TECHNOLOGY
Insight into the CNC-controlled processing of gemstones
Extending the limits of the possible
The material of gemstones places very special demands on both people and machines. At Groh + Ripp every challenge is faced with expertise, experience and modern technology.
Coloured gemstones are highly versatile with regards to their uses. They have long expanded beyond the field of jewellery, with their various characteristics making them also of interest for potential use in technology and laboratories. In addition, many of the major watch manufacturers also use dials made from gemstone and mother of pearl, lending their watches a highly individual appearance and a unique character. Groh + Ripp supplies a wide range of objects to many different companies, including leading research establishments and a large number of watch manufacturers from all around the world. The range extends from thin cover glasses used in microscopy to accessories for watches and movements and on to complex large-scale objects such as sculptures, plinths for statues and cases for large clocks.
Machines working on the µ scale open up new possible areas of use for gemstones.
In the technical department objects are realised whose use is only evident at second glance: these are purely components. The dials or case rings made from materials such as turquoise, lapis lazuli, coral, opal, malachite, onyx, mother of pearl, meteorite, hawk's eye, jasper and synthetic sapphire represent just a part of the whole. Their elegance is only truly unfolded when they are processed further. When the dial sits beneath a gently domed sapphire crystal in a metal case, when the hands, powered by a quietly ticking movement, move across the fascinating material in composed elegance, then a completely different side to the beauty of the gemstones is revealed.
Achieving the high technical requirements is often difficult, because each material places its own demands with regard to how it is worked. The thinner the stone is cut, the more intricate the processing required and the more fragile the finished product will be. In addition, different hardness of the stones, irregularities such as cracks or natural inclusions always represent new challenges for the company.
Step by step, complex plans are transformed into the most precise products at Groh + Ripp.
This is why Bernd Willi Ripp and his daughter Sandra, who together manage the technology department at Groh + Ripp, are always looking to expand opportunities for processing gemstones. They are in constant search of solutions in order to realise projects that were previously thought inconceivable. This is why a great deal has been invested in computer-assisted production, which comprises, amongst other activities, annular sawing, surface grinding and milling machines. This machinery enables the creation of highly-complex pieces with tolerances in the range of 1/100 mm, in some cases even µ. The equipment used in the final inspection is also state of the art. Every development on the market is monitored — and where practical, the corresponding equipment is acquired. The result is an impressive machinery park in which mighty apparatus is used to create the most intricate objects, to the most precise specifications.
Here, for example, we can see how a special saw is used to saw a large block of lapis into extremely thin discs. Through the inspection window of a five-axis milling machine it is possible to see a tiny attachment, cooled by a jet of water, moving repeatedly over a plate of onyx barely one centimetre in size, slowly altering the shape of the jet-black stone in the pro-cess. And yet machines are incapable of performing all of the tasks. “Without the traditional craftsmanship the technology alone would not be sufficient. Despite all of the precision and care, the work of our cutters is indispensible,” explains Bernd Willi Ripp, “Craftsmanship and state-of-the-art technology need to complement one another. Only then is it possible for both to develop further.”
Only when high-tech and hand craftsmanship -intertwine is it possible for both to advance further.
The fact that both are to be found to a considerable extent at Groh + Ripp, that innovativeness meets dedicated craftsmanship, resulting in the ability to work almost any material required, means that the company is now in a position to fulfil nearly every customer request. Many customers of the company travel to the Ripps from all around the world, just to convince themselves that ideas can be realised and fulfilled with the required degree of perfection.
Groh + Ripp has established a reputation in the trade for mastering the extremely difficult task of transforming a technical drawing into a finished product.