Need a clutch release lever for your Vauxhall Corsa? Not a problem. There are hundreds of suppliers ready to service your enquiry and it should be with you tomorrow. Cost: about £16. Porsche is now using 3D scanning and printing to produce rare parts.
From an article in Autocar by John Evans.
But what if you need one for your Porsche 959, an extremely rare car, parts for which you’re unlikely to get online, never mind over the counter? Until a year or so ago you would have had to get one specially made at great expense but, since 2018, Porsche has been able to produce the part on demand and at reasonable cost using 3D printing and, specifically, a process called selective laser melting.
This involves spreading a shallow layer of steel filings in a sealed container. Guided by CAD data derived from scanning an existing example of the part, a laser melts the material in the desired locations before another layer is applied and the process repeated until the component is produced. Another technique, more suited to plastic components, is selective laser sintering, where the material is heated almost to melting point as a laser fuses the plastic powder at predetermined points.
Porsche uses these processes – called additive manufacturing because they involve adding layers of material – to produce around 30 parts for its older models, for which creating tooling and producing them in the conventional way would be prohibitively expensive.
Porsche isn’t alone. Across the motor industry, companies large and small are using the same techniques to produce everything from prototypes or pattern parts for moulds to one-off, functioning components. They fall under the grand name of reverse engineering because they involve deconstructing a finished component to determine how to remanufacture it.
One company doing this work is A2P2, based in Nottingham. It’s at the back of a busy workshop that’s home to INRacing, a company specialising in the restoration, maintenance and sale of historic road and race cars and founded by a chap called Ian Nuthall.
When I visit, the workshop is filled with rare motors, including a 1959 Tec-Mec Maserati, a 1959 Lotus 15 once raced by Graham Hill, a couple of 1952 Cooper Bristols and a 1965 Autodelta Alfa Romeo GTA. A2P2 has had a hand in helping to keep them active, as I discover when I meet its founder, Alistair Pugh.
In contrast to INR’s workshop with its ramps, lathes and even a huge five-axis CNC milling machine, Pugh’s place is a high-tech oasis of calm. In one corner is a 3D printer, methodically layering up, in plastic, a bevel box for a pre-war, chain-driven Frazer Nash. Once completed, it will form the pattern for a sand cast moulding in metal. As it quietly goes about its business, Pugh draws my attention to the room’s other occupant: a 3D laser scanner. Looking like an angle-poise lamp but with a probe at the end rather than a bulb, it’s fixed to a sturdy metal table and connected to a laptop.
Pugh’s colleague, Alberto, shows how, by painstakingly moving the probe around a component – in this case, the diff casing from a 1952 Alta GP car – he can capture and digitise its every dimension, including the internal faces of the screw bores. The result is an accurate digital representation that can be converted into a CAD file for a 3D printer or into an engineering drawing for a machine shop to follow.
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