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Author Topic: Regenerability of a top!  (Read 625 times)

paxl13

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Regenerability of a top!
« on: January 21, 2019, 02:19:37 PM »

Hi y'alls... Forum seem sadly a lil' slower, let's try to get some life in here :P

I was wondering what makes for a good regen top.. Here  is a pic of 3 of my beloved tops, on the left this is Jose free top from thingiverse with the YYF tip, center is QSH and right one is hornet..





Now, Jose's top is nearly impossible to regen at very low speed ( albeit I'm getting better at but still ) it is FAR more harder than say the QSH & the hornet.
What impacts the regenerability (?) of a top. Is it only the tip shape, or the weight distribution has an effect ?

Thanks for your inputs guys!
paxl
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ta0

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Re: Regenerability of a top!
« Reply #1 on: January 21, 2019, 06:40:06 PM »

I'm not sure if we understand completely the magic, but people have mentioned the regeneration genie giving them a visit  :D

Regeneration happens when the string slides faster than the velocity at the surface of the tip, so the friction force is in the direction that speeds up the top (let's call it "positive friction"), or at least at the same speed (rolling condition).

When I first developed the diabolo tip (independently from Salvador who came up with the same design), my theory was that if I got the neck of the tip smaller, the tangential velocity would be slower and it would be easier to achieve positive friction with the string. In hindsight, perhaps the biggest benefit was that the "negative" friction (when the string didn't slide fast enough) was lowered. This is specially true for on-string regenerations.

A top that has more rotational inertia (e.g. bigger) would also spin slower, so achieving positive friction should also be easier. However, you need more torque to spin a more massive top, so it can be detrimental if the size of the neck or string are too small.

Now, Jose's top is nearly impossible to regen at very low speed
I'm not sure what's the explanation. Perhaps for regeneration you need to achieve the rolling (no slippage condition, so we are not really talking about friction), and the string is too fast.  :-\
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Jeremy McCreary

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Re: Regenerability of a top!
« Reply #2 on: January 22, 2019, 02:52:12 AM »

Now, Jose's top is nearly impossible to regen at very low speed
I'm not sure what's the explanation. Perhaps for regeneration you need to achieve the rolling (no slippage condition, so we are not really talking about friction), and the string is too fast.  :-\

In the no-slip rolling regime, you'd definitely have some static friction between, say, cotton string and the metal fixed tip. Maybe also some rolling resistance due to sinkage of the effectively rigid tip into the string segment currently in contact.
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paxl13

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Re: Regenerability of a top!
« Reply #3 on: January 22, 2019, 06:00:43 AM »

quote author=ta0 link=topic=5624.msg59694#msg59694 date=1548114006]
I'm not sure if we understand completely the magic, but people have mentioned the regeneration genie giving them a visit  :D
[/quote]

Even with my scientific mind, My mind don't warp still don't wrap around the fact that it actually works.. so yeah the genie came by my house ( especially giving me snapstarts less than a week ago ) but I'm still trying to get a grasp on it scientifically...

When I first developed the diabolo tip (independently from Salvador who came up with the same design), my theory was that if I got the neck of the tip smaller, the tangential velocity would be slower and it would be easier to achieve positive friction with the string. In hindsight, perhaps the biggest benefit was that the "negative" friction (when the string didn't slide fast enough) was lowered. This is specially true for on-string regenerations.

Would that mean that a slightly smaller neck on Jose's top would help her be more regenerative ?
If I had more than one tip I'd try it out ( it's just the matter of reshaping the tip in my drill.. this is easy to do! )
Or, being an alu tip. can it actully be b/c of friction ( or lack thereof ? )

PS: might just be me that my regen aren't on pars per say :)

This topic absolutely puzzle and mesmerize me... Like I mentionned, I can do it yet I still can't believe that it's possible :P
Cheers
paxl
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jmadrigal

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Re: Regenerability of a top!
« Reply #4 on: January 22, 2019, 09:35:58 AM »

The small top I uploaded online is a great wire walking top. Tricks like Skywalker are great with this one. It regenerates fine but like any smaller top you have to be quick.
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paxl13

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Re: Regenerability of a top!
« Reply #5 on: January 23, 2019, 08:49:05 AM »

The small top I uploaded online is a great wire walking top. Tricks like Skywalker are great with this one. It regenerates fine but like any smaller top you have to be quick.

