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The First 3D-Printed Steel Bridge

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Re: The First 3D-Printed Steel Bridge

#41

Post by skookumchuck »

reneherse wrote: post #38
skookumchuck wrote: post #28

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 no…

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.

Re: The First 3D-Printed Steel Bridge

#42

Post by adkaplan »

hathawsh wrote: post #23
wheelie_boy wrote: post #15

Earlier quoted context omitted.

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

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

Re: The First 3D-Printed Steel Bridge

#43

Post by adkaplan »

matte_black wrote: post #19
delecti wrote: post #9

Earlier quoted context omitted.

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.

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

Re: The First 3D-Printed Steel Bridge

#44

Post by adkaplan »

skookumchuck wrote: post #40
jacquesm wrote: post #37

Earlier quoted context omitted.

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.

Re: The First 3D-Printed Steel Bridge

#45

Post by mdorazio »

asnyder wrote: post #32
mdorazio wrote: post #29

Earlier quoted context omitted.

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 su…

How can I contact your shop?

Shoot me an email - michael at rndx2 dot com

Re: The First 3D-Printed Steel Bridge

#46

Post by mdorazio »

jacquesm wrote: post #35
mdorazio wrote: post #30

Earlier quoted context omitted.

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 ma…

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 rea…

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/

Re: The First 3D-Printed Steel Bridge

#47

Post by Max-q »

noen wrote: post #34
opencl wrote: post #33

Earlier quoted context omitted.

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

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.

Re: The First 3D-Printed Steel Bridge

#48

Post by ofrzeta »

skookumchuck wrote: post #40
jacquesm wrote: post #37

Earlier quoted context omitted.

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.

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.

Re: The First 3D-Printed Steel Bridge

#49

Post by bkor »

mdorazio wrote: post #20
mikenew wrote: post #17

Earlier quoted context omitted.

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 m…

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 a…

> 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.

Re: The First 3D-Printed Steel Bridge

#50

Post by jacquesm »

skookumchuck wrote: post #40
jacquesm wrote: post #37

Earlier quoted context omitted.

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.

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.

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