> > > Missing Lego parts.

> Would they be able to stand up to daily use for years by enthusiastic children?

They wouldn't need to if you could just print replacements.

The real problem with 3D printing lego bricks is that I don't think any current 3D printers can print precise enough parts. Even most Lego competitors produce inferior quality pieces with less precision.

> Lego parts also fit pretty well into the "just go buy some more" approach, too. You can get a bucket of 600 Lego bricks for $30.

You'd think so. But now try to source specific parts. specific mini figures etc.. People make a living buying Lego sets to separate the sets and sell rare mini figures and pieces individually, and sell of the basic pieces in larger lots

Many pieces are only available in a handful of sets. Many pieces only exist in discontinued sets. Many pieces only exist in specific colors.

Go to a Lego store, and you will find that the more "advanced" parts are rarely on offer in anything but big sets, while the basic parts can be bought by the bucketful.

Even with the second hand market, if you're trying to reproduce something, and realise you're missing a specific part and the alternative is going to the shops and buying a set that may have the piece, or waiting a few days, being able to just start an app and pick one from a catalogue would be amazing.

There's also a market for custom minifigs, that are today often quite expensive because the people making them rarely have any options for mass production. Whole new categories both of minifigs and pieces would become possible if they could be 3D printed.

> Presumably if lots of people wanted these things, somebody would be making them at scale in China already, no? It's fine if you want them, more power to you, but they don't really seem like something the mass market is breathlessly waiting for.

There's a lot of potential for things that are impractical to mass produce because while people may agree they want the category of product, they may disagree about specific features sufficiently that the only commercially available alternatives are not that satisfactory.

And there are a lot of things that would be convenient to have at some point or other, but that is too much effort to be worth tracking down, but would be nice if you could just download and print a design in minutes.

> Kids don't want a toy that kinda looks like Groot from Guardians of the Galaxy, they want an Official Groot™ Action Figure By Hasbro like the one they've been saturation-bombed with TV advertising for.

Do you have a kid? I can for sure say that while my son certainly do want the exact specific versions of a lot of things, he also often picks up on things that are not branded, or the exact specific thing he want is not the professional, polished version. And I think TV will be losing it's hold: My son just now (and this is a regular occurrence) picked an amateur Youtube video over Cartoon Network. His favourite "show" is a Youtube channel hosted by a 6-7 year old kid that builds lego and plays video games.

(and for the purposes of this: LEGO has surpassed Hasbro as the top toy manufacturer in the world - that should say something about opportunities in this market)

> Will most people want to spend time finding out when they can get a set of five Tupperware containers for $30?

Quite possibly not. But that is a problem today because it is new. It will quickly cease to be a problem.