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Comment by ChuckMcM | Hacker News Reader

I'm wondering what process uses molten metal. Or if it was another process that ended up creating molten metal (like a battery fire of some sort).

Given the hydraulic fluid mention I was also speculating that a gigapress might be involved.

Like everyone commenting I am always amazed at exothermic events that can't be put out by water or CO2. The only one I've ever seen "in person" (other than the obligatory set some magnesium on fire in chemistry) was a halon dump on an IBM System 370 when the water coolant system burst a pipe and shorted the many bus bars. That one triggered a 15 second siren followed by a halon dump. I found it quite exciting, the plant manager, not so much.

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> That one triggered a 15 second siren followed by a halon dump. I found it quite exciting, the plant manager, not so much.

I am reminded of The Vax War - https://www.hactrn.net/sra/vaxen.html

Some may recall its opening (and closing) line:

> VAXen, my children, just don't belong some places.

The story involves a VAX 750, and an IBM 3090.

The passage that will get you to start shaking you head is:

> The fire alarm klaxon went off and the siren warning of imminent halon gas release was screaming. We started to panic but the data center manager shouted over the din, ``Don't worry, the halon system failed its acceptance test last week. It's disabled and nothing will happen.''

Thank you!!! Was trying to find this a week ago, but couldn't find the right set of search terms.

Is that a true story, and would that really have impacted Black Monday?

I never expected to find an anti-VAXer on HN

It's a "molten metal" machine at the Fremont factory, it contains "molten aluminum" and is used to stamp vehicle parts... so yeah, "Giga press".

https://en.wikipedia.org/wiki/Giga_Press

I'm pretty sure the machine in question is the giga press.

https://en.wikipedia.org/wiki/Giga_Press

One of the largest pressing machines in the world. I think it currently presses 1/3 of the frame of a model y but they're hoping to press an entire model Y frame eventually.

"press" is a bit of a misnomer, as it actually does die casting.

Die cast? Just like Matchbox!

Thank you for this I was trying to figure out what was being pressed exactly.

What is special about the GigaPress die casting?

Being able to make large, complex parts in seconds to high tolerances. A way cheaper way to make a car if you figure it out.

Injection apparently happens in milliseconds, which is crazy at the scale of half a car.

But you get weaker parts

Not really any more. X-rays and other process improvements have allowed modern die casting to approach hot forged properties. You don’t get grain flow as good as cold forging, but it’s pretty dang good now.

> Being able to make large, complex parts in seconds to high tolerances.

You don't get that high tolerances with casting the bigger you go. Thermal warpage needs correction, and there is only so much you can correct.

But the machine in question is used for a process much closer to injection molding than casting.

MIM is somewhat better with warpage

It's all relative, the basis for comparison is a standard automotive structure: stamped steel parts welded together.

Stamped steel is excellent on manufacturability, warpage, and speed of manufacturing included.

The industry after all spent a century working with it.

Aluminium alloys bring along own problems, but otherwise unbeatable on weight even if very weight inefficient methods are used, like casting.

It's a very complicated compromise even if economics is not involved.

Correct, this isn’t mere casting. It is die casting, with really good surface finish (which matters for strength) and good tolerances once you iteratively take warpage into account.

And a big reason they didn’t use this in the past is you’d get bubbles which reduce strength dramatically. But improvements in process tech and ability to use X-rays to do fast, non-destructive evaluation allows near-forged material properties. Better than castings of years past.

Is this intended to fix the misaligned body panels I constantly see on other Tesla models?

Largest in the world? It's 1/10th the pressure of the Mesta / Alcoa 50,000, which itself is still far from the largest...

https://en.m.wikipedia.org/wiki/Alcoa_50,000_ton_forging_pre...

largest diecast press

Apologies, I meant in the context of consumer automotive.

Tesla shills in here lol

What's the requirement for being a shill? Liking something and talking about it?

It's an injection molding machine actually, not a real forge, or a press.

> Like everyone commenting I am always amazed at exothermic events that can't be put out by water or CO2

Possibly the most extreme being chlorine triflouride, so reactive it's a better oxidiser than oxygen, as a result it can burn sand:

https://blogs.sciencemag.org/pipeline/archives/2008/02/26/sa...

Its aluminum die casting. This is the product that is produced there:

https://cdn.shopify.com/s/files/1/0173/8204/7844/articles/1_...

Not really casting, the process is more close to a metal injection molding/rheocasting.

Giga press.

> I'm wondering what process uses molten metal.

Casting

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