[weli]

> It shouldn't be hard to print pieces that can snap together

I have some news for you. Lego piece tolerance is nuts. I think it is down to 2 micrometers. You can't achieve that in consumer 3d printers.

Now, you can make something that kinda works like lego but it wont have the structural integrity for advanced builds.

[bitexploder]

This. Even resin printers only get you kind of in the neighborhood of tolerance. Lego primarily uses injection molding for their parts. Their molds are insanely tight and low tolerance. One of the key costs of Lego bricks is the lifecycle of the molds. They don't last forever and lose tolerance over the course of several hundred thousand injections. Managing these molds and the sheer variety of parts they produce borders on logistical insanity. It is one of the most impressive logistics operations on the planet. I can build a functional car with fewer discrete pieces than large modern lego sets.

[rc5150]

Not only tolerance, but also the fact that fused deposition is just not as accurate/dense/strong as injection molding when it comes to the building-blocks application.

disclaimer: i'm not a materials scientist, just a tinkerer who 3D prints and wishes they had the capability to do injection molding.

[fsloth]

What you _can_ do is add slots for magnets. You can totally make "snap on" toys like this but it's a different concept.

[stravant]

You can easily print bricks that work. They will just require more force to assemble than normal because you have to make them slightly undersized to make up for the lower tolerance.

Just think of how many 3d prints you've seen that consist of multiple parts friction for together.

[embedding-shape]

> Just think of how many 3d prints you've seen that consist of multiple parts friction for together.

I've seen probably 10s, ranging from amateur-who-just-unpacked-their-printer to acquaintance who runs a business doing 3D printed products, and none of them come close to the experience of lego bricks, so far I'm not sure I'd actually call it "work". Stack 10 of these "custom" lego bricks and place them next to another stack of 10, and they almost certainly won't be as aligned as proper lego bricks, not to mention the whole thing will fall apart a lot easier.

[Someone]

Also: try taking them apart a hundred times and sticking them together again. If the parts initially stuck together strongly, chances are one of the parts will break down.