A few of us had a rousing little technical discussion/class/lecture yesterday evening on the shop cam chat. The topic of discussion? Runout, specifically, radial ball bearing runout. What exactly is runout, you may ask? If you were there, you now know! If not, do yourself a favor, do a little research, google it, read a ball bearing technical manual, or whatever, and if you have any questions, feel free to post them here. We will do our best to educate and enlighten one and all!

Not only is the shop cam a good hang for the community, it can serve as technical sounding board , lecture hall , even a philosophical debate arena . Thanks, 1Drop, for providing this unique opportunity to all of us!

db

I'm constantly amazed and just how difficult it is to produce consistently balanced metal yo-yos. The tolerance window is so micro and out of proportion to the resulting product: a toy. The bearing post requires aerospace type accuracy.

The consumers of these toys, whether they know it or not, have to come to have very high expectations. It's a good thing (and kind of unique) to have a customer base that is so hungry for knowledge about how their toy is made.

The design parameters for a metal yo-yo present contrasting goals which is why consistent production is so difficult.

1. Balanced (requires a tight press fit bearing assembly)
2. Serviceability (requires a looser fit bearing assembly so the bearing can be removed by the customer)
3. Color/Finish Variety (variance is color anodizing makes it more difficult to get the bearing assembly the correct size)

Our customers require all three of the above. If we could make our yo-yos just one color and a press fit bearing then they would be the smoothest yo-yos possible. However, bearings need to be serviced and people like colors so some of that accuracy is sacrificed.

We LOVE the challenge of being able to meet these requirements and still produce consistently smooth yo-yos. And we LOVE having the technology (internet, cam, etc) to be able to share it with you all.

I guess i will never know the tech behind the yoyo. I cant even fully understand how to use the cam j/k

We do love the technical aspects of our little community. And it's an educational thing too Good for kids, good for adults, win sauce all the way round. I'll add what I can when I can but DB is the technical authority. Dammit Jim, I'm a doctor not a mechanical engineer!

Added the simplified business equation to the technical requirements...

And in order for the yoyo company to stay in business there is a fifth criteria (and Mr. Machinist, I'm NOT referring to scotch!)

5. Makes money (well, at least a little ) for the manufacturer

So the manufacturer has to balance even more requirements and details than the customer in order to deliver everything the customer needs, wants, and expects...and them some (in the auto business this is sometimes referred to as "surprises and delights!").

db

DB,

You are absolutely correct. I was limiting my discussion to the technical side but yes they can't really be separated and we're trying to do all of the above and more

Perhaps One Drop is largely responsible for the affordable expectation (although consumers of all products are always seeking a bargain).

Fun stuff

Actually, the business side can be more complex than the technical side. At least on a theoretical level. It's amazing how much time and energy these two guys spend just thinking strategically about their business, their customers, their responsibility to the community, production schedules, technical matters, intellectual property strategies, public and private policies, and so much more. My hats off to them, as it is to almost anyone that runs a successful business. And by successful I don't just mean profitable. I mean that it has to be a genuinely worthwhile endeavor. One that balances the needs of the three main constituents, employees, customers, and owners/shareholders/investors. It also has to contribute in a positive way to the greater community, in other words you have to be a good corporate citizen. I think Dave and Shawn are succeeding at this admirably. And this is coming from someone who once owned and operated a business with 25 employees.

u guys are 100% right!

yeah that was quite to convo in that chat room glad i figured that out kinda. to be back on topic here DB you mentioned run out but wheni think run out i mean balls litteraly like breaking the bearing because of such high frictions for such high rpms. i think thats where i got mixed up and miss interpreted runout of a bearing is it one rotation or is it MANY?

You would typically measure a single bearing for one revolution. In order to report a "better" value, a bearing manufacturer would measure hundreds or more samples (different bearings) in order to give a statistical average.

db