Additive manufacture has designs on metal...
To my surprise, I've become a bit of a fan of the US Sherlock Holmes drama 'Elementary'. It took a little while to get used to the idea of it being set in modern day New York rather than old London Town, and that sidekick John Watson was now Joan Watson, but with its intelligent storylines, sharp dialogue and believable characterisation, it's become something of a favourite, enjoying 'series link' status on my recorder. This week's episode was particularly interesting from an engineering perspective (as well as for the cameo from Sean Pertwee as a disgraced inspector Lestrade). We all knew the husband had done it; the question was how could he have shot his wife and then disposed of the murder weapon so quickly? The police were on the scene within minutes, and there would have been no time to get rid of the gun, which seemed to indicate that a third party must have committed the crime.
All the clues were there, of course: in particular, the bottle of milk in the fridge when the couple were dairy intolerant. Turned out the milk was not milk at all, but acetone. The murder weapon was a 3D printed plastic gun, which was then dissolved in the acetone and popped in the fridge. Now, of course we can all sit and pick holes if we want to. The much hyped 3D printed gun isn't really capable of doing much harm to anything, and is probably more likely blast itself apart than blast a hole into the victim, leaving little pieces of gun all over the carpet that even the least competent investigator would have noticed. But it was fun, wasn't it?
Personally, I liked the way 3D printing was brought into the storyline. This is clearly the technology of the moment. And when you can buy your own 3D printer for beer money (well, quite a lot beer actually) from Maplin, it really does feel as though any of us could be making new breeds of devices from the comfort of our own homes. But just how useful is it as a manufacturing technology? We tend to think of it as being principally for prototyping, providing a quick and effective means of testing the form, fit and function of parts and products, enabling any design alterations to be quickly made before mass production. But surely that's the limit of additive manufacture.
Actually, this is a technology with a big manufacturing future. Costs may be high, but it can deliver huge benefits. There are functional details, for instance, that you can incorporate that you could never do with alternative casting technologies, perhaps delivering real performance benefits that would negate the increased cost. In the sports pages in this very issue, you can read about how race car steering knuckles are being produced using additive manufacturing, saving weight and increasing rigidity. Then there is the Amaze programme within the European Space Agency, which aims to build parts for jets, spacecraft and fusion projects using additive manufacturing. Printing metal parts for rockets would cut waste and save money, while enabling geometries that are impossible to achieve through casting. No great mystery, then; the technology provides the means and the motive. Elementary my dear Watson.
Mark Simms, 12 October 2013
Industrial Technology - NEWS