The First 3D-Printed Steel Bridge (opens in new tab)

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

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?

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.

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

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?

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.

> 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.

> 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.

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.