
The First 3D-Printed Steel Bridge - odabaxok
https://gizmodo.com/the-first-3d-printed-steel-bridge-looks-like-it-broke-o-1824252512
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jstanley
I recommend the video, it includes some footage of the printing process:
[https://www.youtube.com/watch?v=STAHy6hTP14](https://www.youtube.com/watch?v=STAHy6hTP14)

Unlike traditional 3d metal printing, which works by laying down a powder
which is then baked in an oven to fully sinter it, this bridge seems to be
constructed by directly welding additional metal to the existing structure.

Here's a fun DIY attempt at the same kind of idea:
[https://www.youtube.com/watch?v=sFXniBbgbw0](https://www.youtube.com/watch?v=sFXniBbgbw0)
(and, if you're into home machining, almost all of the other videos on his
channel are very enjoyable too).

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joshu
I knew this was gonna be Tony before I even clicked.

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grownseed
Commenting on this while my 3D printer is making parts for my new 3D printer,
with parts I designed from the comfort of my own home. 3D printing and the
RepRap movement have managed to get me truly excited about something for the
first time since I took up programming 20 something years ago.

We're not quite at the fully consumer-ready stage yet, there is a lot of
tinkering and know-how that would be too much for the average consumer. I'd
say the current state of 3D printing is at the same level 2D printing was ~40
years ago (comparatively), but I'm confident we'll reach a similar stage
within the next few years.

For those interested, the RepRap community is extremely active and there are
lots of open-source projects (including hardware) to get involved with.

~~~
mikenew
Same experience for me. I bought a cheap printer from eBay and slowly started
re-designing and replacing existing parts by printing them out on the printer
itself. Nearly 100% of the printer has been replaced, and I’m finalizing the
design for a second printer. I’ve started making contributions to the
firmware, slicers, and host software to get features I want, learned to model
in Blender, learned about programming micro-controllers, started researching
thermoplastics, material science, and the list goes on.

3D printing is an incredible intersection of software, electronics, machinery,
chemistry, and an open, community-driven R&D environment. It is the most fun
I’ve had since being a child building RC cars.

~~~
mdorazio
I want to offer additional context for other people who read this and may not
be familiar with how 3D printers work. The core components of a 3D printer are
not currently printable. These components are: power supply, control board,
steppers, rails, bearings, belts, hotend, and the bed. When people talk about
printing parts for their printer, they are almost always referring to the
secondary parts like the carriage assembly, extruder gears, fan shrouds, and
frame components that can be made from a large variety of cheap materials
(acrylic, MDF, ABS, etc.). We are a _very_ long way from a printer being able
to actually replicate itself.

Source: own and operate 50 3D printers

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sterlind
How far away are we from 3D printer + CNC mill/laser cutter + robot arm for
assembly?

Incremental deposition may not yield a working 3D printer, but couldn't a
small ensemble of machines construct all their parts? (Minus the chips, for
now)

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mdorazio
Great question, and the answer is probably "it depends". I've got all of those
except the robot arm/part picker and even if you had really expensive tools
like metal sintering printers and a 5-axis CNC mill, you would still have to
buy a lot of the components that are produced with specialized machinery. I'm
going to go out on a limb and say that maybe in 20 years we'll be able to
self-replicate machinery with raw materials inputs and a lot of work. It
wouldn't be even close to economically viable to do so, but it might be
possible.

It's important to remember that the majority of the core technology in 3D
printing today actually dates back to the late 1980s. We're starting to see
some interesting developments in materials and capabilities, but there are
still plenty of limitations that need to be overcome.

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jacquesm
I highly doubt your estimate is even in the ball(bearing) park.

Spindles, motors, circuit boards with components on them and bearings, slides
and so on are all multi material or very complex processes usually only doable
if you produce a lot of something in one go.

Just try to think about what it would take to print something as trivial as
lacquered copper wire for stepper motor windings or a circuit board with a
reasonable level of integration.

And the biggest issue with that prediction is that there is no gain from it:
printing the non-commodity parts is the whole trick to efficient 3D printing,
mass produced parts will have incredible accuracy and very low pricing so use
them when you can and 3D print the remainder.

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mdorazio
I don't think you're arguing against what I actually said. I said in 20 years
it might be possible to replicate a printer using nothing but raw materials
and a lot of work, but it wouldn't make sense economically. That's very
different than saying you'll be able to print all the parts you need in one
go, or that you would want to, which obviously isn't viable without molecular-
level assembly. That's a holy grail in the distant future. But making PCBs is
already possible without specialized equipment, metal sintering gets you
pretty far on components needed for things like steppers and threaded rods,
etc. If you follow the research being done (ex. [1,2]) it's pretty clear that
the boundaries of what's currently possible are being pushed in interesting
directions.

