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Posted by scrlk 9 hours ago

Lego's 0.002mm specification and its implications for manufacturing (2025)(www.thewave.engineer)
320 points | 272 commentspage 3
Normal_gaussian 9 hours 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.

doubled112 9 hours ago||
I 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 8 hours ago||
When 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 8 hours ago||
The 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 7 hours ago||
They 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 7 hours ago||
Star 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 5 hours ago||
Very 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 8 hours ago|||
Having 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-...

jjk166 1 hour ago|||
> It wasn't until a few years ago I learned there's an official brick separator tool

You mean a little brother?

bombcar 3 hours ago|||
There are multiple brick separators, with different strengths and weaknesses.
intrasight 9 hours ago||
The tolerance is definitely more applicable to the getting them apart then putting them together.
exabrial 8 hours ago||
Backwards compatibility is something lost today. Incredible they've kept it this long.
jimmar 8 hours ago||
I'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 1 hour ago|
In 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…

yubainu 6 hours ago||
Rather than worrying about accuracy, please do something about the pain that will make you cry if you step on it!
joering2 6 hours ago|
there 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 :)
jlv2 4 hours ago|||
https://www.lego.com/en-us/product/brick-clog-5010203

Pricing is on-par for LEGO.

jjk166 2 hours ago|||
Make 'em sick, sell the cure
antonyh 8 hours ago||
This is why Lego has nothing to fear from 3D printing.
wongarsu 8 hours ago||
Not 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 7 hours ago||
Framed that way yes, but wouldn't it be cool to 3D print interlocking parts that can be reassembled in different ways?
spatular 4 hours ago|||
The 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.
tmaly 8 hours ago||
It would be interesting if 3D printers could reach this tolerance
antonyh 7 hours ago||
I'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?
SV_BubbleTime 5 hours ago||
Something 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 1 hour ago|
Actually 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...

SV_BubbleTime 39 minutes ago||
I 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!

lvl155 6 hours ago||
Worth 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.
m3kw9 9 hours ago||
If 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.
em-bee 7 hours ago||
not 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.
zvqcMMV6Zcr 8 hours ago|||
For 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.
lnsru 8 hours ago||
The 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.