Additive Manufacturing and the battlefield: What next?

Additive Design Consultancy is a design engineering company dedicated to the design of components to be additively manufactured for the defence and aerospace industries. Using the latest AM design software, analysis tools and a great experience of the defence industry, ADC offers its customers access to the advantages designing of AM can offer, in either structural, fluid or thermal applications.

It is fair to say that additive manufacturing is getting a lot of people, in many industries, very excited. With all of its promise for speed of component manufacture, performance improvements of products and a new meaning to the phrase; zero stocked item, many governments and defence departments are thinking about how to apply the capability of additive manufacturing to the support of armies in theatre.

The idea is simple. Part A breaks. Part A is not stocked, is a long way away or otherwise unavailable. 3D print part A and get the product up and running again tomorrow. This could be applied to parts of a combat vehicle, a manpack or anything else used by combat troops or support staff. With additive manufacturing you can potentially have the replacement part in your hand within a number of hours. The sheer scale of its application could enable advanced forces to travel a great deal lighter than they have before, and they would be better supported. Need a new stainless steel spanner for that hard to reach nut on the engine of a Typhoon? No problem, the engineers can print one. Need a new Aluminium control arm for the engine of that covert submarine sitting at the bottom of the Pacific Ocean? No problem, the submariners can print one.

You see additive manufacturing does not only help the support of the troops, by virtually having any replacement component on hand without the need to transport any, but it could also allow more complex mission planning, better utilisation factors of key equipment, and generals better ability to wage war. In wars, attrition rates are critical to success, those that can fix their machinery quicker have a better chance of winning.

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The idea of using additive manufacturing in the supply chain is a great one. It’s now time to push the conversation along a bit and talk about some of the real world complexities that need to be considered.

The 3D printing machines

In general, 3D printing machines are a self-contained environment. However, the current art is designed to sit in a clean room at room temperature, not a dusty hangar in the Middle East. This is an easy one though. The machinery can be redesigned to make it more robust, perhaps to allow it to be airdropped, and working in a larger range of environments. By applying standard knowledge of environmental factors, and perhaps housing the machinery in a positive atmosphere inflatable room, most of the challenges can be addressed. Governments could easily produce a specification for the equipment, and manufacturers would just need to follow the dots to qualify their product.

The post processing

Unfortunately parts that come out of a 3D printer, are not always immediately ready for use. Metal parts come out welded to a base plate, which need to be wire eroded apart. They may have a lot of support structure that needs to be removed and cleaned using a bead blaster. Bearing or mating surfaces may require machining to get a good enough surface finish. Holes may need to be threaded. In the instance of high end engineering (defence, aerospace, space, motorsport etc) most parts will require some sort of finishing to make them useful. It is a simple fact of life. There are some companies that claim to offer hybrid manufacturing machines which can 3d print and machine away material, and these are likely to be very useful, but you will still need other equipment, such as bead blasting, wire erosion and polishing equipment to complete the part. So let’s presume if you want to 3D print parts, you will need some sort of support machinery to ensure those parts are fit for purpose. These are less likely to require redesigning, as they are pretty inert and do not need a controlled environment in order to work. In fact it is a fair bet that most armies travel with some type of machinery as a general course anyway.

The 3D printed model

Now, if we go back to the analogy of 3D printing Part A that broke earlier, we have to look at the design of it. Part A could have been machined, or cast or produced by some other manufacturing method which was not 3D printing. It would have been designed for the manufacturing process intended to create it. Therefore, it is safe to assume, if you plug that exact same model into a 3D printer, you are likely to get nothing useful out of the printing machine. That is because, like all manufacturing methods, 3D printing has its own set of design rules, required to ensure a successful print. Yes, 3D printing moves the boundaries of what is possible with regards to part geometry, but it doesn’t do away with them entirely. So how could this work in theatre? Ideally the parts would be redesigned, prior to being required, by either the OEM or a 3rd party design consultancy like Additive Design Consultancy, to allow them to be manufactured using additive manufacturing. That way, the model could be ready to go exactly when you need it. Now chances are, something will break which does not have a 3D printable library model. In this case, the original model could be redesigned to allow it to be printed in a reasonably short space of time, certainly quicker and cheaper than one could be sent from stores and flown into theatre.

The redesign of said component has its own particular considerations. The structural and performance aspects of the part will need to be preserved, or at least for long enough that the printed part is useful. Not all replacement parts are required to be a like for like replacement. Say for instance on ground equipment or on a non-critical system, they could be designed to last for a month, or so many usages, allowing them to be made from an inferior material, that is readily available. They may just need to last long enough for an OEM replacement to be delivered in due course. An Engineer could analyse the part for its structural properties, using simulation software, and ensure the characteristics are met, or nearly met, depending on the application and expected life expectancy of the replacement. This could be done remotely, and only requires the original part model from the OEM, and could be done by a third party. Yield strengths and fatigue limits can be found using simulation, and applied to the new model.

This idea of a temporary replacement could negate any need for qualification or traceability normally associated with an OEM equipment, however this is quite a can of worms that would need complex agreements between OEM’s and end users, as would this nullify a warranty? Or could this be considered a special case? Who knows, it is likely to involve lawyers and high level risk analysis.

In essence I think the technology is ripe enough to begin field experiments, perhaps using 3D printing bureaus away from the battlefield at this stage, until more robust and suitable printing machines are produced. It would be wise to test the supply chain with regards to redesigning the components and fitting them on a product in service. This would give you a clear indication if the process is valuable enough, and highlight the next level of challenges to overcome without investing too much on infrastructure.