SPE holding firm with Lang Technik

Nottinghamshire-based Swiftool Precision Engineering (SPE) is a family owned business that produces safety critical parts for a global customer base.

To ensure that it remains at the forefront of manufacturing technology developments, SPE regularly invests in new machine tools, employing a variety of highly-efficient multi pallet 5-axis machines, multi axis mill/turn centres and high-speed twin pallet horizontal machining centres.

To ensure machines achieve their full potential, SPE recently invested in a range of innovative workholding devices from Lang Technik UK. Amongst other workholding, SPE ordered LANG Technik’s advanced stamping technology, Makro Grip Vices and the company’s Quick-Point workholding system.

Project applications engineer at Swiftool Precision Engineering, Alex Nelson explained the purchase and use of the company’s efficient new workholding systems: “Amongst other reasons, our continuing growth is driven by strategic investments and by our policy of constantly seeking ever more efficient ways of working. Having invested in expensive, high-yield machine tools we constantly explore ways of maximising their full productive potential.

“As our machine tools are usually engaged in high-value, relatively short machining runs, we recently investigated the availability of efficient workholding systems that would help to speed-up our non-productive changeover times and increase our productivity levels. The Lang equipment ticked all the right boxes.

“In a nutshell, we have slashed our job changeover times and achieved the production increases we were looking for. It helps that now much of the work associated with setting-up the next job due on our machines can be carried-out while a current job is being machined.

“For instance, within the cycle time of a currently running job, we use the Lang Technik stamping unit to make very accurate, minute indentations into our next to be machined workpiece blank before putting it into one of the Lang Makro-Grip vices.

“As the features on the vice’s jaw precisely engage with the workpiece’s pre-stamped indentations, we can achieve excellent holding power while only needing to apply minimal clamping forces. The quick loading/unloading nature of the Lang Technik system means much quicker job changeover times.

“The need for reduced holding pressure ensures that we are able to hold, from the softest to the hardest of materials, under all machining conditions without fear of component deformation or other damage,” Mr Nelson continues. Also, as the stamping unit makes its indentations into just the last 3mm of workpieces, we are now also making savings on material.”

The multiple advantages gained from the use of Lang Technik pre-stamping technology and Makro Grip Vices has ensured that it has become an established clamping method for ultra-secure 5-axis machining.

The toothed jaws of conventional vices must perform two distinct roles: as well as indenting workpiece’s material they must also hold the workpiece securely under machining loads. Commonly used vices are only able to exert a maximum pressure of approximately 4 - 6 tons, as a result, the effective penetration of their jaws into workpiece material can be problematic, especially when clamping harder metals.

Also, to ensure that the workpiece is penetrated, a vice’s teeth must remain sharp to stay effective. As teeth are exposed to high levels of torque and wear, when in use their clamping ability inevitably declines. Therefore, when using conventional vices during the machining of soft, distortion prone materials, jaw teeth also tend to lose their holding power and work free from workpieces when under machining forces.

The use of Lang’s stamping technology overcomes these issues by applying up to 20 tons of pressure during the pre-stamping of workpieces which guarantees the creation of precise indentations, even when applied to the hardest of materials.

Following pre-stamping, as the teeth of Makro Grip Vices engage precisely with the pre-stamped indents, only low clamping pressure is required to hold a workpiece securely. In addition to holding the workpiece in the vice under the most severe machining conditions, the truncated pyramidal profile of the pre-stamped indents prevent the teeth from impacting deeper into the workpiece by providing a final penetration limit.

Despite the application of relatively low clamping pressure, the holding forces exerted on workpieces held in Makro Grip vices actually become greater, the harder and more resistant the material being machined is. Furthermore, as workpieces are prepared before being loaded into the machine tool, machine downtime is significantly reduced.

In addition to enjoying the efficiency gains delivered by Lang Technik stamping technology and Makro Grip Vices, SPE is also benefiting from the use of the supplier’s Quick-Point system which acts as a robust, precise interface plate between the machine tool’s table and workholding devices.

Designed to reduce set-up times and to allow work to be quickly and accurately transferred from one machine to another with high levels of location repeatability, Quick-Point is available in a wide range of variants to suit all machine tools and applications. When located on a Quick-Point system plate, the high-precision exchange of clamping devices, fixtures and workpieces between machines using the system can be carried out in seconds with repeatability within 0.005mm.

Lang Technik
www.lang-technik.co.uk

Swiftool Precision Engineering
www.swiftool.co.uk