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Lego's 0.002mm specification and its implications for manufacturing (2025)
- exabrial 7mo agoBackwards compatibility is something lost today. Incredible they've kept it this long.
- Normal_gaussian 7mo ago"that familiar click is the sound of a carefully engineered interference fit designed to hold firm but still be easy for small hands to pull apart." My recent experience calls bs on pulling them apart.
- intrasight 7mo agoThe tolerance is definitely more applicable to the getting them apart then putting them together.
- doubled112 7mo agoI always remember the small, weird pieces being hard to get apart. What I don't remember was every kit being made up of so many small, weird pieces.
- ralferoo 7mo agoWhen I was a kid, the first "special" Lego kit I remember was the Star Wars sets in 1983 (and especially that everybody wanted a Millenium Falcon but I didn't know anybody who had parents that could afford one!) Apart from those Star Wars kits, everything I had were generic blocks and strips (not sure what they're called, the ones that are 1/3 the height of a block) and some different designs of people. The closest I had to previous special sets was a town thing that my brother and sister had before me (they were 10 years older), which was a bunch of large floor tiles with roads and grassy areas with studs, some flowers pieces (single stud) and a handful of special buildings. But they were designed to be relatively generic, and the fun was using those building blocks to make a new city each time, not trying to recreate exactly someone's model. Apart from the flowers and the men, basically everything was a standard part, except perhaps a different colour. When I was a teenager, the trend had become sets with lots of specialised parts for one specific model, such that they didn't really make sense as generic pieces. I enjoyed the technics kits because the early ones were just generic building blocks (apart from the wheels and rack and pinion, but again they could be re-used in lots of subsequent designs), but more and more the kits in the shops were for specialised models with unique pieces that were never designed to fit aesthetically with anything other than the model they came with. I'm sure _some_ people built other things with them, but equally I'd bet than probably 90% of those kits were built exactly once following the instructions and then never disassembled again.
- bena 7mo agoThe elements that are 1/3 the height of a brick is a plate if it has studs, and a tile if it does not. Lego did not have Star Wars sets until 1998. The original Lego Millenium Falcon set 4504 would have retailed for right around $100. Which was high, but just as high as the bigger Castle sets at the time.
- SoftTalker 7mo agoThey definitely had lunar/space themed sets in the '80s, but they were generic (at least the ones I had). I don't recall when the Star Wars sets came out, they might have been one of the first cross-promotional tie-ins that Lego did?
- bena 7mo agoStar Wars sets started coming out in 1998. They weren't the first licensed sets, but the first fictional license. Prior to Star Wars, they had Shell, Exxon, and Esso branded sets. I think sometimes they licensed the Ferrari brand as well. And yes, Lego has had a Space theme since the late 70s. But it was a general "Space" theme. They would later make Space Police, Blacktron, Magnetron, etc. But actual Star Wars was 1998. I have some of those sets. It was a big deal to get an actual lightsaber hilt and blade.
- ralferoo 7mo agoVery interesting. Googling shows some generic space themed things from the 80s like you say, but no Star Wars. I guess my old age is finally catching up on me and my memories have all blurred into one. I did find a Millennium Falcon from 1983, but it's definitely not Lego.
- Zanfa 7mo agoHaving grown up playing with LEGOs, I can still distinctly remember the feeling of sore fingers pulling tiny pieces apart after a long session. It wasn't until a few years ago I learned there's an official brick separator tool [1]. Would've changed my life as a kid. [1] https://www.lego.com/en-us/service/help-topics/article/lego-classic-brick-separator https://www.lego.com/en-us/service/help-topics/article/lego-...
- bombcar 7mo agoThere are multiple brick separators, with different strengths and weaknesses.
- jjk166 7mo ago> It wasn't until a few years ago I learned there's an official brick separator tool You mean a little brother?
