Author Topic: diabolo speed wobbles - why does this happen ?  (Read 4561 times)

chitralview

  • Thanks: 0
diabolo speed wobbles - why does this happen ?
« on: August 14, 2008, 07:03:50 pm »
I had a question about diabolo speed wobbles. Why does it happen?

If you REALLY, REALLY whip (speed up) some 5 inch diabolos, it will develop speed wobbles. Can anyone explain this?

Thanks   

fzzyrn

  • Thanks: 4
Re: diabolo speed wobbles - why does this happen ?
« Reply #1 on: August 14, 2008, 07:39:20 pm »
it's not tightened enough. try tightening it a bit

chitralview

  • Thanks: 0
Re: diabolo speed wobbles - why does this happen ?
« Reply #2 on: August 18, 2008, 05:44:41 pm »
I tightened the nuts.  It still wobbles

Diabolo Bro

  • Thanks: 12
Re: diabolo speed wobbles - why does this happen ?
« Reply #3 on: August 18, 2008, 08:46:28 pm »
is it wet? is the string wet? what kind of diabolo? how old is it? did you tighten it correctly, does it make noise while it isn't wobling? are the cups warped?
98 percent of the population will die at some point in their lives.

n3mo

  • Thanks: 7
Re: diabolo speed wobbles - why does this happen ?
« Reply #4 on: August 18, 2008, 10:13:24 pm »
as it wobbles, try holding your stick to it until it evens out, it should stay stable. if not...you probably messed something up with the yoyo; tightening, warping, uneven/unbalanced cups, etc.
- Princeton Juggling Club -

Ethan

  • Thanks: 10
Re: diabolo speed wobbles - why does this happen ?
« Reply #5 on: August 19, 2008, 12:40:18 am »
is it wet? is the string wet? what kind of diabolo? how old is it? did you tighten it correctly, does it make noise while it isn't wobling? are the cups warped?
ease up on the questions Al haha, if its dirty it might wobble a little too, try cleaning it too
"In a ball and stick model, what do the balls represent?"  -Bio Teacher

Pete

  • VotW Contributor
  • Thanks: 8
Re: diabolo speed wobbles - why does this happen ?
« Reply #6 on: August 19, 2008, 09:06:55 am »
The way I see it, if the diabolo isn't perfectly circular, speeding it up will warp its shape further making it wobble more. More flexible cups will mean more warping, so more wobbling.Thats why Harlequins go absolutely mental at high speeds. Most diabolos aren't perfectly circular so most diabolos have some sort of high speed wobble. Makes sense to me.
The tallest trees from acorns grow.

Aaron Z

  • Thanks: 5
Re: diabolo speed wobbles - why does this happen ?
« Reply #7 on: August 19, 2008, 09:14:35 am »
...If a diabolo is spinning very quickly, the cups will actually even out, not warp further. Even more-so if the diabolo has softer cups.

The faster the diabolo spins, the more centripetal force pushing outwards on the cups, making them eventually fall back into shape.

Pete

  • VotW Contributor
  • Thanks: 8
Re: diabolo speed wobbles - why does this happen ?
« Reply #8 on: August 19, 2008, 10:10:00 am »
I disagree, but i am no physicist. Surely the parts that start on the outside of the cup as it were (i.e. the bits that stick out from a perfect circle) will have a greater force affected on them, as they are on the are on the outside, so these parts will stretch further than the parts that aren't sticking out, exaggerating the warped shape. This is just how i've always seen it, and its made sense up to now. I'm sure theres people on here who can explain this better than me.
The tallest trees from acorns grow.

Sean

  • Administrator
  • Thanks: 241
Re: diabolo speed wobbles - why does this happen ?
« Reply #9 on: August 19, 2008, 12:55:57 pm »
I used to see this happen with my first diabolo - an old (~18 years?) Mr. Babache diabolo that wasn't perfectly true. As I see it, it's a frequency thing. Your diabolo wobbles a bit - some more than others. When the rotational speed of the diabolo causes those wobbles to match each other as they go around they get amplified, quickly getting out of control. This is called resonance frequency.

Katana

  • Thanks: 2
Re: diabolo speed wobbles - why does this happen ?
« Reply #10 on: August 23, 2008, 09:06:35 pm »
I've experimented a bit with this and the result always seem to be weight distribution assuming the diabolo is prorperly tightened.  If one half of the diabolo is heavier it will wobble, when the weight difference increases the wobble happens at slower speeds. Quite easy to test yourself, tape a coin into the cup of a diabolo and start using it, the wobble is quite obivous, the diabolo will also start to twist around the string.

Smaller diabolos seem to be more prone to this than larger ones, i think it's because the weight of the smaller diabolos is the cause, since a minor weight difference is more pronounced on an already lighter object. Wear and tear takes it toll on diabolos, tiny bits get ripped off whenever you drop it, gouges if you drop it on a rough surface, that tarmac ruined my spinabolo. On my old battered Circus diabolo i can make it wobble, but it requires a speed that tires me out to achieve, on a cheapo plastic diabolo i can do it easily.

Any moving object that isn't well or perfectly balanced will always be unstable is my simple answer.
Not sure how much of that was BS but it's my best explanation.

Diabolo88

  • Donator
  • Thanks: 30
Re: diabolo speed wobbles - why does this happen ?
« Reply #11 on: September 12, 2008, 09:30:01 am »
Doesn´t all diabolos start to wobble at high speeds? I have never managed to not get a diabolo wobbly :P.

Aaron Z

  • Thanks: 5
Re: diabolo speed wobbles - why does this happen ?
« Reply #12 on: October 08, 2008, 10:57:10 am »
Doesn´t all diabolos start to wobble at high speeds? I have never managed to not get a diabolo wobbly :P.

Taibolos and Suns, man. They practically glide along the string, especially with Taibolos.