Is 3D printing really going to be as disruptive as we are told?

Additive manufacturing is novel and it is cool. It fascinates engineers and enthusiasts alike. There are niche applications that additive manufacturing is able to do well, but despite enthusiasm, machines can struggle to pay for themselves – particularly in the shorter term. There is a lot of interest around augmenting conventional production processes to include additive manufacturing. However, the reality is that 3D printing is mostly used in addition to conventional processes. The question of how much value it can actually add to a process is difficult to answer. Those that have 3D printers say they can't live without them. Ask them why and it is often some variation on the themes of 'more innovation', 'better visualisation' or 'better communication'. Meanwhile, those that don't have one want one. Designer envy shouldn't be understated. 'I don't really know how it will help me, but I really want one' is actually quite a common standpoint. The good Be warned, 3D printing will make you popular. Friends you never knew existed will ask you to print absolutely everything and anything. Everyone is excited to see what the machines that have featured so heavily in recent media reports can really do. Accompanying all the hype and excitement is real, and substantial, business growth. The technology is not going away and is going to become an increasing part of the engineering design process. Gonzolo Martinez, director of strategic research at Autodesk, says: "If you have a 3D design in Inventor, for example, it takes literally about two minutes to bring it to the 3D printing software. That is in contrast to CNC equipment where you have to go through all the interactional tooling, tool path analysis, and generate G-code." Autodesk has been developing its software to support 3D printing much like normal printer drivers. It is, of course, a far more complex problem that uses simulations to act like a print preview of a document to allow users to be sure that objects print correctly and what the finish will be like. However, it is not a case of pressing print and there it is five minutes later. As a guide, to print something like a single size 10 shoe takes between 14-20 hours. However, as a designer himself Martinez finds the ability to see a 3D model as a physical object immensely attractive. "Take a latch that snaps together," he says. "In the software it looks like it will come together easily. But when you output it to the 3D printer you can see and hear them click together. There is so much you can do on the computer virtually but honestly, there is nothing that beats having the part in your hand to see how it connects." To investigate the power of 3D printing, Autodesk has undertaken two demonstration projects. The first was a chopper-style motorbike. The project lasted just two months from start to finish in which time all the design, simulation and printing of some 300 interoperable parts was completed. "We figured everything out in the software and then put the printer to work," says Martinez. "After 2000 hours we were able to output every single component of the motorcycle and put it together. We had absolutely zero errors of fitting." The bad The following year the team printed a turboprop engine with Stratasys. Like the chopper it looks great. However, despite checking form and fit and also some moving parts, the product is not a prototype, it is a 3D model. It is a modern equivalent of (and much better than) a balsa wood or clay model. This fact raises a fundamental issue: how useful is 3D printing as a prototyping tool? At present, 3D printing probably sits more comfortably at the conceptual design end of the spectrum where ideas can be quickly printed out, passed around the boardroom and shown to directors and customers. That is useful. But it is also a costly luxury that perhaps only the higher end of the engineering fraternity can afford. The high capital cost of professional machines and the accompanying cost of materials are making it difficult to justify to financial directors. The alternative is companies such as Proto Labs that offer rapid production of parts using conventional injection moulding and CNC machining. The unit cost is similar but parts are available in production-ready materials, can be physically tested and used for low-volume production. "A compromise with 3D printing is material choice," says John Tumelty, managing director of Proto Labs. "It is limited and sits closer to concept modelling than prototyping. "We've created software that can take almost any 3D CAD geometry and produce a part. I can't machine faster than anyone else, but I can get it into the machine faster. We can quote you a part in a couple of hours and make your parts in 24 hours, and the price is pretty comparable to 3D printing." The ugly Additive manufacturing is not yet where everyone wants it to be. The hype has exceeded the reality and, though a lot is possible, it is not there yet – either in price or capability. Those lower-cost machines on the market also need more development. "There can be an enormous amount of delamination, warpage and distortion in those component parts," says Dr Phil Reeves, managing director of Econolyst. "Consumer 3D printers have thermal management problems and there is also a huge amount of geometric limitation as most of them don't have quality support structure." So should you care about 3D printing? Yes, absolutely. The technology is here to stay and is developing quickly at the consumer end. And this is driving professional machines in terms of cost, capability, speed and materials. Although additive manufacturing will increasingly be used by design engineers, it is essentially another tool in the growing 'smart' toolbox. It may replace some processes where it offers distinct advantages, but it will not make traditional manufacturing, as we know it, redundant. Econolyst works with both end users and technology vendors to find competitive uses for 3D printing and ensure machines are fit for purpose. It has carried out numerous studies to predict where the technology can be used, when it will become more effective and truly accessible to the masses. "By about 2015 you will be able to make a metal iPhone case cheaper than machining it," says Dr Reeves. "Take additive manufacturing seriously if you are engaged in activities involving high-value, low-volume manufacture. However, medium volume is only around the corner. This technology fits perfectly in to the whole world of customisation. There is no point in bringing in 3D printing as a disruptive technology to replace injection moulding or CNC machining. You have got to do more and personalisation is perfect."