- mrsvanwinkle 7mo agoOkay this lit up my life for the day
- WillAdams 7mo agoCurious how this might have played out over the long-term with their licensed/abandoned/revived/then bought to kill permanently "Modulex": https://archinect.com/features/article/149974598/the-brief-and-wondrous-life-of-modulex-lego-s-building-system-for-architects https://archinect.com/features/article/149974598/the-brief-a... I wish one of their competitors would take up this dimension standard --- it would be a lot more useful for making structures which interact across dimensions/rotations.
- vidarh 7mo agoMore 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: https://ramblingbrick.com/2021/01/27/what-if-they-introduced-a-new-technic-pin-and-nobody-noticed/ https://ramblingbrick.com/2021/01/27/what-if-they-introduced...
- rrr_oh_man 7mo ago> 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.
- samrus 7mo agoTrue. But lego has stood the test of time. Thats way harder
- rrr_oh_man 7mo agoWhat do you mean by that?
- SteveNuts 7mo agoNot 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.
- Thorrez 7mo ago>The frequently cited "0.002mm tolerance" is misleading without context. LEGO's actual mold precision is 10 microns, but different features have different critical tolerances. The article never mentions what piece has a 0.002mm tolerance. Is there any such piece? If there's no such piece, then "0.002mm tolerance" is not just "misleading without context", it's straight up false.
- ozlikethewizard 7mo agoIs it a language mixup, ±0.001mm being called a 0.002mm tolerance? Otherwise I cant figure it out either lol.
- Karliss 7mo ago0.001mm is 1 micron not 10.
- butILoveLife 7mo agoAfter 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 sets do not have this requirement. I think Lego has a huge incentive to promote this idea that they are high quality to justify the enormous price of decades old technology.
- thowawayko1 7mo agoAfter 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.
- double0jimb0 7mo agoAgreed. Same or greater injection molding challenges for bottle caps, small plastic containers, things that also are in the hundreds of millions of parts annually. More challenging as they are often using polypropylene which is harder to mold due to its high anisotropy (shrinks in different rates depending on if it's flow or cross-flow direction).
- hypercube33 7mo agoIll admit that their parts do have higher quality than their competitors (various Chinese and other companies) making similar or compatible parts - some have injection molding blemishes or whatever on them that I've purchased from AliExpress or Walmart so in this space they are above everyone else in their space.
- adamzwasserman 7mo agoThe reason this is impressive has less to do with the tolerances themselves and more to do with backward compatibility across decades at scale. That's the genuinely hard part. The history here is deeper than most people realize. The United States spent fifty years (roughly 1800 to 1853) at the Springfield and Harper's Ferry armories trying to achieve what LEGO now does routinely: parts manufactured to tight enough tolerances that they are truly interchangeable without fitting. In 1853, a visiting British inspector randomly selected ten muskets made in ten different years, disassembled them, mixed the parts, and reassembled ten functional muskets using only a screwdriver. Tolerances of a thousandth of an inch. It was considered impossible by most of the engineering establishment of the time. The way they got there was by building machines, then using the parts those machines made to build better machines, then using those improved parts to build even better machines. A virtuous circle of transferring skill from human hands to tooling. This is the actual origin story of what historians call the American System of Manufacture, and it's the foundation the entire modern automotive supply chain sits on. So yes, any competent injection molder holds tight tolerances today. But that's precisely the point: the reason it seems unremarkable now is that two centuries of compounding precision made it so
- lqet 7mo ago> A 2x4 LEGO brick manufactured in 1958 will snap perfectly onto a brick molded this morning in Denmark, China, Hungary, Mexico, or the Czech Republic. In the late 90ies, I regularly played with my uncle's old LEGOs from the late 60ies and early 70ies. They were stored in an unheated attic for 25 years. I remember that some of the old bricks didn't "snap" at all anymore to my newer bricks. They were either extremely difficult to stack onto a new brick, or didn't have any friction left.
- scatbot 7mo agoLego 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 sets feel like display models than something you can play with. The Mindstorms/NXT line had huge potential but then just sort of fizzled out. And the push towards smartphone-dependent toys feels weird. Who actually wants their kids staring at a phone to play Lego? It's so sad, because the core product is basically perfect.
