CNC punch press eliminates drilled holes

The installation of the latest CNC turret punch press has allowed holes to be accurately punched out in process, rather than drilled on assembly.

At Portasilo in York, the installation of the latest LVD Global 20 turret punch press from LVD (UK) of Marlow has allowed holes to be accurately punched out in process, rather than drilled on assembly.

The machine has also demonstrated how it can produce sheet metal parts in half the time of a previous generation turret punch press, while being far more accurate, with reject and scrap levels reduced by a third, and it is far quicker to set up.

When the previous punching and final drilling on assembly to ensure components are fitted together properly is put into context, there can be up to 500 holes required on some of the communication shelters and cabinets.

These critical position holes are now punched out on the Global 20 in under three minutes allowing assembly to be completed without any fitting.

Manufacturing bulk handling storage systems and a wide range of enclosures, panels and brackets for the communications sector; Portasilo has to produce a wide variety of sheet metal components.

So when the time came to replace one of its ageing CNC punch presses, the Huntington York-based company drew up a short list of the three most suitable machines on the market.

After detailed analysis, the management team decided that the new LVD Global 20 turret punch press, best met its all-round production requirements leading to its installation in June 2001.

This advanced CNC punch press has made a big impact on efficiency and is installed in a three machine cell along with a press brake and a folding machine.

As a result Portasilo has now adopted a cellular manufacturing concept and is able to economically produce much smaller batches and 'kits' of parts for a number of communications-related projects which was not really practical before due to the length of set-up and capability of the machinery.

As Production Engineering Manager Alan Harver explained: "Our oldest CNC punch press was proving increasingly unreliable, it was relatively slow by today's standards and its maintenance costs were spiralling.

We opted for the Global 20 on the grounds of its performance, speed, and cost, while tooling compatibility was an added benefit.

The Global 20 also allows us to punch in process the large numbers of holes in the various communication shelters and cabinets which is a massive saving in manpower and time." Portasilo is split into two divisions: Bulk Handling Systems, which supplies storage and handling solutions throughout the process industry; and Portastor Communications, which provides high security shelters, enclosures and masts alongside facilities management services to the communications industry.

Around 85 per cent of the work produced on the Global 20 is for the communications market which mainly includes meter cabinets, microcellular units and repeaters while the various shelters house communications equipment and switch gear, UPS, security and environmental equipment.

These projects involve the manufacture of a wide range of sheet metal components such as panels, doors, brackets, enclosures, cabinets and shelter elements in sizes from 152mm (squared) up to 1200mm by 2000mm.

From single batch quantities upwards, materials processed include: mild steel, plastics coated steel, stainless steel and aluminium to average tolerances of +/-0.01mm.

Most punched parts have to be formed on the press brake in the cell.

Based on a bridge frame construction which gives the machine a high rigidity, the LVD/Strippit Global 20 has a fully programmable hydraulic ram, a 200kN punching force with a 30-station turret which can index in less than one second.

It has a maximum nibbling rate of 800 strokes/min, axis positioning speeds of 110m/min and can process workpieces up to 2500mm by 1250mm and 6mm thick, without repositioning.

The ability to expand tooling capacity up to 146 tools and auto-index to 32 tools through the multi-tool units were important features that helped influence the purchase decision.

Key to the high productivity capability of the Global 20 are features such as Smart StrokeTM - which automatically determines the hover height of the ram based on material thickness and the distance between holes.

As Portasilo has found this considerably speeds the punching cycle and is controlled by a GE Fanuc 180i PC-based system.

The machine specified by Portasilo has a thick turret and is equipped with standard tooling, due to the nature of the work involved.

While the Global 20 spends most if its time nibbling and punching, the company has occasionally used a Wilson Tool special Wheel Tool in order to carry out certain joggling operations on a number of components.

Summing up the benefits Alan Harver added: "We have been well-satisfied with the machine's performance along with the level of technical support and back-up from LVD and we reckon it will easily pay for itself inside 15 months.

It is certainly fast, accurate and reliable and has been key in enabling us to optimise production efficiency on a whole spread of communications type work.

We have also been able to develop a number of new products, due to its capability.

So it has made a valuable contribution to the business.".

Back to top