Help me with my science project on yoyos! {merged}

Hi guys,
For a Yr 10 science experiment I was thinking about testing the difference between a regular ball bearing, a dif-e-yo konkave and a gold plated bearing. What do you think? Any thing you think I will need to consider? Thanks.

Define differences?

If you’re talking spin time, there won’t be a significant change… the shape of the bearing doesn’t really impact spin time, just how it interacts with the string.

The problem with yoyos are, they are thrown by hand, and for the most part it’s more on the player’s skill. So any this vs that comparison is hard to test consistently.
Some of the ‘simplest’ experiment involving yoyos is probably calculating their spinning momentum by comparing the weight distribution and coming up with certain numbers, but even that require pretty advanced physics understanding.

So, I’ve thought of this and I think a double blind test would work.
You are going to basically have to do a survey, because it’s too hard to control all the variables.

Get two yoyos that are the same. (IE two replay pros.)
Leave the centertrac in one, and put a flat in the other.
(For it to be double blind, you will have to get a third party to do this.)

Then have yoyoers throw the two yoyos without looking at the bearing to closely and get them to try and guess which is which.

The only problem with this, is you will need at least 10 people to throw it for the test to be interesting.

You’re right…it’s wouldn’t be near as interesting if only 9 people threw it :smiley:

Really now that I re-consider, it should go up to 11. :smiley:

Great idea! You might want to clean the bearings or something, so the lube doesn’t mess the experiment up.

Nearly impossible to implement sadly. As other have pointed out every variance and variable will come into play. Unless you made some simple machine to drop them all the exact same every time, youll get flawed results. If you get different throwers to help, one may throw a 30 second sleeper another might be able to throw a 3 minute sleeper with same equip.

String, string condition, string tension, response pads, response pad condition, lube (fresh, broken in, residuals left from cleaning, how they were cleaned…), humidity, heat, even minute difference in the tolerance of the bearings manufacturing all will affect the desired and accurate outcomes to test sleep times from some bearings against other bearings.

This is one of those very complicated answers to a very simple question. Honestly I dont know how it could be pulled off with even a remote degree of accuracy. Considering its for a 10yo science project, i wouldnt worry about it. They arent looking for exact info, just that you did the project.

Good luck!

What you can do is talk about different bearing sizes. Talk about Size A bearings and Size C bearings. Calculate out the moment of inertia of each, and explain the benefits and cons to each.

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This is all true. :frowning:

For clarification, the experiment I set out would be more to test the throwers than the bearing.
But I’m biased because I think most common yoyo logic is hearsay. (insert sad bear meme)

No, no, no. You need at least 12.

Use identical yoyos and new strings of the same length. Let the yoyo roll off some kind of incline. It won’t spin too fast, but that shouldn’t matter if you are just comparing bearings.

Doing this means the yoyos will get an equal spin (from rolling down the same surface from the same distance, no need to worry about thrower difference.

The trickiest part would be getting the wound up identically, but you could count the winds to get it pretty close.

Was going to drop them at the same time. Ugh. Idk now

You mean yr 10 right? Not 10 yo.

Year ten is very different from ten year old, but that’s not typically how we say it in the states so that might have been the confusion. We usually say tenth grade, or sophomore.

The only problem I see with dropping the yoyo from a machine is that most of the benefit of a string centering bearing is gained from I staying centered during a trick.

I’m not trying to dissuade you, I’m just saying you might have to be clever about what you test for and how.

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My brother is currently doing a project on the spin time of different yoyo shapes. Although you would need to take out all other variables. To do it correctly, you would need to use the OneDrop Benchmark series, as they are all the same except for shape. Bearing just doesn’t matter as much.

And shape probably matters less.

Cant afford them mate


Mass is probably going to be a bigger factor than shape.

What I plan to do is drop the yoyo by letting it fall off of a table and timing how long it spins for.
My question is this:
Since ceramic bearings are supposed to reduce friction, does it matter that I am not throwing the yoyos with as much force as possible?
What I mean is, for example the steel bearing say it spins for 15 seconds when dropped, but 3m for a strong throw.
But the ceramic bearing spins for 16 seconds when dropped but 3m 30s for a strong throw.
Would something like this happen? Or is it irrelevant. Help pls