- utopiah 7mo agoNostalgia... Lego was amazing decades ago so we want it to remain so. It's not anymore though. The whole raison d'etre, namely infinitely recomposable bricks to be creative, was lost the moment they realized they were a LOT more money in custom sets. Sets become collectible, perishable, trends can form, secondary markets exists, etc. It's simply about the baseline, not the principle. Sorry.
- thinkingtoilet 7mo agoLego is still amazing and you don't have to buy expensive sets for your kids to enjoy them. My son loves Legos and if he gets a set for his birthday it doesn't last long before he takes it apart and starts building other stuff with it. This is one of those instances where it feels like people are terminally online. Or like the meme of the guy standing in the corner while everyone else is having fun at the party. You can find Legos being given away in a local buy-nothing group. It's still just as magical for kids as it ever was. These complaints are only from an adult who doesn't play with Legos. Who cares if sets become collectibles? Get other sets and have fun with Legos. These are toys that are meant to be played with. Play with them.
- Latitude7973 7mo ago*Lego
- deleted 7mo ago[deleted]
- m3kw9 7mo agoIf you buy any knock off legos, you are guaranteed 3 things, 1. Crappy instructions 2. Noticing the snap pressure is inconsistent and often too tight our bouncy. 3. Swearing at that manufacturer after every page.
- lnsru 7mo agoThe 2. is very annoying. Especially when big sets fall apart due to this issue. Let me add this: 4. no spare parts available. So when I break weird Chinese invention the whole set becomes useless without that very special part. It happened few times and I got back to used Lego sets.
- zvqcMMV6Zcr 7mo agoFor me it is 1. Terrible quality of all rubbery/soft elements. 2. If it is original model (instead of ripping of existing set), it often contains huge, shell like elements, that can't be easily be in custom designs. 3. I guess the previous point doesn't really matter, when bricks are designed to be assembled once and are impossible to pull apart without hurting your fingers.
- em-bee 7mo agonot true at all for most alternative brands (they are not knock offs, the patents are expired so they are legal, and comparable in quality), same for cloned sets (shady companies cloning lego sets using alternative bricks (the bricks are legal, the cloned sets aren't). the quality of alternative bricks is good. the quality of the instructions as well.
- iso-logi 7mo agoThey are called "Lego" not "Legos". I thought this forum was for intellectual discussion, full of intellectual people. You're a pseudo-intellectual at best.
- wek 7mo agoFor 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 :)
- brightbeige 7mo agoMakes me think there could be a big cognitive difference when playing with Lego as well, for example, divergent vs convergent thinking.
- Thlom 7mo agoYou can still buy LEGO Classic which is just a bunch of bricks.
- antonyh 7mo agoFrom 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.
- wffurr 7mo agoWhen I was a kid and I got a new set, I would build it according to the instructions, play with it, and then disassemble it and sort it into my brick collection. Occasionally I would get the instructions back out and re-build it, and other times I would kitbash and make random cool stuff. My parents still have all my Legos from the 90s, including the instructions, and I've been able to rebuild a bunch of the space ships with translucent neon accents. It's pretty sweet and my kids love it.
- beastcoast 7mo ago
- jimmar 7mo agoI've never regretted buying Legos for my kids. Yeah, the kits can be expensive, but they last forever. We've thrown out or donated lots of old toys, but the Legos will never be given away.
- Freak_NL 7mo agoIn terms of toys which my son got from my childhood, Duplo and Lego stick out. We kept everything; booklets and parts. We built the classic town square (set 1592) recently, and we've got all the parts, including the statue bits! Only the printed lettering on the sign's 1×8 white brick had faded. Sure, some puzzles and books survived, but the Lego stands out. If he ever has children they are in for a treat…
- pubby 7mo agoLego's original moat was their patent. This expired in the 80s, and so their new moat became their manufacturing tolerances. None of their competitors could match the quality of their product. This lasted until about the 2010s when clone brands in China finally caught up, and coincidentally, Lego's own quality started slipping. Thus, they needed a new moat, and the choice was obvious: licensing.
