Good Enough for the Swiss

For every high-end Swiss watch brand there’s a mass-market product that relies on suppliers like family owned precision engineering firm and Haas customer Pierre Bercher SA. These relatively low-cost watches may not be as coveted as the Piquets or the Pateks of this world, but they trade on their Swiss-ness just as much as their pur sang cousins. They tell the time, too.

Bercher SA makes plastic parts for some of Switzerland’s best-known watch brands, although Monsieur Bercher senior, founder and CEO, prefers to talk about how they make what they make, rather than who they make it for.

‘Seventy percent of our work is for Swiss watch companies,’ he says (he’s even more reluctant to talk about the other 30% of his company’s revenue). ‘Typically, these companies want fast turnaround and the peace-of-mind that comes from knowing that their suppliers know what they are doing.’ The other reason they continue to use local companies is that generally, people don’t want a ‘Swiss’ watch that’s made in China, even a low or mid-price brand. It’s about provenance.

Most of Switzerland’s watchmakers are located in what the country’s tourist office refers to as Watch Valley: a narrow corridor that stretches from Geneva in the south of the country to Basel in the North, along the arc of the Jura mountains.  Bercher SA is based in Cernier, just outside of the arc, but strategically well placed to serve the industry’s big names.

The company’s workshop is divided in two by a wall of windows. On one side of the glass there are seventeen Arburg plastic injection-moulding machines. The other side contains a menagerie of manual and semi-automatic machine tools, as well as three Haas CNC machines. By the window, lit by the sunlight reflected from the deep fresh snow outside, are two 15,000rpm Haas VF-2 vertical machining centres, both flanked by Agie Spirit die-sink EDM machines. Each pairing is a self-contained cell; the Haas’ machine copper electrodes used by the Spirits to make the steel moulds that are used on the Arburg injection moulding machines.

‘The moulds we make on the Agie EDMs are complex,’ says Bercher, ‘so we often need multiple electrodes to make the desired form. The shape of the electrode is, in part, that of the object to be moulded. Each electrode is machined in copper, which is why we chose the Haas VF-2s with 15,000rpm: because the material is relatively soft but we need to achieve and maintain high precision and excellent surface finish.’ Electrode walls are often machined to thicknesses less than .5mm and heights of 5-6mm, which means they can easily burn or break up.

Bercher SA is able to produce runs of up to one million plastic parts from a single steel mould.

‘Over the course of a typical year we may make as many as 40 moulds and produce up to 14 million finished parts. Runs of a million or less are small numbers for one or two of our customers, which is why they prefer to source them from outside.’

Forty moulds a year doesn’t sound like much machining, but some moulds need more than a dozen copper electrodes to achieve the complexity and some electrodes take hours to design, let alone to machine.

‘With die-sink EDM there’s an electrical impact on the electrode but no contact with the workpiece,’ says M. Bercher, ‘so an electrode lasts quite a long time. Even so, it’s rare that we’ll reuse one. Our customers change designs frequently. Their products tend to be fashion accessories rather than investments.’

The other Haas machine in the Bercher workshop is an Office Mill OM-2 with 30,000rpm, presided over and operated by Bercher senior’s son, Dan.

‘This is our latest machine tool investment,’ says senior. ‘It’s a great, small machine with excellent accuracy and capabilities. We are using it to make even smaller electrodes with wall thicknesses of as little as 0.3mm.

‘Like most of the parts we make, we get a 3D CAD file from the customer, from which we use Virtual Gibbs to generate a program for the electrodes. It’s a powerful combination: the Haas and Gibbs CAM. With its 30,000rpm spindle the Haas machine’s perfect surfaces. Why spend more? A Haas costs an awful lot less than some alternative machines, but it does the job just as well.’

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