It does regen fine.. but it's quite harder to regen properly than say a QSH which is the same size... So what I've been wondering, is that, is is only due to tip neck size? Any idea, or it's just me
that is not good enough. 

Second question: Is smaller string going to be better at regens? This morning to practice my snap starts with my QSH I took my hornet string ( my accident ) and suprisingly, I was flying
through regen no problems... I'm maybe trying to see this with a too much scientific mind :P

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jmadrigal

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Re: Regenerability of a top!
« Reply #6 on: January 23, 2019, 10:13:43 AM »

The quick silver is definitely a superior regen top to the small top I uploaded. If I didn't make my 3.2" tops I would be using quick silvers. Quick silvers weigh more and cut through the string better for regens but do not wire walk as well.
I think the weight of the top and the opening on the neck of the tip dictate the string thickness.
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Jeremy McCreary

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Re: Regenerability of a top!
« Reply #7 on: January 23, 2019, 05:01:56 PM »

I think the weight of the top and the opening on the neck of the tip dictate the string thickness.

Some very interesting trade-offs here from an engineering standpoint. Questions for anyone with regen experience...

Q1: For a given player, is there a consistent sweet spot in weight, or does optimal weight depend on the top somehow?

Q2: Workable weight range for effective regeneration?

Q3: Which neck measurement(s) count most WRT optimal string diameter? Neck diameter at narrowest point? Neck angle at narrowest point? Something else?

Q4: Is the goal in Q3 to optimize string-neck friction? Something else?

Q5: Can there be too much string-neck friction?

Q6: What rule of thumb do you use to predict optimal string diameter from key neck measurements?

Any info greatly appreciated!
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ta0

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Re: Regenerability of a top!
« Reply #8 on: January 23, 2019, 07:30:38 PM »

Jeremy: I was just half kidding when I mentioned the regen genie. Regeneration is still more of an art than a science.
I still remember when I was trying to learn regenerations and they seemed almost impossible. But now it feels almost like the top regenerates no matter what I do ;D

There are many types of regens tricks and the answers could be different for several of the questions.
Small and light tops get difficult to regen, but I would never bet against Gus.  :D
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Jeremy McCreary

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Re: Regenerability of a top!
« Reply #9 on: January 24, 2019, 01:29:25 AM »

Jeremy: I was just half kidding when I mentioned the regen genie. Regeneration is still more of an art than a science.... There are many types of regens tricks and the answers could be different for several of the questions. Small and light tops get difficult to regen, but I would never bet against Gus.  :D

Any other good rules of thumb for this black art of top and string selection?
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paxl13

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Re: Regenerability of a top!
« Reply #10 on: January 24, 2019, 05:11:04 AM »

I think the weight of the top and the opening on the neck of the tip dictate the string thickness.

Some very interesting trade-offs here from an engineering standpoint. Questions for anyone with regen experience...

Q1: For a given player, is there a consistent sweet spot in weight, or does optimal weight depend on the top somehow?

Q2: Workable weight range for effective regeneration?

Q3: Which neck measurement(s) count most WRT optimal string diameter? Neck diameter at narrowest point? Neck angle at narrowest point? Something else?

Q4: Is the goal in Q3 to optimize string-neck friction? Something else?

Q5: Can there be too much string-neck friction?

Q6: What rule of thumb do you use to predict optimal string diameter from key neck measurements?

Any info greatly appreciated!

Right on, another engeneer that try to pin point regen like I am :P Here is my answer to the best of my knowlege

R1 : In my oppinion, I think is has to do with a size to weight ratio because both the Hornet ( 70g ) & the QSH ( 115g ) are super regenerable...

R2: No idea.

R3: That's what I was after ( I'd love to have a metal lathe & make tip for the QSH say and see what happen )

R4: No idea

R5: No idea

R6: No idea

My answer are sadly not very useful

Jeremy: I was just half kidding when I mentioned the regen genie. Regeneration is still more of an art than a science.... There are many types of regens tricks and the answers could be different for several of the questions. Small and light tops get difficult to regen, but I would never bet against Gus.  :D

Any other good rules of thumb for this black art of top and string selection?

lots, lots, LOTS of practice.. I'm with ta0. it's an art... the subtility between slowing down the top and regenerating it is very very small...

Cheers, hopes that helps!
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