Better punching and profiling

Sub-contractor Hermitage Sheet Metal, Hitchin, Herts, has installed a Strippit ST-1212 20-ton CNC turret punch press, manufactured by LVD (01295 676800) to meet increased demand. The flexibility of the Strippit ST-1212 punch press's turret configuration, along with a fully programmable ram system, has reduced Hermitage's set-up time by 50 per cent, increased throughput by 25 per cent, and maintained a high quality of punched and formed components. Image: Hermitage's David Spencer Hermitage was established in 1965, producing parts for electronics companies. Its business steadily expanded and diversified into high accuracy sheet metal work. Today, the 25-employee shop fabricates precision electronic components for the aerospace and defence industries, as well as for medical applications, ultrasonic, radar and analytical instrumentation. Customers include BAE Systems and Lockheed Martin. The Strippit machine, fitted with GE-Fanuc 180i CNC, replaced older punching machinery, with managing director David Spencer (picture, above) saying he selected the ST-Series machine because of the flexibility and productivity it provided: a 29-station turret capacity reduces set-up time, an easy-to-use control simplifies programming, and a fully programmable ram provides enhanced punching and forming capabilities. Also important was the thin turret tooling design, as the company has an £80,000 investment in thin turret tooling. The managing director researched four punch press manufacturers and selected the Strippit ST-1212, based on his experience with a past Strippit machine, and the relationship established with LVD prior to and during the sales process. "I felt comfortable with the entire LVD package – sales and service," he says. "LVD offered us what we needed and didn't try to force us down the road of changing all our tooling! I felt that they listened to my requirements, both technically and commercially, before they recommended their best package. Overall, they treated us more personally than the competition, who gave us the impression that we would be just another number." The versatility of the ST-1212's turret design allows every station to accept shaped punches and dies. Hermitage keeps a selection of commonly used round and shaped tooling in the turret, thus minimising subsequent tool set-ups. Three 88.9 mm gear-driven auto-index stations are programmable, making it possible to punch shapes at any angle, which adds more flexibility and helps provide a high finished part. The large auto-index stations accept a variety of indexable Multi-Tools to expand turret capacity and further reduce setup requirements.Two 50 mm turret stations are used to house larger tools. Hermitage takes full advantage of the turret, using form tooling to reduce secondary operations, and Wilson Wheel tooling for quick and efficient cutting or forming of straight or curved shapes, without nibbling. "We're able to rotate larger tools, even forming tools, which gives us more tooling and turret flexibility," remarks Mr Spencer. "And we now have wheeling capability – the ram/stroke for forming works well, quite useful for strengthening ribs in thinner aluminium." Hermitage's punch press features a fully programmable hydraulic ram system. The programmable ram control minimises part spring back (with a programmable 'hold time' under pressure) and produces accurate formed parts. Strippit's patented Smart Stroke system maximises productivity by automatically calculating the optimum hover height for every stroke of the ram. The tool is kept close to the material on short table moves. As hits move farther apart, the software automatically increases the ram hover height to provide clearance for sheet warpage. The ST-1212 handles material thicknesses up to 6.3 mm and can take sheets of 1,250 by 1,250 mm. Hermitage punches mostly thin materials, stainless steel and aluminium from 0.5 to 1.6 mm, though occasionally will punch thicker workpieces up to 5.0 mm. In conclusion, Mr Spencer says: "We've reduced our set-up times and programming is far easier. The uptime on the machine is high, which helps us get more production through. The machine has speeded up our entire fabrication process. "The last six months has been a case of 'how quick can you do it?' You have to turn a job around quickly, and you must, must, must meet the delivery date. If you're not going to meet the delivery date, then you won't get the work." Elsewhere, at sub-contractor Washington Metalworks, Tyne & Wear, two Trumpf (01582 725335) TruLaser 5030 high specification CNC laser profiling centres with TruFlow 5000 (5 kW) resonators and integrated automation have been installed. Image: Washington's Trumpf installation Representing the first Trumpf installation of its kind in the UK, Washington Metalworks has replaced less powerful, older technology to quadruple productivity. Three 10-year-old manually-loaded laser cutters (1.5kW, 2.5kW, 3.5kW) have been replaced with two TruLaser 5030 automated models, the first Trumpf technology on site. The machines are linked to a LiftMaster Linear automated load/unload system and TruStore sheet storage unit. "We realised that, in order to move the business forward and compete, we had to invest," says joint managing director Steve Tate, who, along with business partner Ron Barella, provides the engineering expertise and business management that have underpinned the business since its inception 25 years ago. The £7.5 million turnover company supplies numerous industries that include railway, yellow goods, automotive and power generation. "Although we selected powerful machines, it was the speed of the technology in cut that provided the differentiating factor," says Mr Tate. "For instance, one particular job that previously took 1 hour 28 minutes to complete can now be done in just 23 minutes – a productivity increase of around 400 per cent. What's more, we had many recommendations from within the industry regarding Trumpf technology, while Trumpf also provided an uptime guarantee that other vendors were unable or unwilling to match." First published in Machinery, February 2010