CNF Precision Engineering has achieved significant growth in recent years. Much of this is attributable to the company investing in the latest machine tool technology — such as the four recently installed Matsuura machining centres, which have large pallet pools and provide a ‘lights out’ production capability.

These four machines, along with a range of other high-end machine tools, give CNF the ability to produce a diverse mix of work, from low-volume parts through to batches running to thousands.

The company supplies the aerospace and medical industries, which are its core markets, as well as the motor-sport, automotive and scientific instrument sectors.

Managing director Neil Fearnley says: “Our investment policy gives us the ability to respond quickly to customers’ needs and provide the level of technical support and quality control required for 100% on-time deliveries and 100% quality assurance.

“We have even developed our own in-house business management software, to ensure that we have efficient production control and can schedule the delivery of kits or single components via kan-ban — directly to stock or to customers’ assembly lines. Investing in the latest machines and supporting equipment has given us a competitive edge.”

CNF’s combination of multiple pallets and five-axis machining required a versatile work-holding system; and as the company was using cutting tools from Sheffield-based WNT (UK) Ltd (www.wnt.com), it seemed logical to consider the latter’s work-holding products — in particular its MNG Zero Point base plates.

These allow extremely quick and accurate change-overs from one set-up to another, with multiple set-ups possible on a single base plate, thanks to the availability of one, two, three, four, six or 10 location points.

Initially, every one of the 32 pallets on CNF’s Matsuura MAM72-35V five-axis machine was equipped with single-position MNG Zero Point base plates. However, with the Matsuura H-PLUS 300-PC15 and MX-520 simultaneous five-axis machines that soon followed, works manager Mark Baron introduced double- and triple-location MNG base plates.

He said: “WNT’s MNG system, ZSG centric vices and ESG fixed-jaw vices have proved to be highly versatile. While most of our set-ups involve single parts per pallet, the ability to mix and match vices on the MNG base plates is an obvious advantage and allows us to accommodate extended unmanned operations.

Another key feature is the enclosed leadscrew on the WNT vice system. Given the number of pallets that we have, this is invaluable to us; we can’t afford the time that would otherwise be required to clean swarf from leadscrews — or replace them when they suffer swarf damage.”

Fast set-up

With the MNG Zero Point system, CNF can maximise the potential of its multi-pallet machines; set-up is quick, due to the system’s single clamping screw, and repeatability is guaranteed to within 0.01mm. Furthermore, its low profile (it is just 30mm high) makes it ideal for five-axis machining.

Further versatility is provided by the variety of vices and jaw systems available from WNT. At CNF, the vices most used are the ZSG 3 and ZSG 4 centric vices, along with the ESG 100 single-clamp system.

Vices in the ZSG range have a maximum gripping force of 35kN and can accommodate components up to 303mm long. The jaws used feature precision matched slides that give a repeatability of ±0.01mm, with efficiency and accuracy ensured by the use of a backlash-free leadscrew.

ZSG 4 vices are available with jaw widths of 80, 125 or 160mm, while the smaller ZSG 3 has widths of either 40 or 65mm. For all these vices, a wide range of interchangeable jaws is available, making the clamping of virtually any component straightforward.

The WNT ESG range of single-clamp vices is also available in three jaw widths (40, 65 or 100mm); and as with the ZSG range, a wide variety of jaws optimises versatility.

Again, and with five-axis machining in mind, the profile of the vices is very low; the ESG 100 is 60mm high, while the larger ZSG 4 vice measures just 83mm to the top of the jaw mounting (this allows much greater access by maximising the available Z-axis movement).

Programming is also simplified, as 3-D CAD models of WNT’s work-holding products are available. Mr Baron says: “The ability to download the CAD models of everything from front-end tooling to work-holding from the WNT Web site and import them into our CAD/CAM system is a major time-saver, eliminating the need for us to create our own files and reducing the possibility of errors.”

Like many WNT customers, CNF uses the support available from the company’s applications engineers and technical sales engineers; in CNF’s case, this support is provided by Warren Howard.

He says: “While WNT is well known for its high-performance cutting tools, the company’s work-holding systems are playing an increasing role in helping customers meet their productivity targets.

“The versatility and choice of systems — from the MNG Zero Point, through vices and fixturing towers to magnetic clamping systems — means there is very little that cannot be machined using work-holding from WNT.

“Choosing the right work-holding solution can deliver exceptional productivity gains, especially on machines such as the Matsuuras, which at CNF Precision Engineering are working round the clock — often unmanned.”