhesive tape to attach the line). So I decided to try our theory of the instability of the short circuit.

With the standard plastic tip, the ratio of longitudinal to transverse is around 1.1. Stable.
With a metal STEEL bearing tip (a prototype I had got) the ratio is 0.85. Stable (there are some vibrations but nothing unusual.
With an Aluminum bearing tip (the one that comes in the upgrade kit) the ratio is very close to 1.0! CRAZY MAD TOP!  :o

The STEEL tip (not counting the bearing) weighs 6.8 gr. while the aluminum tip weighs 2.3 gr.: a difference of just 4.5 gr. at the tip kills the top!  :o

Science is amazing!  :)

PS: When I originally reviewed the Energia Short Circuit I noticed the instability with a fixed tip aluminum tip (which I did not try this time because it's installed on a Big Shock). I also noticed that it was stable with the bearing tip, but I did not realize at the time that it was made of stainless steel (not magnetic) instead of aluminum.


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