To meet projected growth in the second generation of its innovative press brake tooling, Rolla-V has invested in a DMG MORI NHX 5000.
Over 10 years ago, Rolla-V, based in Halesowen, West Midlands, patented its original design. By incorporating rollers in its dies it makes it possible to bend very small flanges near the edge of a component, eliminate distortion of holes near the bend line and produce a mark free finish on the component. Originally, this was seen as a niche product but, with the advent of the second generation Rolla-V, it has rapidly become a mainstream choice for fabricating companies, as each die can cover a wide range of thicknesses up to 30mm, reducing setting operations and tool inventory, and is available with tangs to suit all makes of press brake.
Previously the company produced the Rolla-V and special tooling on pre-owned vertical machining centres but, with 75% export and projected growth which is expected to double turnover by 2016, this method of manufacture was unsustainable. Chris Lawlor, General Manager at Rolla-V, says, “We have already invested a new Blohm grinding machine, so the next stage was to increase the productivity of the machining operations.” Working with DMG MORI, Rolla-V selected the NHX 5000 horizontal machining centre with twin pallets. By using tombstone fixtures, the company will be able to load up to eight parts on each fixture and hence cut 16 parts every night with unattended operation. Chris Lawlor adds, “With vertical machining, we get a build-up of swarf and associated problems with broken tools. Horizontal machining will solve both of these problems. Additionally, we have Renishaw probes for in process checking of the part geometry and tool breakage detection to avoid any problems during out of hours working. To cope with some of the larger fixtures, we have also had the table uprated to 700kg to allow us to make more parts as demand grows.”
Horizontal machining offers further advantages in the accuracy of positioning of the parts in the fixture. With vertical machining, swarf can be inadvertently trapped under the component, leading to scrapped parts and inaccuracy. With the NHX 5000, not only does it have hydraulic clamping, which gives a much more repeatable result, but swarf will also naturally drop away from the fixture. Furthermore, the Renishaw probe will check the position of each part and feed any discrepancy back to the machine control, automatically offsetting the toolpath to match the actual position of the component.
Once the Rolla-V parts have been drilled and machined, they need to be ground to achieve the necessary 10 micron surface finish and accuracy. Chris Lawlor says, “The Blohm creep feed grinder can remove material very quickly but, by machining parts more accurately on the NHX 5000 before they get to the grinding process, we will be able to reduce grinding times as well, as there will be significantly less material to remove, further increasing speed of production.”
|NHX 5000 plus operator at Rolla-V||Rolla-V dies fully assembled|
When selecting DMG MORI as a supplier, Rolla-V made extensive enquiries to reassure itself that it was making the right decision. Chris Lawlor says, “We contacted companies we work with in Japan who told us that DMG MORI was the number one for build quality and reliability, while end users in the UK assured us that, 15 years down the line the machine would still be as accurate as it was on day one. We also had detailed discussions with DMG MORI to establish the exact methodology for after sales service.”
The NHX 5000 will be dedicated to Rolla-V production, so that the existing VMCs can be freed up for blocking-up and the manufacture of special tools, which is an important part of Rolla-V’s business. Chris Lawlor adds, “The DMG MORI NHX 5000 will make a massive difference to our productivity and will enable us to make our expansion plans a reality. In the longer term we will be looking at further automation options from DMG MORI to add to the NHX 5000 to reduce costs and speed up production even further.”