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The First 3D-Printed Steel Bridge (gizmodo.com)
131 points by odabaxok on April 3, 2018 | hide | past | favorite | 51 comments



I recommend the video, it includes some footage of the printing process: 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 (and, if you're into home machining, almost all of the other videos on his channel are very enjoyable too).


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


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.


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.


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


> Source: own and operate 50 3D printers

Someone questioning your use for operating 50 printers reminded me about a recent raid on a Dutch drugs crime organization. They used 3D printers to custom print fake Nintendo game cases, ink cartridges and fake make-up compacts and then used those to hide the drugs.

https://www.forbes.com/sites/riverbed/2018/03/14/connecting-...

To be clear, not suggesting in any way that you do this.


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)


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.


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.


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 [2] https://3dprintingindustry.com/research/


If you operate 50 printers you're presumably doing some sort of business. Nobody operates 50 printers for a laugh.

It sounds interesting. Are you printing arbitrary parts that other people send you, printing parts of your own design for your own products, or something else?


Yes to all of those. It's a micro manufacturing shop (we also have laser cutters, a CNC mill, woodworking equipment, casting materials, etc.). We mostly sell products that we design and build on Etsy & Amazon, but also do small batch runs for people who need 50+ pieces of something and the economics of injection molding don't make sense. It actually started as a makerspace, but the economics of that model were not sustainable, so we scaled into small-run product manufacturing.


How can I contact your shop?


Shoot me an email - michael at rndx2 dot com


Things I learned from RC cars as a kid:

    1. Basic electricity
    2. PWM
    3. Battery chemistry and care
    4. Transmissions/gear ratios
    5. How DC motors work. Winds and turns and brushes, etc.
    6. Suspension basics
    7. Basic RF (crystals and channels and avoiding interference)
    8. Soldering
And all sorts of hard-to-list mechanics and know-how.

I didn't realize it at the time (and I don't think my parents did, either), but I learned so much more from that hobby than I did in school, for those areas.

3D printing feels the same way. I only recently got the Monoprice 120mm^2 unit, and it's working great for what I've thrown at it so far.

What are you using for all the non-plastic parts? Do you print slides and bracing as well?


The board is an MKS Sbase 1.2 with an ARM chip running Snoothie, and I’m using the integrated stepper drivers. I switched from using the typical Arduino Mega + Ramps setup because working with Marlin was really difficult, and it felt like they were fighting a losing battle trying to cram more features into an 8 bit architecture. The motors are varying sizes of Nema 17s, but I don’t remember the manufacturer.

I have started experimenting with printed linear rails, and likely V2 of the printer will have printed rails on the z axis. The bushings are printed nylon that thread directly into the bed, x carriage, etc. I would also like to start experimenting with printed wiring, but most conductive filament is more like resistor wire, so that would take some figuring out.

As far as the frame and all that; yes it’s all printed. You’d be surprised how much the part count starts to fall when you no longer have to attach different parts together and you instead start integrating them into a single, printed part.


Agreed. One of the reasons I've enjoyed robotics so much is that it presses on all three of mechanics, software, and electronics. Since there is rarely someone who is good enough at all three it gets a huge boost by community involvement by folks with complementary skill sets. The problem with robotics was that once you did the basics, obstacle avoidance, line following, balancing perhaps. You Were sort of stuck on the next thing to work on. But 3D printers are robots that can make more interesting things so they are useful in their own right.

My current favorite application is to make holding fixtures for things like breakout boards so that I can fabricate systems out of a bunch of separate boards easily.


I'm also really excited that SLA prices have absolutely plummeted in the last year or so as well. The level of quality you can get from a ~$500 machine now is stunning, but of course it comes with its own set of problems so it's not going to dethrone FDM anytime soon. I hope we get more open-source SLA development soon though.


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.


An interesting thing that's happening alongside 3d printing is the emergence of visual programming languages specialized for geometry, the most popular being Grasshopper.


Is it really the most popular? It's a plugin for a $1000 CAD program which seems to dramatically limit who can use it.


Yes, it has by far the largest user community.

If you do a google image search for 'grasshopper geometry' or 'grasshopper architecture', you'll see a lot of buildings designed with grasshopper, including many which have been constructed.

There are other interesting things going on, like automated construction with robots or laser cutters. For example, theverymany builds massive organic structures out of laser-cut metal pieces, and the living (new york) did some interesting things with robotic placement of bricks.

New design tools specialized for automated manufacturing methods.


Rhino is the cheapest professional CAD tool on the market by an immense margin.

Compared to Solidworks, Inventor, Studio Tools, Catia or any other package, a grand is a steal.

And compared to the horrific productivity of "free" cad packages, you will quickly recoup that cost. (aka Fusion360/TinkerCAD , SCAD)


Do you find Fusion 360 productivity horrific?

I haven't used the expensive programs, but do a lot of work in 360. Would love to know what I'm missing.


Is there a way to get it to work under Linux?


This is the first time I've heard of Grasshopper. Are you referring to this?

http://www.grasshopper3d.com/

How would you recommend a 3D printer operator could learn more about Grasshopper? Are the tutorials good?


Check out the grasshopper primer. I haven't read it in a while but I used to claim it was written by programmers for non-programmers. Great getting-started guide. Rhino probably still has a demo available, too. Dynamobim.org is another option if you want to try visual programming without an investment. Dynamo is mostly visible for it's connections to other software, e.g., Revit, but can stand alone as in sandbox mode.

EDIT:Yes, it's that grasshopper https://www.rhino3d.com/6/new/grasshopper for a demo reel


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.


But that's just the thing, you aren't limited so much by time and cost. The time is proportional to the size of what you're printing, and the cost to the amount of materials and time involved. None of which says much about what the design must look like. You design it on the computer, look at in 3D on the screen as much as you like, and print a scaled model, if you must.

You don't need to print up a full-scale prototype anymore than you would do that with a traditional design and construction technique.


I assume the printing of this bridge didn't go smoothly in one pass, but one advantage of larger-scale metal printing is if something goes wrong you can grind off the failure, reposition the print head (extruder? welder???), and try again.

I suppose you could do that with FDM as well, but the precision required for smaller prints is much greater.


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


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


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.


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.


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.


> 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.


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.


I actually think that the organic look shows off the fact that it was 3D printed in a very original way. If it ended up being a utilitarian 'boring' construction then there would be no point in 3D printing it in the first place. But there is no other way that I'm aware of short of a huge cast (and that's a big if given the hollow spaces) to make this bridge in any other way.


> If it ended up being a utilitarian 'boring' construction then there would be no point in 3D printing it in the first place.

There's a great deal of point to it - saving money in material and fabrication costs.


Something like https://www.youtube.com/watch?v=CtYRfMzmWFU could be a happy medium. Shapes that must be 3d printed but forms that are less fluff and more function.


This is pioneering work, saving money in material and fabrication costs is something that will happen in the longer term when the tech is more mature.

This is a technology demonstration, not an example of super high efficiency. It also took much longer to make than it would have taken to make it in a more traditional way.

That said it still came in rather competitive compared to the alternatives, which says quite a bit about how manufacturers of such structures normally charge.


Having a welding robot run for 6 months straight will hardly reduce fabrication costs. Given the price of MIG welding wire it's also dubious if you could reduce material costs.


Wasn't this the first?

https://www.tudelft.nl/en/2015/io/the-first-3d-printed-bridg...

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).


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!


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


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


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


What was the new type of steel they used?


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".


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.


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!




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