- mejutoco 7mo agoI wish Lego would find a digital equivalent as universal as the bricks for programming. I think it could be another moat for them. But it seems they keep changing it and it does not seems as simple or as universal as it could be. I am thinking more programming with blocks than using a tablet etc. to program the blocks. IMO it is a wasted opportunity.
- herpdyderp 7mo agoWhat knock off brands come even close in quality? Everything I’ve tried that isn’t name brand LEGO is hot garbage.
- operation_moose 7mo agoI've ordered 2 sets off of AliExpress (the Stargate BC303 and BC304 MOCs) and was quite impressed. No box, digital instructions, and a few minor color swapped pieces; but complete and everything went together very well.
- lich_king 7mo agoThis 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, which lets children build tall structures. > But in an assembly system like LEGO's, small errors accumulate. Stack ten bricks end-to-end and the cumulative tolerance is ten times larger. This is why LEGO models larger than 1 meter become difficult to build > The lesson isn't that everyone should match LEGO's tolerances. It's to understand what your product actually requires, then build your manufacturing system to deliver that at the scale and cost your business model demands. I know I'm tilting at windmills, but come on.
- isoprophlex 7mo agoI too hate it when my kids apply 4 kN of force to off-brand construction bricks and they turn to ABS paste. Only LEGO (R) for my spawn!
- rkangel 7mo agoI 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.
- aaron695 7mo ago[dead]
- kspacewalk2 7mo agoWe use a Lego phantom[0] to control for geometric distortions in a few of our MRI studies. The tolerances are so tight that it works really well. Especially important in multi-site studies. [0] https://en.wikipedia.org/wiki/Imaging_phantom https://en.wikipedia.org/wiki/Imaging_phantom
- khalic 7mo agoReally cool trivia, thanks for sharing :D
- rob74 7mo agoWas this written using AI? It does contain some interesting information, but the same information is repeated (with small variations) over and over again in a mind-numbing way that made me stop reading after about half of the article...
- Tossrock 7mo agoIt certainly feels that way. Some tells: "Precision, for LEGO, isn't an engineering choice, it's a brand promise." - The classic "It's not just x, it's y", just minus the "just". "One philosophy optimizes for cost, the other for perfection." - Again we see the x/y structure; AI writing often features these forms, eg comparisons (x vs y), conversions (x into y), negated emphasis (not x, but y), etc. "When you have multiple parts in an assembly, use statistical analysis for tolerance stack-up rather than worst-case math. Traceability matters. Track your defects so feedback turns precision into reliability." - More x/y followed by a short stinger ("Z matters"), and the closing sentence again follows the "x/y" pattern. For funsies I tossed the whole thing into a purported AI detector and it said 90+% confidence of AI. I don't trust those types of things very much and suspect they have high false positive rates, but I have read that AI writing generally has measurably lower entropy, so maybe it's plausible, and in this case it aligns with my existing beliefs, so it obviously must be true.
- hjkeil 7mo ago"That level of traceability makes quality assurance more like a forensic investigation than a random inspection." This was the tell for me.
- antonyh 7mo agoThis is why Lego has nothing to fear from 3D printing.
- wongarsu 7mo agoNot in terms of people printing lego bricks. But at least as an adult, designing things in Fusion and printing them scratches a similar itch as building lego. And 3d printing is now pretty accessible to the 14+ age group. I doubt this will completely replace legos, or that it's even their biggest threat, but I'd be surprised if it had no impact
- antonyh 7mo agoFramed that way yes, but wouldn't it be cool to 3D print interlocking parts that can be reassembled in different ways?
- tmaly 7mo agoIt would be interesting if 3D printers could reach this tolerance
- antonyh 7mo agoI'm sure they will if they can't already, but the price of the tech & the materials could be the limiting factor. How much would a hobbyist be willing to spend on consistent 10-micron 3D printing?
