Foundations?

[VicParticipant @vic]

My first thought on seeing this was “how big do the foundations need to be for a machine this size?!”

**LINK**

[VicParticipant @vic]

[Ady1Participant @ady1]

We've got bigger, I don't know if SF finally did ever get their 15000 ton press

This incident actually made me a committed Brexiteer because "EU rules" conspired to kill it off (A well known steel competitor was going to complain to the EU so the deal got kyboshed)

**LINK**

Aha! they got a loan from the MOD and bought a 13,000 ton one from ebay Japan

https://www.thestar.co.uk/business/forgemasters-spends-ps120m-on-new-press-in-one-of-largest-investments-in-steelmaking-in-sheffield-3206219

 

Edited By Ady1 on 12/04/2023 16:46:06

[Ady1Participant @ady1]

After reading about them it looks like 2/3 of any machine pictured is actually beneath the floor

Like an iceberg

**LINK**

[NealebParticipant @nealeb]

Watching the "big press for Tesla" video, I noticed that he kept talking about "casting". To me, that means pouring or injecting something more-or-less fluid into a mould, letting it harden, then releasing. I appreciate that injection moulding in particular needs a lot of force to hold die components together during the injection process due to pressures involved. I had a trip recently around a local injection-moulding factory where they also make the moulds and was surprised at just how robust the moulds were for relatively small plastic crates.

However, my impression was that the "Tesla" press and manufacturing process was more akin to forging, maybe in just one big shove rather than by multiple hammer blows, and there was no sight of the kinds of things you would expect to see in a foundry for handling hot metal. Are these "castings" actually one-piece forgings, made by squashing (to use a technical term…) a suitable blank, cold, into a set of dies?

My background does not include this kind of manufacturing, but I'm interested to know how the big boys do it!

[Jeff DaymanParticipant @jeffdayman43397]

Not forging – the Gigapress process is just aluminum die casting. Very similar to injection moulding but liquid metal is injected fast and under high pressure to make the parts. Not new or novel at all, but Musk is doing his best to make it seem exotic. They are making very big presses and moulds, maybe the biggest ones ever. In my opinion making the front and rear frames or the whole frame of a car with die cast aluminum is one of the worst things that could be done. Repairability after crashes is already an issue in North America with die cast Tesla parts, corrosion on salted roads will be a huge issue, and creep over time may be a further issue. Horrible design choice. It is likely a cheap way to make a large complex component though, if the press and mould costs are amortized over many tens of thousands of cars. That remains to be seen…

[VicParticipant @vic]

All off topic again, I’m interested in the Gigapress itself in this instance, not so much who’s using it.

To answer some of the comments though:

The Idra Gigapress only started development in 2016 so relatively new.

The process itself is not new but as far as I’m aware but Tesla is the only company using the Idra Giga press for car parts like this. Apparently the two castings replace 80 steel parts that need to be individually stamped and then welded together. Aside from reducing the cost of production it also reduces weight of the vehicle improving range. It takes Tesla 10 hours to produce a BEV compared to 40 hours for Volkswagen to produce one.

I suspect other car makers will be using this machine or something very like it in the near future if they are to remain competitive.

[VicParticipant @vic]

Idra.

**LINK**

[Ady1Participant @ady1]

He's obviously smarter than most of us for these things but if I was a billionaire investor I would be looking at 3D printing as the main future for major product manufacture, especially since you can integrate CAD into it as a real time option

The bodyshell only needs to be recyclable

[JuddyParticipant @juddy]

3D printing is far too slow, the cycle time of that press will be a couple of minutes at most, to print the same thing will be days and will not produce the item anywhere near strong enough for the application.

[John Doe 2Participant @johndoe2]

It is a very interesting process. The original Tesla is apparently not that well designed in terms of the large number of panels needed to be cut and assembled together. So this could be a major saving in the long run – both for assembly time and cost.

As for crash repairs, surely parts can be cut out and new sections welded in, as they are today? Or in a bad case; just buy a whole new front casting, paint it while it is bare, then remove the old front and its components; bolt the new front onto the car, and move the components over into the new section. This would probably be comparable to what happens now, and a lot of time saved on masking up. And of course in a BEV, there are far fewer components in the 'engine' bay so it will be a pretty quick process.

Not sure why a one piece casting will be worse for corrosion than one made out of parts welded together? And does road salt attack aluminium as badly as steel?

[VicParticipant @vic]

Posted by John Doe 2 on 13/04/2023 09:46:01:

Not sure why a one piece casting will be worse for corrosion than one made out of parts welded together? And does road salt attack aluminium as badly as steel?

Indeed, there are quite a number of cast alloy parts under and in the engine bay of my car and they haven’t corroded away yet. Car is six years old and I suspect those parts will still be serviceable in another ten.

As for 3D printing plastic parts it is rather slow but one manufacturer has used it for prototyping a new concept car.

**LINK**

I think its exciting seeing new ideas in the car industry.

[duncan webster 1Participant @duncanwebster1]

Jet engines for carrier borne planes used different alloys in my day. This was because of the salt. I think they had more magnesium, but that's memory from 50 years ago. Having said that, the ally bits on Land Rovers were only a problem where they attached to steel. One or other would rot because of bimetallic corrosion. There was a brisk trade in door tops for series 1.

[duncan webster 1Participant @duncanwebster1]

And they made some of the superstructure of warships from ally, remember HMS Sheffield.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Vic on 12/04/2023 15:46:01:

My first thought on seeing this was “how big do the foundations need to be for a machine this size?!”

**LINK**

One of my civil engineering books covers foundations. The easiest answer is to dig down to bedrock, or sink piles down to bedrock and put a platform or grid on top of the piles. The platform can be well below ground level.

Where there is no satisfactory bedrock, they calculate the load on the basis that the ground is a liquid (after measuring the density at various depths) and then the structure is floated on it as if it were a ship. Lots of careful calculation needed. Yes it does go wrong, usually because the ground is stiffer on one side than the other, allowing the structure to tilt.

Even a modest skyscraper is heavier than an 18000 ton press.

Dave

[VicParticipant @vic]

I’d love to see one of these things being installed. Perhaps if they become more commonplace someone will actually film an installation. I’d certainly like to see a documentary on the design, construction, installation and operation of one of these machines.

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