Discipline: Mill/Turn
Machine Type: CNC lathe
Manufacturer/Model: INDEX G200
Materials: Aluminium, stainless steel, titanium
Client Type: OEM
Sector: Medical


In the mid 1990s, Chas A Blatchford & Sons bought an INDEX G200 turn-mill centre, having decided it was the best machine for manufacturing metal components used in prosthetics for lower limbs. A recent reappraisal of machines on the market showed that the German machine tool builder’s technology is still the best production solution, 15 years on.

The Challenge

The original machine had been running 24 hours a day since it was installed, so was ageing and needed replacement.

The Solution

In May 2010, Blatchford bought another G200 through UK agent, Kingsbury. It is of identical construction with two turrets and twin opposed C-axis spindles, but has undergone significant improvements since the original was introduced. Among these is a more powerful control, the INDEX 200-4D based on the Siemens 840D Powerline, which has sufficient memory to drip-feed entire programs for machining even the most complex of Blatchford’s components. Furthermore, processing power has doubled, enabling more accurate contour control and allowing enhanced look-ahead for producing a better surface finish. The required 0.8 microns Ra finish is now easily achieved. Other upgrades to the second-generation G200 are a doubling of linear acceleration of the turrets to rapid traverse rates that are 50 per cent faster at 45 m/min and 22.5 m/min in X and Z respectively.


There are about 40 part numbers for ankle products machined from bar up to 65 mm diameter on the G200. All parts need some prismatic machining and in certain instances, turning accounts for less than 50 per cent of the cycle. Proven programs were transferred seamlessly to the latest machine with the assistance of new post-processor software provided through Kingsbury. As a result, Blatchford’s worldwide delivery schedules were unaffected.

“The uprated-specification G200 has resulted in reductions in cycle times of up to 28 per cent. It is a direct result of the faster machine movements and more powerful control, as exactly the same programs are being used as on the older machine.”

Ian Keeley, Senior Manufacturing Engineer.