- spatular 7mo agoThe trick is to redesign the bricks for worse tolerances. With 3D printers you can print very nuanced springy elements that are impossible to achieve with injection molding. I got some reasonable bricks years ago on cheap printers with PETG, should work even better now with modern printers and ABS.
- rkangel 7mo agoThe 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".
- perfmode 7mo agoThis is the most interesting point in the thread to me. Tolerance stack-up is the reason tight per-part tolerances matter at all. A single brick being precise is table stakes for injection molding. The hard problem is what happens when you compose hundreds of them. The decoupling strategy you're describing is really similar to how you handle error accumulation in any large composed system. You can't make individual components perfect enough to avoid drift at scale, so you introduce boundaries where the accumulated error gets absorbed rather than propagated. In Lego's case that means designing joints between sections that are forgiving enough to accommodate the stack-up from each chunk independently. It's also why knockoff bricks can feel fine for small builds and then fall apart (sometimes literally) on larger ones. If your per-part tolerance is 3x worse, it doesn't matter much for a 20-piece build, but for a 2000-piece build your cumulative error budget is blown long before you're done. The failure mode isn't that any individual brick is bad, it's that the composition doesn't hold. I'd be curious whether Lego publishes or talks about those chunk size design rules anywhere. That seems like the actually interesting engineering story, more so than the per-part tolerance numbers that get repeated in every article about them.
- jjk166 7mo agoThat's actually not too difficult. So long as your process variance is centered around nominal, the stackup will tend to cancel out. You might run into trouble if your kit involves hundreds of identical pieces from the same batch being assembled together, but that's rare. For large builds from multiple kits, it's very unlikely they have the same errors.
- nmeofthestate 7mo ago"A minifigure head mold evolved from 8 cavities in 1978 to 128 cavities today." Initially I thought this meant a lego minifig head has 128 internal cavities, but finally realised it means a single mould now makes 128 heads.
- deleted 7mo ago[deleted]
- yubainu 7mo ago[flagged]
- twodave 7mo agoBoth of my boys (9 and 11) still enjoy both the sets and the classic Legos. They're constantly building trucks, trailers, etc. One even designed his own working dump-truck. They're still great toys for imaginative play, and the fact that the sets can be broken down and used in new ways just keeps the fun alive. My oldest even designed and had his grandpa build him a lego table with a removable/reversible top so he could paint different geographies for his cities and whatnot that he likes to build.
- yubainu 7mo ago[flagged]
- joering2 7mo agothere is a solution for that, its called flip-flops. But it would be hilarious if LEGO would add a pair in one of their sets :)
- lvl155 7mo agoWorth mentioning that tolerance is that low for multi-stud pieces. For an individual stud it’s closer to 0.02mm but as you add more studs tolerance spec goes up.
- solidsnack9000 7mo agoI would like to better understand the reasoning behind what the author says here: A balanced 16-cavity mold costs 3-4x more than a single-cavity mold but only produces 16x the parts, which is why they only make economic sense above 500,000 units.
- s0rce 7mo agoI guess if a single cavity mold costs $30,000 and a 16 cavity mold costs $110,000 you have an additional expense of ~$80,000, divided over half million parts is 16 cents. So lets say somewhere from 5-10cents per part to go 16x faster. My numbers might be off a bit but seems in the ballpark. I also don't know much a lego brick costs to make in terms of materials/opex.
- coryrc 7mo agoIn this context, a cavity produces one part. A cavity can only produce, lets say, 200k parts. If you produce 400k parts, you only need a single mold, but you've only used 25k wear on each cavity, but you paid more for the mold instead of only 2 of the cheaper single-cavity molds.
- SV_BubbleTime 7mo agoSomething that took me years of working with custom plastic injection part experience to notice still kind of shocks me… Legos don’t have draft. That means nothing to 99% of you, but someone else here must understand what the implications of that are for releasing from molds at a mass scale.
