Workholding versatility for new machining centres 

CNF Precision Engineering has experienced significant growth over its 50 years driven in part by its willingness to invest in the latest machine tool technology.

The most recent evidence of this are the four Matsuura machining centres, the arrival of which has created a lights-out production capacity maximising the large pallet pools on the machines.

These four machines, along with a range of other high-end machine tools, has provided CNF with a capability of producing a diverse mix of work, from low volume batches running up to thousands, for industries ranging from aerospace and medical, which are its core activities, extending to the motorsport, automotive and scientific instrument sectors.

CNF Precision Engineering’s managing director Neil Fearnley explains his company’s philosophy: “With our investment policy we have created a working environment that allows us to be able to respond quickly to customer needs and provide the level of technical support and quality control to maintain 100% on-time deliveries and 100% quality assurance.

“We have developed our own, in-house, business management software to deliver efficient production control meaning we can schedule delivery of kits or single components via Kanban, direct to stock or, direct to the assembly line for customers. Through investment in the latest machines and the equipment supporting those machines, we have created a competitive edge.”

Adaptable base plates

This combination of multiple pallets and 5-axis machining at CNF called for a versatile workholding system and, as the company was using WNT for its cutting tools it was a logical step to tap into the supplier’s workholding expertise.

Key to the use of the WNT system was the versatility of its MNG Zero Point base plates that allow quick and accurate changeover from one set-up to another, with multiple set-ups possible on a single base plate, thanks to the option of one, two, three, four, six, and ten location points.

This alone can generate significant time savings and productivity gains. Initially every one of the 32 pallets on CNF’s Matsuura MAM72-35V 5-axis machine was equipped with single position MNG Zero Point base plates. With the arrival of the Matsuura H-PLUS 300-PC15 and MX-520 simultaneous 5-axis machine, works manager Mark Baron looked to expand its use and introduced double and triple location MNG base plates.

He explains: “The WNT MNG system along with the ZSG centric vices and ESG fixed jaw vices that we use have proved to be highly versatile. We have added to them as we have progressed, making use of the different jaw systems available for the vices. While the majority of our set-ups are single parts per pallet, the ability to mix and match vices on the MNG base plates is an obvious advantage and allows for extended unmanned operation.

“Another key feature is the enclosed leadscrews on the WNT vice system. We looked around and couldn’t find this feature on other vices. Given the number of pallets that we have, this feature is invaluable as we can’t afford the time to clean swarf from the leadscrews of all our vices, or indeed continually replace them due to swarf damage.”

With the WNT MNG Zero Point system CNF Precision Engineering can maximise the potential of its multi-pallet machines; set-up is speedy due to the single clamping screw on the system and repeatability is guaranteed to within 0.01mm. Its low profile of 30mm also makes it ideal for 5-axis machining.

Jaws and vices

Versatility is then created by the choice of vices and jaws systems available from WNT. At CNF, the main vices in use are the ZSG 3 and 4 centric vice and the ESG 100 single clamp systems. The ZSG range has a maximum gripping force up to 35kN and components up to 303mm in length can be held securely in its jaws, yet they remain very compact, a major benefit on CNF Precision’s high-end, multi-pallet, 5-axis machines.

The jaws used on these vices feature precision matched slides which result in repeatability of ±0.01mm, with added efficiency and accuracy aided by the use of a backlash free ballscrew. The ZSG 4 vices are available in three jaw widths of 80, 125 and 160mm while the smaller ZSG 3 has widths of 40 and 65mm available. For all of the vices a wide range of interchangeable jaws are available to clamp virtually any component.

The WNT ESG range of single clamp vices is also available in three jaw widths of 40, 65 and 100mm and as with the ZSG range, a wide variety of jaws can be attached for optimum versatility. Again, particularly with 5-axis machining in mind, the profile of the vices is very low – in the case of the ESG 100 the height of the vice is just 60mm from the MNG Zero Point base plate and even the larger ZSG 4 vices only stand 83mm high to the top of the jaw mounting.

This allows much better access by maximising available machine Z-axis movement. Programming is also simplified as all of the WNT range of workholding is available as 3D CAD models.

“The ability to download the CAD models of everything from front-end tooling to workholding from the WNT website and import them into our CAD/CAM system is a major timesaver. It eliminates the need for us to create our own files and also reduces the possibility of errors. This along with the technical support and the overall quality of product from WNT makes our life easier,” say Mr Baron.

CNF Precision, like any other WNT customer can call on the support of a team of technical sales engineers and applications engineers. In CNF’s case WNT’s technical sales engineer Warren Howard was on hand to offer advice where needed.

He comments: “WNT is very well known for its high performance and precision cutting tools, but our workholding 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 that there is very little that can’t be machined using our workholding solutions. Choosing the right product can deliver exceptional productivity gains, especially on machines such as the Matsuura machines at CNF Precision, which are working around the clock, often unmanned.”

WNT www.wnt.com

CNF Precision Engineering http://cnfengineering.com