More than just bricks fitting into each other at a superficial level, it matters how firmly they fit together, and it's one of the areas where LEGO is generally superior to the similar types of bricks.
A detail I didn't realise until I was an adult was the difference between the black and grey technic connecting pins. They look interchangeable, and for a lot of things they are.
But there's a fraction of a mm raised lines on the black one, and it's enough to produce significantly more friction, and that difference is utilised in designs.
And apprently there's now a new version of the black one, and people notice these things, and measure them - this article gives an idea of just how these tiny changes, well below tolerances for some of the "knockoffs", can produce a different effect:
Do you mean between black and light grey? Light grey pins have always been the kind you use for rotating connections (low friction), whereas black was for non-rotating ones (high friction). Newer blue pins are also high friction, IIRC. I haven't bought new lego technic in a while, so I don't know if there's been any new colours added
EDIT: I think I also had some dark grey pins, but I don't remember if they were high or low friction
My memory of twenty years ago says the dark-grey pins were 1 stud wide on one side, and half-wide on the other, and low-friction like the light-grey ones.
> it's one of the areas where LEGO is generally superior to the similar types of bricks
Imho, this is, objectively, not true (anymore).
Pantasy with GoBricks are superior in coloring and fit; Cobi are excellent for things that should not be taken apart anymore (like tank models); Lumibricks are excellent in fit and have amazing illumination solutions that are lightyears (haha) ahead of lego.
I got the Pantasy Neo Geo set a while ago, and was pretty blown away compared to the better known imitators that have been available at retail. The mechanics are not as robust as I’d expect from Lego, but it was about a quarter of the price and externally looks as good with some really fun and well thought out details.
Interesting - never come across Pantasy/GoBricks, or Lumibricks but then it's a few years since my son decided he was too old for LEGO, and I see Pantasy is just a few years old, and Funwhole/Lumibricks just a few more. Great if there are more options of similar quality.
But "should not be taken apart anymore" fits into an entirely different category for me. If you don't need to be able to take them apart any more, it fundamentally changes requirements.
Not OP but from my experience, the LEGO I had in a bin since I was a kid still fit perfectly with LEGO I'm buying for my kids 30 years later. That's unbelievably impressive to me.
Lego from my youth, which was a hand-me down at the time, doesn't fit well with new lego. So it might be 40 years old, (which seems like a long time until you actually reach that age!)
I think it's more likely do to plastic aging than the original tolerances though.
To add even more - I was handed down Lego that belonged to my mom in the 60s, played with them through the 80s and 90s, and now my kids have them today. I wouldn’t be able to tell you which were hers and which were mine.
They’ve been around over 90 years and have been making plastic bricks since the 1950s and are arguably the most successful children’s building toy product in history. They have amazing brand recognition, and beyond the toys, they have successful video games and movies.
According to my local news outlet, they’re up 12% in revenue growth in the last year (which outpaces the rest of the toy industry) and up 1,200% since 2004.
Ha, I noticed this too! And even my 3 y/o picked up on this.
We have a set (something with Spiderman IIRC) that attached wheels with yellow pins that allow for better rolling of wheels. The black pins are too tight for this indeed.
A detail I didn't realise until I was an adult was the difference between the black and grey technic connecting pins. They look interchangeable, and for a lot of things they are.
But there's a fraction of a mm raised lines on the black one, and it's enough to produce significantly more friction, and that difference is utilised in designs.
And apprently there's now a new version of the black one, and people notice these things, and measure them - this article gives an idea of just how these tiny changes, well below tolerances for some of the "knockoffs", can produce a different effect:
https://ramblingbrick.com/2021/01/27/what-if-they-introduced...