- jjk166 7mo agoActually they do have a draft. The bricks are designed so you don't notice it, both by the draft angle being quite small, and the parting line is moved up slightly so by the time you get to the bottom of the brick you're back to the original width. https://medium.com/@bsather/breaking-down-the-perfect-design-of-a-lego-brick-a95000bb0a7e https://medium.com/@bsather/breaking-down-the-perfect-design...
- SV_BubbleTime 7mo agoI was annoyed at this one time so I took two legos and put them under the microscope. I couldn’t see it. Which is just to say how fucking tiny the scales are here. For production parts we’re looking at drafts around 3 degrees. Which is… not what they have even considering the tuck back in!
- jjk166 7mo ago3 degrees is the generic "I don't care and don't want to worry about it" draft angle. In many cases 0.5 degrees of draft angle is a non-issue. 3 degrees on a lego brick would be a difference of .3mm over its height. For comparison an amoeba is about .5mm. If you're zoomed out enough that you can see the length, you're not going to be able to discern the angle. The only way you'd see it is to check for the gap between the wall and a precision square.
- nayuki 7mo agoUpvoted, and the English prose is pretty good in spelling and grammar, but the metric units in the writing need improvement. > 10 microns "Micron(s)" is a deprecated word since 1967 and "micrometre(s)" must be used instead. The reason is that it is a non-standard word; if "micron" is accepted, then we should also accept the nonsensical words "millin", "nanon", "kilon", etc. The metric system is supposed to be easy to learn with consistent rules and as few special cases as possible. > 4.8mm ... 0.01mm ... "0.002mm tolerance" These numbers are correct, but it's harder to quickly skim the text and make comparisons because the number of decimal places vary. It would be better to write 4.800 mm, 0.010 mm, 0.002 mm to make the reader's job easier. Or convert everything to whole micrometres, like 4800 μm, 10 μm, 2 μm. > withstand over 4,000 Newtons Almost correct, but the unit must be decapitalized to "newtons". This is similar to how other name-based units are decapitalized - like "100-watt light bulb", "12 amps", "3 gigahertz". > 2-3 Newton insertion force It must be written as "2–3 newtons". When the unit name is written out in full, it follows normal English pluralization rules (e.g. metres, seconds, volts, pascals, kelvins, ohms, teslas). The only exceptions are hertz and siemens, because they already end with -s or -z.
- jjk166 7mo agoThis is why we measure things in baby elephants per football field.
- FarmerPotato 7mo ago>A 2x4 LEGO brick manufactured in 1958 will snap perfectly onto a brick molded this morning.. This is just manifestly NOT TRUE. The outward appearance may be the same. There were intentional improvements to the walls and tubes that make fit less than perfect. Generally, today's brick requires less force to snap and un-snap, because the compression is focused onto fewer points. (I guess this lowers the "hoop strength".) Older bricks can be either: completely loose, or clutch so hard to each other they are the devil to take apart. I have many bricks from 1962 onwards. The oldest 2x4s and 2x2s were made of cellulose acetate (CA) (in North America, intermediated by Samsonite.) CA were softer, and either had less clutch power to begin with, or lost it over time. When I got them in the 70s, they fit but wouldn't reliably stick to each other, nor later 70s-80s bricks (all ABS plastic by then.) (CA bricks were mostly red, and they have a pale orange tint.) 70s-80s bricks did not always age well. Aged 1x4 or 1x8 bricks can have the outer wall bowed inward slightly. This is a mold engineering problem anyway. Later, 80s bricks were improved by slightly thinner walls and some reinforcing tabs. The older, aged bricks can stick brutally to each other and to newer bricks. The 10x10 baseplates didn't age well (these were once box-tops! Tog'l Toys also had the baseplate as a box-lid.) Possibly made of polycarbonate (PC). Other large plates in ABS-- for instance 6x16 (Auto Chassis, red) -- have warped. They were also more brittle to begin with. So inside Brick geometry has changed over the decades. 60s-70s bricks are closer to plain boxes with tubes inside - as the Kiddicraft prototype of the 50s. In the 80s, the outer walls got thinner and had tiny studs where the studs contacted the wall. And the tubes changed from cylinders to just slightly clover-leaf inside, so that a tube over a single stud now formed 4 points of contact, and came apart with lower shear force. (I believe this also made it easier to pry a plate off of a larger plate.) I have Fabuland sets from early 80s, whose plain bricks are so stiff, they are positively brutal to snap onto each other or 90s bricks. The brick geometry of today is much improved. And the ABS is more "plastic", perhaps more "B" (butadiene rubber) or less "S" (styrene): I can drill it more cleanly. Mid 80s and 90s bricks will interoperate just fine with today's. But bricks from before that period didn't age so well (and their corners, I believe, used to be harder.)
