Monday, February 16, 2015

Apple #702: 3D Printing

The university where I work recently acquired two 3D printers, and they sent out a call to any students or faculty to submit requests for objects to be printed on it, for free.  This deal was supposed to last for 2 months, and they've already had over 500 requests, more than they can fulfill in the 2 months.

When I first saw the notice go out, I thought I'd like to submit a request, and I thought I'd pick something really hard, but also something I actually wanted.  Like a piano.  I thought that would really knock them for a loop.  But then I found out that people have already made pianos with this 3D printing technology.  Incredible stuff.

I don't really understand the whole 3D printing thing, so I'm going to try to find out how it works.  I'm sure I will miss the nuances of the technology, but I'll try to give you (and me) a basic overview, a starting point.  Off I go to do my research. . . .

This dress was printed using 3D technology. It is made of links of material that interlock together on tiny hinges. The pieces can be custom-assembled so the dress fits anybody. MoMA thought the idea was so cool, they bought the technology immediately.
(Photo from ecouterre)

3D Printing is Rapid Prototyping

  • 3D printing has actually been in use since the 1980s.  1984, or 1986 or thereabouts.  But it wasn't something the general public knew about; it was a technique manufacturers used, and they called it "rapid prototyping."  You might have heard this phrase before without really knowing what it means.  I know I did. 
  • Rapid prototyping/3D printing allowed manufacturers to create a model of a part or some specialty piece that they weren't sure how it would work and test it out.  They could make one of these things, without having to go through a huge assembly line and make a ton of them, so they could customize whatever part and try out, without a lot of overhead.  This is the "prototype" part.  And, since they were only making one, it could be done quickly -- the "rapid" part.  It's not part of the name, but this one-off method was also a whole lot cheaper than making a batch of parts they weren't sure would work or not.
  • So manufacturers leaned a lot from the parts they made using rapid prototyping -- what we now call 3D printing.

In the past, this is how rapid prototyping was mainly used: to create customized, detailed parts, pretty much on a one-off basis. These bits and pieces are used on airplanes.
(Image from IFExpress)

  • An additional benefit is that it builds a product in a completely different way than old manufacturing techniques.  The older methods would basically take a big sheet of metal or plastic and punch holes into it or cut details out from it.  3D printing uses  a computer to build a custom shape out of the materials and pile the materials on top of each other. Think of a chain link fence, for example.  That has to get made as wire, which is then cut and bent and molded into shape. With 3D printing, you could basically build a chain link fence from the bottom up, not from bits of wire folded together, but from layers that are fused to form one solid object that is your fence.
  • In the past couple of years, this technology is getting used for more and more things -- everything from space station parts to prosthetics. As it's becoming more commonly used, we general-public, non-manufacturer people are starting to hear about it.  Since the technology is used not just for manufacturing test parts, but for entire objects, "rapid prototyping" isn't really an accurate phrase anymore.  It's much broader than that.  So people are now calling it 3D printing.

Now, 3D printing is being used not just to make test parts for vehicles, but to make entire chassis components, functional elements in the engine or drive train, and even to make the entire vehicle.  I'm not sure if this company made this entire motorcycle using 3D printing, but I think they made at least most of the parts with it.
(Image from CRP Technology)

The CAD Part

  • But, OK, you want to know, how the heck does it work?
  • In brief, it is lasers or some other really hot technology that zaps little bits of plastic to fuse them together according to a computer-programmed plan, and what you wind up with is a three-dimensional plastic object. 
  • Because the technology relies on a computer to tell it what to do, you first need a program.  Or a plan.  This you get from CAD (Computer-Aided Design).  Using CAD, you make a computer-rendered three-dimensional representation of the object you want to create.  This is the blueprint for your object of choice.
  • It used to be, to make a CAD drawing, you needed to buy really expensive CAD software. Not these days, and not for 3D printing.  There are lots of places online where you can design your own 3D objects to be 3D printed -- for free.  TinkerCAD is one of those places.
  • Here are some examples of people's CAD designs:

CAD drawing of a Mayan pyramid
(Image and plan by Ally Zhao on TinkerCAD

CAD drawing of Santa Claus
(Image and plan by Ally Zhao on TinkerCAD)  

The Notre Dame in Paris
(Image and plan by Ally Zhao on TinkerCAD)  

A Lego brick
(By TheFireBlast1 on TinkerCAD

A GoPro mount
(by dodgrr on TinkerCAD)

  • Starting to see the possibilities?
  • On a lot of these sites, not only can you make your own CAD design, but for those of us who are less 3D-minded, you can also download designs that other people have already made.  Sometimes there's a fee, but usually, you can download the design for free.
  • The next thing to do is send your CAD design to a 3D printer.  There are some 3D printers available for you to buy at home, but based on the little I've read, they're still pretty limited and small, and if you want to make something substantial like a piano or a guitar or a saxophone, you're better off having an industrial-sized machine print it for you.
  • How do you find a 3D printer that will take your CAD design?  Well, TinkerCAD will also 3D print your design for you -- for a fee, of course.  But there are many other places that offer 3D printing, including:
    • UPS stores -- when they first rolled out their 3D printing services in 2013, it was only for small businesses, start-up companies, and retail businesses near San Diego. They've now expanded to over 100 locations.  You'll want to find out if your location will serve anybody, or if you have to be a business to use the service.  It could be cost-prohibitive for individuals.
    • Shapeways -- seems to specialize in small objects like gadgets, jewelry, toys, and, yes, My Little Ponys

This Kosmoceratops will set you back $120 to have it 3D printed with rose gold plating.
(Design by David Krentz on Shapeways)

    • i.materialize -- lets you upload your designs, but also has a team of designers on hand who make and post new designs regularly, so there are often new products to choose from.