To me the biggest hurdle is the electronics, which currently do require
special tooling to even produce basic components. You're probably right that
we're more than 20 years from self-replication ability (again, not
practicality), but I'd be surprised if it's more than 50 years out.

[1]
[https://arc.aiaa.org/doi/abs/10.2514/1.A33409](https://arc.aiaa.org/doi/abs/10.2514/1.A33409)
[2]
[https://3dprintingindustry.com/research/](https://3dprintingindustry.com/research/)

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eloff
Just beautiful. The ability of 3D printing, not just to automate a traditional
construction process, but to enable radically different designs is going to
create a whole new style of architecture. Many of the old constraints don't
apply and the human imagination is given a freer reign. There's still that
pesky law of gravity that must be respected, but otherwise this offers a
remarkable freedom.

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delecti
I suspect that the time and cost involved in non-trivial structures will limit
any real experimentation with non-traditional designs. It might be trivial to
throw away a kilogram of plastic on a failed prototype, but the same doesn't
extrapolate up to experiments with bridges.

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matte_black
You could sample the projects in VR to get a feel for them.

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adkaplan
It seems MX3D had the same thought judging from their demo video

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opencl
The article is light on technical details but they apparently converted a
normal industrial welding robot into a giant FDM machine that deposits 1-3 KG
per hour per nozzle. Really interesting. From the photos it looks like the
layers don't even have to be parallel to each other.

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skookumchuck
While an amazing new technique, I'm a bit disappointed that it was used to
create an "art" bridge. As an engineer, I'd be more interested in what a
bridge would look like if it was pure utilitarian - the only material on it is
what must be on it, not what is required by machining costs and stock material
shapes.

Before anyone scoffs that this must result in nerdy and ugly shapes, airplanes
are beautiful shapes and none of that is for aesthetics or artistic purposes.
It's simply the best shape for flying. As manufacturing techniques improve,
the airplane shapes get more subtly flowing forms, and get even more
beautiful.

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reneherse
Hard to look at the history of aircraft and think aesthetics have nothing to
do with the shapes designers choose. Aesthetics may not be the driver, but
it's definitely an input in the process, to varying degrees.

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skookumchuck
> Hard to look at the history of aircraft and think aesthetics have nothing to
> do with the shapes designers choose.

In my reading about the history of aircraft, aesthetics have nothing to do
with it. Performance and cost are everything.

For example, the elliptical wing of the Spitfire is often mentioned as a big
part of the beauty of the design. But the elliptical planform is the most
efficient wing design (the Mitsubishi Zero had one, too, for the same reason).
Giving your pilots every edge possible is _everything_ in those designs. And
yet look at the beauty that resulted.

The downside of the Spitfire shape was it took twice as many hours to produce
as the Me-109, which was designed to be easy to manufacture.

I can't think of a single successful airplane design that was designed to be
beautiful - from the Wright Flyer to the Sopwith Camel to the Spitfire to the
DC-3 to the Concorde to the Blackbird. Not one. Yet they're all beauties.

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devilshaircut
A bridge designed on purely utilitarian principles would not be 3D printed.

Art makes us think about what could be - and imagine a future of solutions
that are utilitarian in new ways, or address needs we didn't know we had.

There is beauty in engineering. There is also beauty in pure imagination.

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jacquesm
Wasn't this the first?

[https://www.tudelft.nl/en/2015/io/the-first-3d-printed-
bridg...](https://www.tudelft.nl/en/2015/io/the-first-3d-printed-bridge-in-
amsterdam-2017/)

Ah, it is the same project only a bit delayed and they've redesigned the
bridge itself and moved the project indoors during the printing phase (which
makes good sense).

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pasta
At first I was a little shocked it took 6 months to print (weld if you like).
But thinking about it, it doesn't seem that long for such a complicated
design.

Great work!

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yetihehe
It doesn't matter if it's complicated. Probably they can't do it faster
because they have to melt so much steel.

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fudged71
There was a section of this bridge on display at the Autodesk Gallery in San
Francisco. Very heavy :)

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LifeLiverTransp
Such beauty, such aery reduction to the basics...

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karmicthreat
What was the new type of steel they used?

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jstanley
I took that to mean that it is not hot-rolled steel, cold-rolled steel, cast
iron, or any other traditional method of converting a lump of iron ore into a
usable piece of steel.

It's 1000 km of welding wire welded together. It counts as a new "type" of
steel depending on how flexible you are with what counts as different "types".

~~~
karmicthreat
That is a good point though. Since its just mig wire you could change out the
wire at various points to change the properties of the steel.

~~~
jstanley
You could use a combination of stainless and mild steel to write some text on
the surface of the bridge.

The surface of the mild steel would rust and the stainless wouldn't!

