22 Dec 2019

Prof Olaf Diegel surveys the current and future state of 3D printing

From Smart Talk, 4:06 pm on 22 December 2019
Prof.Olaf Diegel

Prof.Olaf Diegel Photo: RNZ / Paul Bushnell

Edited highlights of the talk:

Olaf Diegel:

I'm going to be talking about the world of 3D printing and really what it's being used for today. Let's say for example, I wanted to make a bust of my head, I'd start it with a block of marble, a hammer, chisel and chip away all the marble. I'd remove the stone that I don't want to be left with. So that's still the way most things are made today. But in 3D printing, you start with nothing - just your virtual computer model. You send it to the printer. The printer slices it up into thin slices and then layer upon layer upon layer upon layer, it builds it up.

Olaf Diegel:

So think about it from a sustainability point of view. With the old way of subtractive manufacturing, you're cutting away material, and all of that material now has to be recycled or thrown away. In fact, commonly it's thrown away because it's too expensive to recycle. In additive manufacturing, you're typically only printing with the material you need so there's relatively little waste material. It's going to get better and in the future, it's going to become a really good way of manufacturing things.

Having said that, we've got to be really careful. I don't think 3D printing will ever replace conventional manufacturing entirely. It's going to be used for high-value, low-volume products, even in the fairly distant future. The reason for that is that it's a relatively slow and expensive technology. So you've got to be able to use it for the right reasons. It has to add value to what you're doing. And one of the best known areas where 3D printing adds value is with what's called complexity for free. What we mean by that is with conventional manufacturing, the more geometrically complex part is, the harder and more expensive it is to manufacture. And at some point, it just becomes impossible. However, with 3D printing, it's the other way around. The more complex the part, the better it is to manufacture. And I'll give you a very simple example.

Prof Olaf Diegel and one of his 3D printed guitars

Prof Olaf Diegel and one of his 3D printed guitars Photo: RNZ / Paul Bushnell

Olaf Diegel:

One of my hobbies is making guitars. So this is a guitar with a model of New York City inside the body of the guitar. We've got the Brooklyn Bridge, the Yankee Stadium, Fifth Avenue with little cars inside. Now something like that. This guitar is a Gibson Les Paul shape. I could technically print a standard Gibson, Les Paul, but it would be a stupid thing to print, as it will be really expensive, not all that good a quality, and not all that interesting. However, this guitar with the model of New York would be impossible to make any other way, as every part of the design is created in one piece at the same time, with all the objects in it as you see them.

So making parts that are more complicated becomes a big advantage, whereas with conventional manufacturing, you have to keep everything simple enough to do it in the best possible way. One area that's going crazy right now is jewelry, as jewelers are suddenly creating these amazing models that you couldn't make any other way. And they're not even having to own a printer. Instead, they go to some of the online services that print it for you. So it's a whole new way of doing business.

Olaf Diegel:

Another big area that complexity allows is lightweighting. Making products that are much lighter. There's something called topology optimisation, which means you use mathematics to remove any material that's not doing anything useful. So if, for example, I did an analysis of this wine barrel in front of me I'd probably find 30% of the material in this barrel's doing nothing useful. So get rid of it. If you think about something like an airplane part, every gramme you save in an aeroplane translates to thousands of dollars of fuel saving in a year. So that's where areas like topology optimisation really start to add value.

And I've got an example of that. It's a little aluminium bracket. But this weights 60% less than the original component to mount an expensive bit of kit on a bicycle. If you're a bicycle racer, that's the difference between winning and losing a race, saving that weight. So a big area of growth right now is using 3D printing to make lighter components.

A tiny 3D-printed teddy bear

A tiny 3D-printed teddy bear Photo: RNZ / Paul Bushnell

Olaf Diegel:

So complexity is the first big advantage. The next big advantage is what we call mass customization. Let's imagine we're making products for everybody in this room. A handheld product - a phone, or something like that. The conventional way we do it today is to go around everybody in the room, measure all of your hands, average all those measurements together and design our product for that average hand to be able to press all the buttons. This means we end up with a product that doesn't actually fit anybody. It's compromised. The idea with mass customisation is to make a product for everybody in this room which is custom made for the user to fit perfectly. There are now companies doing shoe inserts, using a scan or iPhone picture of the bottom of your foot, and making an orthopaedic shoe insert them to fit you perfectly.

An audience member admiring one of Prof Olaf Diegel's creations

An audience member admiring one of Prof Olaf Diegel's creations Photo: RNZ / Paul Bushnell

Olaf Diegel:

The medical world is going crazy over this, because anything medical needs to fit your body, and all our bodies are unique. I've got a little vertebra replacement here printed in titanium. It's like a mesh designed for bone replacement. So if I  have an accident and I'm missing a chunk of bone, they'll print this in the shape it needs to be implanted. And the idea is my bone grows into the titanium. It's called osseo-integration - where the bone grows into the titanium to give a full-strength replacement.

Now think about hip replacements. Typically with current technology, it's a ball joint, screwed into the hip. And if your great grandmother has a hip replacement five or 10 years later, she needs to go to another operation to get it tightened. However, with this new technology, because you can make the outer surface porous, you have the bone growing into it, which means one operation that'll last you the rest of your life.

A variety of 3D printed objects including the prosthetic arm for Naya

A variety of 3D printed objects including the prosthetic arm for Naya Photo: RNZ / Paul Bushnell

Olaf Diegel:

Mass customisation is growing hugely around the world. One nice example we did about two years ago in Sweden was for a little girl called Naya. A two and a half year old girl missing the bottom half of her arm. So we created custom prosthetics with 3D printing. With a $300 3D scanner, we scanned her arm and made her a prosthetic that fits her perfectly. And this is the actual prosthetic here. We did two versions - one was with electric implants to pick up muscle movements to control a bionic hand. But this was the prosthetic that she could just wear for comfort because the parents didn't want her running with a $20,000 hand around the home.

