Monday, August 14, 2006

CNC lathe reduces work cycles by 12%

In searching for a robust, high build specification turning centre, a machine shop found a slant bed CNC lathe that has since reduced cycle times on tough, complex parts by 12 per cent.
In searching for a robust, high build specification turning centre, a machine shop found a slant bed CNC lathe that has since reduced cycle times by 12 per cent. When Martin Beer, general manager at Plymouth-based specialist sub-contractor PTG Precision Engineers, wanted to increase capacity and throughput in line with customer improvement projects, his search centred on a robust, high build specification turning centre that could cope with the aggressive machining of cast iron components. After a review of several machines, he opted for a Super Kia Turn SKT300 two-axis slant bed lathe from Ward CNC of Sheffield - and not only is the machine satisfying PTG's demanding production routines, but it has also reduced cycle times by 12 per cent.

PTG has been established since 1977 and has evolved from a small toolmaking company into one of the most valued and progressive sub-contractors in the UK.

PTG is currently introducing lean manufacturing throughout its operation and continues to maintain high quality standards, including ISO 9001:2000.

'We have a fair spread of customers throughout industry including companies that manufacture hydraulic motors and pumps, compressor manufacturers as well as a customer base in the valve industry,' Beer explains.

'Recently we have been keen to enter into partnership agreements with many of our customers and suppliers, so that we can forecast further ahead using Kanban techniques.

To help ensure we had sufficient capacity to introduce such a method we required another CNC turning centre.' However, no ordinary turning centre would suffice.

At PTG, much of the machining is based on medium-to-high complexity cast iron or SG (spheroidal graphite) iron gear casing components.

This required a robust machine with enough 'grunt', as Beer describes it, to cope with the rigours of such tough materials in the aggressive fashion required to match the company's high productivity demands.

'We looked at turning centres from several suppliers,' he says, 'but when we saw the robust build quality of the Kia we knew we had found our solution.

Even more so when the machine's excellent value for money high-specification and support were added to the equation.' This latter is a point that Beer is keen to elaborate.

'Ward CNC has been first class.

The machine was delivered and installed on time, and commissioning and training went without hitch.

I have to say that since then (August 2004) the Kia has been very reliable.' Also significant is the fact that the machine is arranged in a production flowline, supplying parts to machining centres across a six-day, double shift work pattern.

'It means that reliability and speed of manufacture are key - and the power of the machine in combination with high technology insert grade tooling has enabled us to reduce cycle times by around 12 per cent.' With a 22/26kW spindle motor producing 3,000 rev/min, the SKT300 has a swing over the bed of 750mm, a maximum turning length of 720mm and a 90mm diameter bar capacity.

Feed rates are 20m/min and 24m/min in X and Z axes, respectively.

Featuring a 12-tool turret and a two-stepped geared headstock for high torque, heavy cutting - and optional programmable tailstock - the Fanuc-controlled SKT300 is designed to minimise non-cutting time.

Its single-piece cast construction boasts a three-layer solid bed and box ways on all axes.

The machine is fitted with a Q-Setter for quick tool compensation as standard.

'The Kia has been excellent,' concludes Beer.

'We have no complaints, and I wouldn‚t hesitate in recommending the machine.'