A favourite option for grinding

Investment in a Studer favorit CNC Universal Grinder at Beverston Engineering has substantially reduced process times and created new market opportunities for the precision engineering company. PES reports.

Prescot, Merseyside based Beverston Engineering is a company with a wide commitment to excellence in all of its endeavours. This has ensured that the company has achieved the highest accreditations and gained customer approvals from companies such as United Technologies Corporation, Rolls-Royce - Controls and Data Services, Pattonair and ChargePoint Technology.

Beverston specialises in the prototyping and manufacture of state-of-the-art engineering components for a wide range of demanding industries, including the aerospace, oil and gas and pharmaceutical sectors; areas where safety and accuracy are critical requirements.

Its experienced engineers have access to a range of advanced manufacturing technology and precise inspection aids, such as its multiple Mazak machine tools and Mitutoyo CMMs. The company also makes use of the latest administration and quality systems.

Since its inception in 1974, Beverston Engineering’s continuing expansion has resulted in a series of moves culminating in a relocation to the company’s present, 16,420ft² headquarters.

Much of the company’s expansion and diversification has been driven by customers’ requests. To enable it to satisfy these demands and to increase the scope of its key competencies, the company makes regular strategic capital purchases.

Gearing up for grinding

Typical of Beverston Engineering’s policy of continuingly broadening its range of in-house manufacturing capabilities, is the recent purchase of a Studer favorit CNC Universal Grinder.

Beverston Engineering managing director Rod Wah explains: “We see continual development as key to our success and remain committed to growing partnerships with existing customers and to creating new business opportunities.

“With the use of state-of-the-art CNC machines our team of engineers specialise in developing components for the aerospace, oil and gas and pharmaceutical industries to the highest international standards. Although we have several high quality manual grinders, our recent Studer CNC grinder acquisition has allowed us to further expand our range of grinding capabilities.

“The purchase was prompted by our growing need to grind demanding aerospace and pharmaceutical components. In accordance with our capital expenditure policy, in addition to enhancing our grinding function and benefitting our existing clients, we anticipate that the Studer CNC grinder will open up many further commercial opportunities for us.

“Although I was aware of Studer’s reputation for quality and precision, in addition to considering the purchase of its machine, we also looked at several other CNC grinders. Even though the alternatives were good machines, the Studer grinder had the highest specification and included all of the advanced features we were looking for. Given the premium nature of our new grinder, I was pleasantly surprised that our new machine was roughly the same price as the other grinders that we had looked at. Also, with the help of Mark Maurice, the owner of Micronz, the UK Studer Agent, we specified the favorit to match our CNC grinding needs.

“Our Studer favorit CNC Universal Grinder is not only delivering the required quality of work, we have been astounded at its speed of operation. We now anticipate further contracts made possible by the use of our Studer favorit.”

Studer’s favorit CNC Universal Cylindrical Grinding Machine is designed for grinding medium-sized workpieces in individual and serial production. Owing to the availability of a range of options, such as in-process gauging, a balancing system, contact detection and length positioning, the machine can be supplied to exactly match individual users’ needs.

Studer’s easy to use grinding software, with its proven pictogramming, means that even less experienced users can quickly program grinding and dressing cycles. Optional StuderGRIND software is also available, enabling special applications such as the profiling of grinding wheels for complex workpiece shapes to be programmed efficiently.

The favorit’s machine bed is made of solid Granitan S103. The excellent dampening characteristics of the machine base ensures outstanding surface quality of all ground workpieces. The use of Granitan S103 also leads to the service life of grinding wheels to be increased, leading to reduced downtime. In addition, temporary temperature fluctuations are compensated, providing high stability.

Guideway gains

V and flat guideways for the machine’s cross slides are moulded directly into the machine base and are finished with a non-abrasive Granitan S200 slideway coating. This patented surface structure prevents the slides from ‘swimming’ and also eliminates the stick-slip effect, present in conventional guideways.

The favorit’s longitudinal and cross slides are manufactured from high-quality gray cast iron and have highly precise, ground V and flat guideways. The slides rest entirely on the guideways of the machine bed through the entire speed range, which is the basis for excellent straightness – 0,0025mm over 650mm measuring length. The favorit’s slides are advanced by 40mm diameter circulating ball screws connected to a three-phase servomotor via torsion-resistant, bellow-type couplings. This arrangement enables the axes to achieve high process speeds and maximum precision with in-feed movements of 0.0001mm. Use of the swivelling machine table on the longitudinal slide enables the whole length of the surface to be ground and acts as a support for the workhead, tailstock and accessories.

The favorit’s turret wheelhead can be used for both external and internal grinding and can be equipped with an external grinding wheel and an internal grinding spindle. With extreme precision, the user can manually (2.5°) index the turret wheelhead in a Hirth gear within a swivelling range of -15°/+195°. The speed of the belt-driven internal grinding spindle can be infinitely variably regulated. Spindles are available with nominal speeds of 20,000, 40,000 and 60,000rpm.

The generously dimensioned barrel, designed for the deployment of Morse 4 taper centres, glides in the tailstock housing, whilst centre pressure can be adjusted with the precision required for grinding high-precision workpieces. Fine adjustment enables taper corrections in the range below 1μm when grinding between centres; also, to guarantee optimum thermal stability, cooling lubricant is passed through the tailstock, and totally covers the barrel and diamond holder.

A versatile universal workhead with MT5 fitting taper is capable of both live spindle grinding and grinding between centres. The low-maintenance workhead spindle is mounted on roller bearings and has an impressive roundness accuracy of below 0.0004mm. The machine’s fine adjustment allows for cylindrical corrections in the 1μm range during live spindle operations, whilst a pneumatic lifting process facilitates movement of the workhead during setup and resetting.

The machine’s Fanuc 0i CNC control with an active flat colour monitor (10.4”) is extremely reliable and optimally matched to the favorit’s drive elements. A manual control unit facilitates setup close to the grinding process, whilst a special electronic contact detection sensitron (optional) function enables downtimes to be reduced to a minimum.

The sophisticated mechanical engineering concept of the favorit is complemented by a grinding software program developed in-house by Studer. The software is continuously further optimised in collaboration with users of the software. Based on Pictogramming, the operator strings the individual grinding cycles together, and the control system generates the ISO code. Grinding and dressing process sequences can be programmed freely to optimise the grinding process.

Studer www.micronz.co.uk