Following the investment in a CNC slant bed chucking lathe a leading producer of extrusion dies for plastics and rubber insulation has cut extrusion die machining up to 70 per cent.
Following the investment in a Colchester Tornado 220 slant bed chucking lathe Aspin Engineering, a leading producer of extrusion dies for plastics and rubber insulation used on a wide range of cable and wire products, has cut extrusion die machining up to 70 per cent. The company has also adopted hard turning of materials up to 45 HRC and reduced grinding requirements by a third. Aspin Engineering has since expanded its business into general sub contract machining.

Says managing director Dr Anton Aspin: 'We decided to buy the Tornado 220 CNC lathe following a visit to the Colchester Sales Technical Centre in Heckmondwike.

Originally selected from a shortlist of three turning machines, it was the performance, accuracy and overall value for money that were the major advantages we determined.' He follows on to outline: 'I was particularly impressed by the construction with its wide slideways and polymer concrete filled base which gives a high level of stability.

In my view, stability is an important prerequisite in a machine for holding the tight tolerances which we regularly have to work to on a wide range of precision extrusion dies and various other turning projects.' Dr Aspin's comments on the construction are confirmed following the Tornado's installation in the company's 4,500 (square feet) factory unit on the Moss Lane Trading Estate in Greater Manchester in April.

Cycle times on H13 and P20 tool steel extrusion tooling have been cut in half and 316 stainless steel mixer part machining times have been slashed by almost 70 per cent.

But there have been even further benefits as Dr Aspin explained: 'We have been able to eliminate around a third of our cylindrical grinding work as the Tornado can turn extrusion points and dies consistently to an almost unbelievable accuracy of + 5 microns.

What's more, we've also been able to comfortably machine a range of toughened materials up to 45 HRC, using standard tooling.' Aspin Engineering has found the GE Fanuc B series 21-i controlled Tornado 220 is quick and simple to program.

In fact, the company reckons that it is also able to produce single parts economically on the lathe as it is so easy to generate part programs.

However, batch sizes of between five and 10 are deemed more realistic.

It is the ability of the machine to effectively handle larger volumes of work that is seen as important for expansion of the Aspin Engineering business and has enabled additional savings to be created by the company.

For example, when Aspin received a large order for extrusion parts late last year, it had to spend around GBP 10,000 over a three month period on subcontracting much of the turning due to capacity problems in achieving the scheduled delivery dates.

As Dr Aspin added: 'This really motivated us to look at being self-sufficient and buy a new CNC chucking lathe.' When Dr Aspin discusses the purchase he maintains the lathe's all-round performance and accuracy is directly attributable to its patented 'Duo-Stable' construction which provides a highly stable, true 60 (Degrees) slant bed turning platform.

The base foundation with its engineered polymer concrete fill, strategic reinforcement and integral cast iron bed, reflects an increase in machine weight of some 50 per cent which is coupled with a corresponding 25 per cent improvement in damping.

'This is where the 'performance and accuracy factors' are created and the machine easily copes with the 22 kW spindle power making the larger 250 mm diameter chuck capacity and tailstock options that we ordered meet our planned requirements.' Other advanced technical features of the machine include: larger headstock and a stiffer, five-bearing spindle design; wider, lower and heavier slideways; and improved thermal characteristics - which collectively provide the stability factor required for really high performance machining.

Set-up in 1984 and employing 14 people, Aspin Engineering's work load is now split 20 per cent between producing wire and cable extrusion dies, 40 per cent on general subcontract work and other products and 40 per cent on added-value small assemblies.

The company has CNC machine tools of which two are vertical machining centres, a Colchester Electronic lathe and two thread grinding machines.

Its production of dies for insulating cables ranges from telecommunications work requirements of 0.5mm diameter right up to 152mm diameter for power cables.

Extrusion points and dies range in size from 20mm to 250mm diameter while stainless steel rotors and stators are also produced in diameters up to 200mm.

The company's own Cavity Transfer Miser (CTM) system product, which significantly improves the mixing/blending performance of an extruder, is produced in sizes from 20 mm to 600 mm diameter.

There's no doubt that the Tornado 220 has made a big impression since its arrival at the company's Whitefield works earlier this year.

As Dr Aspin concluded: 'The Tornado has extended our capacity, widened our scope of operations, eliminated certain grinding operations and, allowed us to look at work we could never have economically handled before.