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Supply, demand, and 3D printing


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Supply, demand, and 3D printing

The other day I saw an ad for personalised 3D-printed busts. You go into a booth. They scan your head and shoulders. Then they print a three-dimensional biodegradable plastic you. Full-size.

Classical artists used to spend weeks or months hand-carving stone busts of prominent individuals such as Cleopatra. I have no idea what a classical bigshot would have paid to immortalise their head in marble, but I’ll bet it’s a lot more than my kids will expect to pay for a biodegradable bust to be displayed at their funerals. The price is determined by supply, demand, and constraints.

There is no technical limit on the supply of 3D printed plastic parts. The raw material is plastic, which can be made from sunlight and air. A suitable 3D printer costs about a thousand dollars. Plastic filament from Amazon costs $US30 per kilo. An unpainted bust from a “Mr Minit”-style shopping-mall booth should cost less than fifteen bucks. Adjusting for inflation, Cleopatra would have spent more than that on food for her sculptor, who was probably a slave. If you want to know why I haven’t rushed out and bought a 3D printer and set up a booth at Queensgate, consider this: If the product is so cheap, what's the point of owning it?

I reckon 3D printing will revolutionise manufacturing. But its most enduring impact will probably be something no-one has thought of yet. In the short-term, some people will go nuts over things they thought they needed but couldn't afford. But the novelty will wear off. How many ornaments can you cram onto one mantelpiece, anyway?

The Kode9 sports car hints at one possible future. It's a great-looking car, except for one small detail: It has eyebrows on its wheel-arches. If, as Top Gear (but apparently no-one else) says, it has three-D printed body panels, that's easily fixed. Just change the three-dimensional computer model and print new body panels.

Not many car manufacturers would let me print my own bodywork. They want me to be able to wrap my car around a concrete powerpole, hop out, and order a replacement over the ‘net while I’m waiting for the taxi to come pick me up.

There's nothing wrong with that. Motoring's fatality rate has falling by more than 95% since the mid 1920s. Better bodywork has been a big part of that. But, safety has become a constraint on the design of car bodywork.

With 3D structural modelling and 3D printing, car manufacturers will be able to design, engineer, and test custom-styled bodywork within hours. Perhaps in the not too distant future, cars will arrive at dealerships in skeleton form, with bodies printed and installed according to on-the-spot customer specifications.

Perhaps. Or perhaps not.

Perhaps manufacturers will find other ways to exploit 3D printing.

It all comes down to the basics: Supply, demand, and constraints.


Kevin Cudby is a Wellington-based Freelance Writer and Parametric Modelling Consultant who loves writing about cool new technology. Email him to discuss your requirements: hello {a} 

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