The egg man is a little ceramic orange guy who holds your egg for you. This will set you back $23.11 + tax.
(Design by Bert De Niel on i.materialize

    • Sculpteo -- they don't have a lot of designs to start with, but mainly support you and your designs that you can upload to their site, get a quote, and ask them to print them for you.  They will even tell you if there's something wrong with your file, and fix the problem for you.
  • These are only a few of the many 3D printing services out there.  To find a 3D printing service near you, check out 3D Hubs

The Printing Part

    • How does the printing actually work?  This is where things get more technical.
    • Basically, a 3D printer makes layers on top of layers of plastic that get fused together so you wind up with a solid plastic object at the end of it.  That's why this is sometimes called additive manufacturing, because it's adding one layer on top of another.
    • That is a very simplified explanation.  For more details, read on.
    • There are several different methods of achieving a 3D-printed object.
      • Selective Laser Sintering -- the key word here is laser.  This type of 3D printing uses a laser, beamed at a heap of powder, which can be made of plastic, or ceramic, or glass, or metal.  The laser, following the CAD instructions, zaps the powder to create a thin, solid layer of the object. Then it spreads another thin layer of powder on top of the first layer and, again, according to the CAD instructions, zaps that to melt the powder into another layer.  Repeat until the object is complete.  This method seems to be the most commonly used.  You can see how the process works in the video below.

    Video of selective laser sintering starts at about 3:20. Includes lots of interesting description of how the product is cleaned up and painted as well.

      • Fused deposition modeling -- picture a glue gun, but one that melts plastic instead of glue.  This uses a filament (long thin strand, like a wire) of plastic or metal, which is fed into a nozzle that heats the plastic or metal, and can be directed either by hand or by computer.  Industrial versions of this method layer the extruded lines of plastic or metal one on top of the other to create a solid object.

    This guy is trying out a 3D printing pen for the first time. The pen uses fused deposition modeling.  He has trouble getting it to do what he wants, but I think it's because he's not layering the plastic, he's drawing individual lines with it like you would do with a pen.

    This video gives you a better sense of how fused deposition modeling works on a more industrial scale. The music is super-over-dramatic, and the camera gets out of focus a lot, but you get a good sense of how the machine puts down the layers. Unfortunately, his knife can't really cut paper, but that's probably due to the design, more than the technology.

      • Stereolithography -- this method also uses a laser, but instead of zapping powder, it zaps liquid.  The liquid is a special polymer that will change in response to light -- in this case, it will harden when zapped with a laser.  A polymer can be lots of things (rubber, silicone, PVC, nylon, even silk or wool), but I think the special liquid polymers they use here are mainly plastics.

    A rather old-school animation showing how stereolithography works. I suspect this method is not one that has found its way to more customer-facing applications but is rather still used mainly by large industrial concerns. i.materialize has a ginormous stereolithography printer, but they use it to print entire batches of an object all at once.

    • There are a couple of other methods, but they are mainly variations on those 3.  I'm sure as use of this technology expands, engineers will develop still more techniques and refinements.
    • Now you know the basics of how 3D printing works.

    More Applications

    I didn't start to get excited about this until I saw some of the things you could make with it.  And I think seeing these 3D-printed objects helps you get another sense of how it all works.  So here are some more applications for you to noodle over.

    Video of 2 guys from Fender talking about how they're using 3D printing, and how they hope it can help them to uncover new tones and sounds. They're also playing some of their 3D-printed guitars. Pretty cool.

    The guy who made the guitar with stars in the body also made a saxophone. This is his first crack at it, so the results are imperfect. But I'd say it's pretty good for a first try. He says it's made of nylon, and it weighs about 1/4 of what a typical saxophone weighs.

    I seem to be especially interested in musical instruments, but there are all sorts of other applications. Prosthetics is one area that's seeing a lot of 3D printing. Prosthetic limbs need to be highly customized to each person in order to fit correctly, and it's much easier to achieve that customization with 3D printing than with conventional manufacturing methods.

    Prosthetic leg exoskeleton, being shown how the pieces fit together, made of titanium powder fused a laser sintering printer.
    (Image from Gizmag)

    This prosthetic hand combines robotics and 3D printing to make a lightweight plastic hand that is flexible, durable, and customizable. The video mainly discusses the robotics, but you can see how it was 3D printed. It looks like the 3D printing method used is fused deposition modeling. The video turns into a fundraising message, but you can quit watching at that point because the fundraising campaign has ended.

    These two guys just ate 3D-printed food. They can't get over it. The 3D food printer is loaded, not with plastics, but with edible ingredients. It takes some attention to detail, not because of the intricate shapes it can produce, but because different ingredients have different textures, consistencies, and temperatures. But ever since NASA 3D-printed a pizza, lots of companies have started taking a whack at this.  Sources say to expect 3D food printers available for purchase by the end of 2015.

    Here's the 3D pizza printer at work. There's no sound in this video.  But you can see how the crust is layered, then the sauce, then the cheese. The result is a bit sloppy, but apparently the whole thing is cooked in the process of being printed.

    There are also people who are making 3D-printed guns and knives and other weapons that have varying degrees of efficacy. 

    But I would rather end with Derby the dog, who got a pair of prosthetic paws.

    Ohio State's offer of free 3-D builds big following, The Columbus Dispatch, February 15, 2015
    3D, What is 3D printing?
    3D Printer, What is 3D Printing? An Overview.
    3D printed Exo-Prosthetic leg designed to be affordable - and beautiful, Gizmag, December 22, 2014
    "Foodini" machine lets you print edible burgers, pizza, chocolate, CNN, December 31, 2014

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