Strange choice of title, since LEGO doesn't snap-fit. LEGO blocks join by press-fit, where tight tolerances ensure friction between the connecting surfaces. This as opposed to the expansion and contraction of intentionally miss-sized joining surfaces – causing the snap of snap-fit.
I'm not smart enough to understand the math in the paper, but I'm able to see that the illustrations match the minifig hand example. This snap fit is present in a lot of LEGO pieces. I'm sitting next to SF, Shanghai, and Kyoto architecture sets, and the 3-in-1 deep sea creatures set, all of which use different snap fit pieces. However, I can understand the confusion given most people's first image of a LEGO piece.
> Wada is also interested in investigating what he calls the "type-II snap" which has the opposite qualities: it’s easier to pull apart and challenging to push together.
What is a good real world example of this? Maybe something like a spring loaded system which takes force to load but then is released with simple trigger.
Some of the latches on expensive coolers are intentionally hard to close, leading users to slam them, which leaves the user with the feeling of the cooler/latch being rugged (and hopefully worth the extra price of admission). These slam latches are much easier to open than to close.
Surely it’s not just to “feel rugged”. The rubber seal of a cooler lid is essentially a deformable spring which must be compressed in order to form an effective seal.
When you're closing a cooler you're compressing the gasket. When you open it you're releasing the gasket. It's not a cynical marketing ploy like you describe - it's functional.
I don't know what you mean sorry? I don't know what differs at price points, and I don't know what Yeti is. I just know the coolers I have have gaskets which get compressed when you close them. That's why they pop open when I unlatch them, and why it takes effort to close them.
> It's not a cynical marketing ploy like you describe - it's functional.
I believe the parent comment is saying that the closing-force varies closely with price; as price goes up, so does the force required to close it. While there may be a functional reason for some difference between opening-force and closing-force, you wouldn't expect that functional reason to result in that correlation so strongly, and that the majority of the difference in force at high price points is a cynical marketing ploy. (I'm not sure I buy that, it makes sense to me that a more expensive cooler has a thicker gasket to get a better seal.)
I love this style of physics using simple clever experiments to get new insights into seemingly understood systems. To my delight the original paper appears not be be paywalled: https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.125.194... now I just need to find time to read it.
I just skimmed the paper but I don't see what's novel here. Engineers design clips all the time. My company produces off the shelf software to help them to this - modelling the geometry, friction and elasticity.
It looks like this is just a fun investigation into something that's novel to the author but not to the world. Shouldn't it be a blog and not something with a DOI?
