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2 minutes ago, mikegarrison said:

How do you think "rolls of metal" are made?

Im confused. Why are you talking about it not being appropriate for certain metals if this is how the rolls are made. So the rolls SpaceX use are made by extrusion?

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27 minutes ago, StrandedonEarth said:

Now, if they could build a press to start stamping out bulkheads and nose parts, that would be another use for extra-wide rolls.

You could probably make tanks with 3 seams instead of dozens \o/

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16 minutes ago, Dale Christopher said:

Im confused. Why are you talking about it not being appropriate for certain metals if this is how the rolls are made. So the rolls SpaceX use are made by extrusion?

Some shapes are a lot easier to extrude than others. Sometimes the metal needs to be hot; sometimes it needs to be cold.

All I said was, "you're talking about extrusion" and that just because you can extrude a water pipe or an aluminum gutter or such (or a flat rolled sheet) does not necessarily mean you can extrude a rocket fuselage. Maybe you can; maybe you can't. I would assume SpaceX has materials engineers who know whether this is practical for their application or not.

Also, sometimes what you *can* do isn't economically what you *should* do.

Edited by mikegarrison
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17 minutes ago, Dale Christopher said:

You could probably make tanks with 3 seams instead of dozens \o/

I think Musk has said this is sort of what they want to do, long term. Roll of steel as wide as the circumference of the rocket, unroll/flatten it to the length of the rocket, then curl it the other way into a big tube with a single weld down the side, add bulkheads. He has specifically said that they’ll be using fewer and fewer ring sections as they move towards this. It would be a pretty significant piece of tooling but not unreachable. 

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4 hours ago, StrandedonEarth said:

Tooling, no, but if they had to build a new smelter/foundry to feed such large tooling, I would expect that to run 8-9 digits. And the basic 9m diameter, stainless steel barrel design hasn't changed since it changed to steel. Although by the time they want to make such wide rolls, they may as well run the steel straight from the rollers to the tube-former and skip the hassle of forming and transporting extremely long rolls of stainless steel sheet.

It might make sense once they have a finalized design to start cranking out Starship and SH boosters, although the tooling to form tubes that large would also be an expensive challenge.

Now, if they could build a press to start stamping out bulkheads and nose parts, that would be another use for extra-wide rolls.

I feel like prototyping a giant 3D printing machine may be a good idea.

Edited by Xd the great
Stupid typo
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17 minutes ago, Xd the great said:

I feel like for prototyping a giant 3D printing machine may be a good idea.

Yer but the rocket would need to be made of inconel or titanium etc... because a 3D printer can’t print steel as far as I’m aware. (Not with the same properties as conventionally made steel anyway.)

I agree tho! A 3D printed rocket would be insanely cool! No seams!!!

Edited by Guest
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16 minutes ago, Xd the great said:

I feel like for prototyping a giant 3D printing machine may be a good idea.

 

Just now, Dale Christopher said:

Yer but the rocket would need to be made of inconel or titanium etc... because a 3D printer can’t print steel as far as I’m aware

Hmm, yes, not to mention cold-rolled steel is work-hardened, which makes it tougher. Can't get that with a 3d print

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4 minutes ago, AngrybobH said:

What I know (which is not a whole lot) about additive manufacturing is it is essentially all seams.

D:

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1 minute ago, Dale Christopher said:

D:

They're right, all seams. Typically a print is built up using many thin layers, and each of those hundreds of layers is a plane that may fail structurally. Now, there are a few types of printing that make a continuous structure, but they are resin-based and unsuited for making rockets.

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14 minutes ago, cubinator said:

They're right, all seams. Typically a print is built up using many thin layers, and each of those hundreds of layers is a plane that may fail structurally. Now, there are a few types of printing that make a continuous structure, but they are resin-based and unsuited for making rockets.

A lot of modern rocket engines and parts are 3D printed, Safe to say you can do it without the whole thing being full of weaknesses since rocket engines basically contain a continuous explosion for extended periods of time.

(possibly not a good fit to replace thin sheets of metal tho I guess.)

Edited by Guest
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6 hours ago, tater said:
  Reveal hidden contents

 

  Reveal hidden contents

 

 

A couple tank construction vids.

 

So they did decide to use that nose cone for SN2 after all. It's pretty amazing how quickly they are built.

Edited by Wjolcz
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4 hours ago, Wjolcz said:

So they did decide to use that nose cone for SN2 after all. It's pretty amazing how quickly they are built.

There's a question mark-- I think these diagrams just try to show speculation as well, even if it's contested. Though it's kind of odd that the header tank isn't filled in...

 

Also, as for construction, I would assume a single, very tall ring per tank would be best to minimize welds, but it might not actually make as much sense as it seems- first, it makes it a lot harder to transport the larger sheets of metal. You need a larger, custom machine to roll them up. I don't know about this, but I could see how thermal expansion could be a problem, too, or at least harder to predict.

And, lastly, it doesn't get rid of any of the welds that have actually failed so far. Those are where the domes are attached. So it doesn't really solve the problem. I think they just need better, higher quality, smooth, automated welds protected from wind.

Edited by ThatGuyWithALongUsername
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Regarding SN1 RUD-ing, I'd prefer they blow up a few Starships on the ground than have one destroyed in flight. It's like the trial-and-error process of designing your first rocket in KSP, except 'Revert to Vehicle Assembly' takes a little longer. (Of course, this isn't trial and error, but you get the picture).

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1 hour ago, RealKerbal3x said:

Regarding SN1 RUD-ing, I'd prefer they blow up a few Starships on the ground than have one destroyed in flight. It's like the trial-and-error process of designing your first rocket in KSP, except 'Revert to Vehicle Assembly' takes a little longer. (Of course, this isn't trial and error, but you get the picture).

It took me some googling to determine that the previously explody (possibly just "collapsed") "first Starship" was "Mrk 1" and this "SN 1" was a different Starship.

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Spoiler

And does anyone remember the jokes about "Starship N-1" and its fate?

Welcome the SN-1

It's a magic of the name!

 

Spoiler

  

9 minutes ago, sh1pman said:

So what happened to Mk.2?

Being enforced by duct tape wrapping.

 

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21 minutes ago, sh1pman said:

So what happened to Mk.2?

I actually visited it a few days ago. It's still sitting there. There is work going on at the site, but not on Mk2 and not visibly on any other Starship. IIRC someone took a pic of what looked to be Octograbber 2.0 and they are moving some equipment to the Texas site.

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20 hours ago, tater said:

The video I saw (think I posted way up thread) was for steel.

 

Well, to be perfectly honest, there are more types of steel than you can poke a stick at, each with different properties. Unfortunately, the type that SpaceX uses in stainless (of which there are also countless types), which is trickier to machine and weld than your run of the mill carbon steel. Of course, automating the production process leads to uniformity and more consistent final product, and it is easier to fine tune the process. It does take time, skill and knowledge to nail it, though. I'm sure SpaceX has the money to find someone with skill and knowledge, so it's jut the matter of time.

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