And the key here is the socket fits her perfectly, because it's based on the scan of her own arm. Now this one's decorated with sort of a mesh pattern on the outside. But in the future we'll have an iPad app where she can drag dragonflies or butterflies or Hello Kittys onto it to customise it the way she wants it to. And I can't say for sure, but she seemed to almost be showing this off to her friends, saying "Look, here's something cool I've got." Conventional prosthetics are really ugly. With the stigma attached to prosthetics, people don't go up as often as they should. However, 3D printing allowed one customer who had tattoos on his left calf to have them printed them out for a matching prosthetic to make it look like a work of art rather than a purely functional, ugly object.

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Photo: Pixabay

Olaf Diegel:

My prediction is in the next five or 10 years anytime we buy a high value product luxury goods will expect it to be custom made for us. Let's say we buy a Louis Vuitton handbag, we will expect the handle to be made to fit our hand perfectly. It's already happening a lot with eyewear as it's expensive. They have systems now that will scan your face and then the computer programme will line up your lenses at exactly the right height to ensure that the prescription is perfect. It's an expensive technology. But when you're paying $700  to $1000, for a pair of glasses, the printing is actually a very small part of the cost. So it becomes a viable way of doing things, of adding value.

So, we have complexity, and mass customisation. The third engineering advantage of 3D printing is what we call part consolidation. In conventional manufacturing, we make lots and lots of simple parts and then assemble them together into one much more complex part. However, with 3D printing, we can take all of those simple parts and join them together into one much more complex part. So instead of your product being made up of 30, or 50, or hundred different parts, it’s now made up of one or two parts.

Globes within globes - all 3D printed

Globes within globes - all 3D printed Photo: RNZ / Paul Bushnell

Olaf Diegel:

This is a little sphere full of gears - all of those gears turn inside the sphere, but this whole ball is printed in one piece assembled ready to go. There is no assembly required, as the parts are printed with a gap between the moving parts, This allows you to make entirely working assemblies straight out of the machine. How is it achieved? Through a powder-based process. The laser melts each thin level of powder. So when you take it out of the machine, you play archaeologist, digging it out of the powder, which you blow out from between the moving parts. And you've got a fully functional moving part in front of you. An even nicer example of that is chain mail and fashion. The Black Panther movie, for example, featured incredible 3D printed costumes.

Machine part created by 3D printing

Machine part created by 3D printing Photo: RNZ / Paul Bushnell

Olaf Diegel:

If your part or product is really complex 3D printing is probably an option. If you want to make a product that's custom-made for the user, then it's a good player for you. Or if you want to reduce the number of components you have to keep in store. Anybody who's ever had to do stocktake will know it's a horrible job. You run around counting all the parts. Imagine that, you now, halve the number of components, that's where you're starting to really add value.

On the non-engineering side, another example is something called tool-free production. If you have an idea for a product, the cost to get it into reality is so high that it kills 80% of ideas. Now, if everybody in this room thought that they had a really good idea, it's probably a fair chance that 80% of those ideas would be dumb ideas. The problem is, how do we know, unless you can realize them, by turning them into some form of a prototype. With 3D printing there's no setup or tooling costs. You pretty much hit print and the next day, you've got your part ready to test for real. Then you might find that it's not such a good idea and you start over again, but at least you found out for sure.

Whisky Still created through 3D printing

Whisky Still created through 3D printing Photo: RNZ / Paul Bushnell

Olaf Diegel:

Over the last 10 years or so some of the technologies have gotten good enough that we can make the real part to sell to the customer. And that's where tool-free production really starts to play in, because now you've got your idea. You can print it, sell it to the customers. My guitars an example of that. I've sold about 60 of them since 2011 without any setup costs. I didn't have to go to the bank to say please can I have a loan to test out this idea? So that's the beauty, no capital investment is required.

Olaf Diegel:

One of the first animal prosthetics was for an American Eagle that lost its beak and a hunting accident. He got his beak shot off. So they scanned the beak of a good eagle, modified it to fit, printed it out and on literally glued it on with epoxy resin and save the eagle's life. So it's quite a nice feel-good story. The point of the story, though, is that you could have made that beak a hundred other ways. You could have whittled it out by hand, you could have done it on a CNC machine (such as a lathe controlled by a computer). The problem is, is it's too hard. And that difficulty means we don't try out a lot of ideas that might be really, really good.

There are now a lot of desktop printers that cost below $5000. I strongly believe every engineer, every designer, every artist should have one of these. They're too cheap not to have as a tool to trial ideas. Now don't misunderstand me - those printers are not the same as really expensive printers that we print guitars out of, and all these metal parts out of. But that ability to try out crazy ideas is invaluable. When they talk about innovation, they say you've got to fail fast and fail often. And from my point of view, with 3D printing, you can fail extra fast, and fail extra often. And to me, it's the only way you find out if your ideas are sensible or not.

About the speaker

Prof. Olaf Diegel

Prof. Olaf Diegel Photo: RNZ / Paul Bushnell

Dr Olaf Diegel is a professor of additive manufacturing at the University of Auckland. He is an educator and a practitioner of product development with an excellent track record of developing innovative solutions to engineering problems.

Over the last 20 years, Olaf has become a passionate follower of 3D printing. He believes it is a godsend to innovation as it allows designers and inventors to instantly test ideas to see if they work. It also removes the traditional manufacturing constraints that become a barrier to creativity and allows us to get real products to market without the high costs that become a barrier to innovation.

He also makes cool 3D printed guitars! 


Photo: University of Auckland

Raising the Bar was recorded in association with the University of Auckland