Body jewellery is not something you immediately associate with high technology manufacturing. But for Darren Sell, founder of F-Max Worldwide, it is the key to providing the precision and flexibility that his customers demand.
A key investment for F-Max has been a Chiron FZ 08 S cell that is used to manufacture components for navel piercing jewellery. The Chiron machining centre is integrated with a pick and place load/unload system and a fully automated workholding fixture, supplied by Hyfore Engineering of Coventry, which is mounted on a 4th axis NC drive fully integrated with the machine control.
The cell allows F-Max to produce a common component for several styles of jewellery in one operation.
Darren Sell originally qualified as a goldsmith and started in business designing and making high-class jewellery. He always had an interest in mechanical engineering though so the move into a volume manufacturing environment was a natural step – today he employs 25 people.
The Chiron installation manufactures machined titanium balls that form the basis of navel piercing jewellery. A series of concentric holes provide the setting for a gemstone, while a further 1.5 mm hole, at a precise angle to the setting allows a pin to be fitted to the ball – this is the part that actually goes through the piercing.
It might appear to be a simple component but accuracy and consistency are of the highest importance – and aesthetically it has to be perfect. When the concentric holes are machined in the top of the ball a very narrow rim is left around the edge of the hole. As Darren Sell explains, “The machine and workholding accuracy need to be spot-on to make sure that the holes are absolutely centred – the eye can see misalignments that you can hardly measure. The centre height must be absolutely right too or else you can get a visible flat on the top.
“The 1.5mm pin is a press fit into the ball so that hole has to be right to within a couple of microns and dead true to centre the pin properly. If there are any problems it will not press together properly. Since we are working from polished stock there is no opportunity to rework these components – they have to be right first time.”
In operation, titanium balls are fed four at a time into the pick and place grippers; they are then transferred into a four-sided workholding cube, mounted on the 4th NC axis. The fixture which indexes round to the machining position then automatically clamps the four balls. After the top holes have been produced the fixture rotates to allow the side holes to be drilled.
The advantage of Chiron’s moving column design is that the fixed worktable provides an extremely stable platform for this fourth axis and automated fixturing and also for the pick and place automation. The speed of the Chiron machining centre is also important to Darren Sell, particularly the chip-to-chip and tool-to-tool times. The unmanned cell runs 24 hours a day.
Perhaps the biggest benefit for F-Max is that the Chiron installation has allowed it to improve its manufacturing process. In the past the holes for the pins were drilled as a first operation and the pins assembled so that the parts could be located for the second operation of machining the settings. As the pins come in a number of designs this meant that the part was then fixed as being for a particular style of jewellery. The parts produced on the Chiron provide a common starting component for a number of styles of jewellery and so give F-Max greater flexibility in scheduling its manufacture.
The other great advantage of producing the parts in one operation is quality.
Darren worked directly with both Chiron and Hyfore Engineering to develop this truly one off automated system.
As Darren Sell says, “Before there were lots of operations, it was more hands-on and so there were more chances of it going wrong. Now we have a flexible, quality component for a multitude of products.”
ENDS
31st March 2002
For more information please contact:
Andy Sandford
Sticklebacks Communications
Tel: 01737 270 648
Mobile: 07971 436 644
Captions
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Left: the finished navel-piercing jewellery Right: the machines titanium ball showing concentric machining of the setting and side hole for the pin
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According to Darren Sell of F-max the Chiron installation has given him a flexible, quality component for a multitude of products
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The machined titanium balls can be used to produce of multitude of finished products
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A fully automated workholding fixture, supplied by Hyfore Engineering, is mounted on a 4th axis NC drive fully integrated with the machine control.