Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Lego's 0.002mm specification and its implications for manufacturing (2025)

thewave.engineer

Post reply on HN
Print view View original

71–80 of 343 posts

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#71

Post by rkangel »

lich_king wrote: post #49

This is an LLM-written article. It also doesn't say anything . I get it that it's a cue for us to reminisce about childhood and say that LEGO isn't what it used to be, but we're being played for clicks. Open the article and look for a single statement that actually tells us something meaningful. It's just a sequence of impressively-sounding factoids like this: > A 2x2 brick can withstand over 4,000 Newtons of force,…

I agree, it doesn't say a lot. It also very confidently specifies a series of tolerances with no citations.

Lego does indeed have very tight tolerance, but I don't know if the numbers are in the public domain.

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#72

Post by antonyh »

Thlom wrote: post #46
wek wrote: post #18

For me, the beauty of Lego was just a huge bin of interconnectable parts that I used to make whatever my imagination came up with. For my kids, Lego is pre-built model airplane set that they build one time and then display. I liked my Lego better :)

You can still buy LEGO Classic which is just a bunch of bricks.

From experience there's a motivation, almost a compulsion, to follow the instructions to build the cool thing. Then... they sit there, those bricks never taken apart.

That compulsion doesn't seem present in freeform building, and there's been zero interest in it in our household. I know that's not true for all, but it seems like a lost art. Maybe it's because the IP sets show how but not the why it's constructed in a certain way, so given a bag of Lego most wouldn't know the process of creating something they can see in their minds eye within the constraints of the available bricks.

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#73

Post by MarsIronPI »

wek wrote: post #18

For me, the beauty of Lego was just a huge bin of interconnectable parts that I used to make whatever my imagination came up with. For my kids, Lego is pre-built model airplane set that they build one time and then display. I liked my Lego better :)

Maybe Lego needs to manufacture sets that are just "collections of bricks". In fact, I think they did that at least for a while. I know my past self would have loved to have a few sets that when put together would provide the kinds and variety of pieces used in books such as The Lego Play Book.

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#74

Post by ryukoposting »

bdunks wrote: post #41
scatbot wrote: post #12

Lego is one of those companies that is simultaneously amazing and kind of sucks. On one hand the core product is incredible. The tolerances on the bricks are micrometer-level precision and the fact that pieces from the 70s snap perfectly into ones made today is mind blowing. On the other hand, a lot what the company does today just sucks. Set prices are outrageous. Printed bricks get replaced with stickers and many s…

Agree. They seem to have a “price per piece” equation. Perhaps as a result, the 5+ sets are made of hundreds of small pieces. Older sets had larger foundational and platform pieces which gave a good starting place for new creative builds. Today, airplanes fuselages, wings, and car chassis are instead built up piece by piece. It’s hard for my 6 year old to start creative builds that are stable when he hardly has any p…

Several years ago I wrote this reddit post analyzing LEGO piece pricing: https://www.reddit.com/r/lego/comments/1328f52/detailed_lego...

It's a little out of date, but the conclusions are still relevant.

Main things of note: Brickheads are pretty economical as a "parts pack." No significant correlation between per-piece pricing and IP licensing (except for Star Wars). Star Wars and City sets are overpriced.

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#75

Post by thowawayko1 »

butILoveLife wrote: post #10

After working in automotive, this is less impressive than it appears. Tons of dimensions on 100k/yr injection molded(and otherwise) parts have similar dimensions. (Although admittedly, after testing in pre-production, I don't know if they are tested again and have drift) Lego has been making the same parts for decades and their parts are extremely simple. I imagine their 1-off parts for intellectual property based se…

After working both in automotive and at LEGO, I think LEGO is more impressive tolerance wise when it comes to molds, molding and tolerance quality control.

Also to correct you, LEGO has been making most of the parts for decades, some have had changes due to new materials (which you can read upon online) but besides the ones that remained the same (not really), many new system elements got released in the last decades and new I.P tied elements get released on a yearly basis.

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#77

Post by rkangel »

The tolerance for interference fit ("clutch power" in Lego terminology) is important, but that's fairly simple. It's the cumulative tolerance when you assemble large structures that's important. Knockoff bricks can be fine for the first few you assemble, and then as the structure gets larger things don't quite fit together.

Also interesting is that in very large models, there is decoupling between sections. Lego has design rules for how large a well connected chunk of Lego can be, which are driven by the tolerances. Above that you are then loosely coupling those large "chunks".

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#78

Post by wongarsu »

bluGill wrote: post #61
scatbot wrote: post #12

Lego is one of those companies that is simultaneously amazing and kind of sucks. On one hand the core product is incredible. The tolerances on the bricks are micrometer-level precision and the fact that pieces from the 70s snap perfectly into ones made today is mind blowing. On the other hand, a lot what the company does today just sucks. Set prices are outrageous. Printed bricks get replaced with stickers and many s…

I heard your same rant in the 1980s - only small details have changed (not mindstorms then ...) But kids who want to build have always been able to, and most sets mix and match for those kids.

> I heard your same rant in the 1980s

The two options would be that either the perception is unsubstantiated but persists, or there has been a continuous decline for the last 40 years. I'm strongly leaning towards the latter. I also having the same issues in the 00s looking at old sets from the 80s, and looking back now the 00s look much better than what we have today. Obviously not in every way, and not all recent sets were bad. But overall I have the feeling that there's been a steady trend that the bricks got better but the sets got worse

Re: Lego's 0.002mm specification and its implications for manufacturing (2025)

#80

Post by foobarian »

scatbot wrote: post #12

Lego is one of those companies that is simultaneously amazing and kind of sucks. On one hand the core product is incredible. The tolerances on the bricks are micrometer-level precision and the fact that pieces from the 70s snap perfectly into ones made today is mind blowing. On the other hand, a lot what the company does today just sucks. Set prices are outrageous. Printed bricks get replaced with stickers and many s…

Oddly enough I found the Duplo line much more fun to play with as our kid went through the blocks years. You could build something substantial with fewer block clicks, there were fewer different types of blocks, they were less fiddly and prone to vanishing into rugs/carpets, etc. Also the proper Legos tended to be sets which makes it very stressful to mix them into a misc bag.
Post reply on HN