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To state that BCW Engineering has grown since it was set up in 2002 is somewhat of an understatement. Starting out in a small lock-up in Burnley, Lancashire, BCW Engineering is now known as BCW Manufacturing Group with an impressive manufacturing facility which is spread over 200,000 sq/ft. As a subcontract supplier to the automotive and aerospace industry, the company has over the years invested heavily in new facilities and plant machinery to support the production of its diverse range of component and material types now offering their services within different sectors such as commercial vehicles, mining, power generation and more.

Amongst its raft of machine tools are four MX-850 5-axis CNC machines from Matsuura. As the largest in the MX Series so far, these machines feature a maximum workpiece area of 850mm in width and 450mm in height and can accommodate billets of up to 500kg.

Looking inside one of these MX-850 machines at BCW, you may notice that there is no ordinary fixture clamping the workpiece in place. This particular bespoke fixture, instead of being machined in the tool room or supplied by a workholding specialist, it has been additively manufactured using the HP4200 Multi Jet Fusion 3D printer, also supplied by Matsuura.

With its ability to quickly produce functional prototyping and short-run production parts, HP\u2019s 3D printer offers a decidedly speedy alternative for producing fixtures. \u201cFrom design release, it takes 24 hours for us to have a fixture with a prototype or production part on the machine ready to cut,\u201d says BCW Engineering Support, Tony Kilfoyle. \u201cCompare this to the traditional route, which could take up to two weeks with having to first design the fixture, order the material and then machine it in the tool room.\u201d

One of the main differences producing fixtures in this way is that on the HP machine the fixtures are produced from plastic as opposed to metal. This is actually an advantage according to Kilfoyle, who says: \u201cOur tests have proven that plastic is sometimes better than mechanical metallic fixtures because it absorbs the forces of the cutter.\u201d

Another advantage is that 3D printing enables BCW to essentially re-engineer the fixture to be the best it possibly can be. This often involves making it look very different from conventional fixtures and, in fact, in many instances, it\u2019s impossible to machine.

\u201cFor instance, we can put structural strength into it, which you wouldn\u2019t be able to do with a normal part. We can build webs in and this stops swarf accumulation, which means that we don\u2019t need to place swarf traps on the 5-axis machine. We can also build in capillary holes to support wash or air pressure. It\u2019s really unimaginable what you can do with 3D printed plastic,\u201d describes Kilfoyle.

However, plastic isn\u2019t particularly weighty and the tables on the MX-850 5-axis can accommodate very large components that weigh a great deal. In such circumstances where a really large fixture is required, BCW will produce what it calls a hybrid fixture, which essentially entails building metallics into the fixture in order to strengthen it. \u201cFor instance, we\u2019d build a bush in the fixture, pulled from the back, or we\u2019d put counter balls in where we would insert metallic items,\u201d explains Kilfoyle.

Whilst hybrid fixtures offer increased robustness to equal that of metallic fixtures, what about the longevity of plastic fixtures? This isn\u2019t an issue either, according to Kilfoyle, because although BCW hasn\u2019t yet put any fixtures into full-time production, as it\u2019s currently being used for small to medium batches. This is down to how the fixtures, and in particular the threads, are engineered. \u201dIt really all depends on what diameter the threads are. Anything from M8 to M22 is not really a problem, the smaller threads can be a problem and that is when we\u2019ll put inserts in,\u201d he says.

Obviously, the biggest advantage of producing fixtures additively is time savings. Being able to produce a fixture in 24 hours not only saves time in the production of parts, but it also gives BCW an advantage when it comes to quoting for a new order. \u201cWe can print a fixture and we can actually dry cycle parts and cut it to get a true cycle time, which means that when we quote we are competitive,\u201d comments Kilfoyle.

Having decided to go down this route of producing fixtures on a 3D printer has been a real eye-opener for BCW, not least of all because it has made the company rethink how it would normally manufacture parts. \u201cIt\u2019s really enabled us to change how we go about designing fixtures. We can work with design concepts and then easily and quickly try them out before we go into a full-blown fixture. It\u2019s really very exciting,\u201d concludes Kilfoyle.