- novaleaf 7mo ago> The 66-year-old brick will have the exact same interference fit, the same clutch power, the same 4.8mm stud diameter. Pretty sure this is false. Old bricks had way higher clutch power, so high that it was deemed too difficult to separate. Sometime in the 90's the grip strength was reduced. This false claim is underpins the entire article :(
- runxel 7mo agoI concur. I had "inherited" the sets of my 10 years older brother, and they where a pain to play with. It was sometimes impossible to separate the pieces, especially if it were plates with no leverage and nothing to grip.
- tsoukase 7mo agoTo make a bunch of plastic toy bricks a multi billion company you have to produce very special ones. LEGO is a marvel of human entrepreneurship, mechanical, designing and marketing. Diverse and totally different professions should cooperate together with a lot of innovation. To make one characteristic is doable, all of them is very difficult.
- jjk166 7mo ago> They're cut from hardened steel using wire EDM, a process that erodes metal with controlled electrical sparks, achieving tolerances within a few microns. They're made by sinker EDM, not wire. The physics are similar but it's a radically different process. > But in an assembly system like LEGO's, small errors accumulate. Stack ten bricks end-to-end and the cumulative tolerance is ten times larger. That's not how these tolerances work. The super tight tolerance is the interference fit on the stud. This is a diameter. You don't stack diameters together. Each connection is independent. Where you can get tolerance stackup is brick height and stud spacing. Although even here random errors tend to cancel out as you mix lots. >LEGO's system reveals timeless truths about manufacturing. Process control beats precision machining. A stable, repeatable process produces better results than chasing the tightest possible mold tolerances. Invest in monitoring rather than just tighter specs. The whole article says the opposite. Lego relies on precision machining and tight tolerances. Process control is necessary in addition to these.
- post_break 7mo agoThe whole article makes me mad when they factually get so much wrong. Like I had to stop reading.
- donquixote25 7mo agoI could be wrong but this article reads like AI. I don't understand why its getting upvotes.
- thot_experiment 7mo agoLego is still the best toy, but man, I really miss the old style Technic sets where most of the pieces were very generic vs today's sets which are less versatile. 8480 and 8250 as examples (my two favorite sets growing up, though I didn't manage to get my hands on 8480 until I got my first job)
- iso-logi 7mo agoI collect Hot Wheels but have always found Lego to be annoying. It's a pain in the ass to put together, pain in the ass to move, pain in the ass to collection. The costs are out of this world and most collectors don't even build their sets, they keep it in the box from 20 years ago. At least with Hot Wheels you can see the car inside even when still packaged.
- thot_experiment 7mo agoYeah that's a completely different approach, I buy lego to have access to more pieces so that when I dump them all on the floor and build whatever comes to mind I have more to play with.
- mikewarot 7mo agoFor me, Legos shouldn't ever include instructions, or anything other than generic parts. The whole idea is to dream up something, then reify it. It's so fetch! When I started seeing the non-generic "build one thing" sets, with appropriately high sticker prices, Lego lost it's luster. The additional downside of ending up with special purpose pieces, just made it worse. The precision with which the blocks are made is comparable to Ford's use of Gage blocks to make perfectly interchangeable parts across the globe. It's fascinating just how many of something can be made in this manner, and how the costs just keep slowly going down as the quantity scales up.