# Engineering and physics of yo-yo design

I was wondering if anyone could explain why and how weight placement and shape effect how a yo-yo plays or feels?
What gives a yo-yo the floaty feel? And what makes a competition yo-yo more suited for competition than another yo-yo? Is it aerodynamics? Can spin or shape generate any lift like a wing?
I don’t know. Hopefully someone can educate the few of us that find this stuff interesting. I’m guessing someone out there has made or played a ton of shapes and weights and knows the answers.

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I’m not a spinning object engineer.
but from my knowledge, center of gravity, speed and mass have the biggest affect on how an object moves. other things like shape design can affect air displacement. again- not an engineer lol

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Interesting topic! Here’s another thought: Why don’t yo-yos have dimples like a golf ball? Theoretically it would allow them to spin longer and faster since aerodynamic drag would be decreased.

Ivan

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Great idea.

Rim weight is preferable for performance based yoyos as added rim weight means a higher moment of inertia. Moment of inertia is basically a measure of how far mass is from the center, and a higher moment of inertia allows for yoyos to spin longer as they maintain their angular velocity for a greater amount of time.

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Do you think shape effects performance? Organic vs V shapes for example. If they had the same surface area, weight, and diameter? And assuming that you could get the weight distribution the same. Would they play the same?

they don’t have dimples because the man is trying to keep us down.

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Definitely not.

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Crazy! You ever play one of these Ed?

How do you adjust the response? Different size o-ring?

LF: Roo-yo

Any color, any condition, PayPal ready.

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No Doubt! I wonder how many were made?
The wiki info says 66gram weight, but it looks like 69.5 on the tube in the pic.

A competition yoyo is typically designed to minimize sleep loss while fitting within some comfortable boundary of size and shape for the current set of popular tricks.

The shape of the yoyo impacts this a lot - especially close to the bearing where the most string contact happens. The shape near the rims affects how much mass you can add efficiently, and how comfortable it will be.

Some design features that minimize sleep loss making certain yoyo tricks more difficult. For example, very low walls and a wide gap together can make rejects and regens more difficult. These same features also allow more layers of string more easily. There are many other tradeoffs like this.

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Aerodynamics has little to no effect on a yoyo. The performance is primarily dominated by weight and it’s distribution. Skin friction (aerodynamics) has a negligible effect on spin time.

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That was amazing! I now know everything i need to know… I’m going to design a yoyo

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You can’t talk about Yo-Yo design without bring up BiST

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They sure are beautiful. Works of engineering art!