1,421 words
23 October 2002
Metalworking Production
English
(c) 2002 Miller Freeman

When capital is available, acquiring the ideal machine can present a dilemma. Take sheet metal company, Greenfield Engineering Ltd,which wanted something to make it stand out from other subcontractors. Two years ago, the Devon based company started researching methods for forming sheet metal; this led to the introduction of a Salvagnini Performer. Following its success, Greenfield travelled to Italy to view an S4P4 punch-shear-bend system. It's the first new generation Salvagnini punch shear machine to arrive in the UK since its launch at EMO 2001. Greenfield's new equipment now includes pressbrakes, automated turret punches and a laser, all supported by off-line programming.

After twelve months with the Performer, Greenfield's managing director, Frank Green comments: 'It was a gamble, but we have achieved 100% uptime and no problems with the machine. The quality of the products is very good.'

Greenfield's more recently introduced S4 has a patented head fitted with a series of independent hydraulic presses, each actuating a punch. Unlike a single-press head, the multi-press head means punching, notching and embossing can be performed in a single step with small movements. It also allows several simultaneous punch hits, creating upward embosses and machining that cannot be achieved on traditional turret presses.

'Salvagnini has good engineers that understand the machines and manufacturing processes, which is important. They help with the technical approach in introducing new technology into your factory and this support continues long after the machine is installed,' continues Green.

From Greenfield's perspective another plus point is the machine's capability to automatically feed and unload with blanks being moved to and from store if necessary. The stacker unloads the punched sheets onto several stacks either behind or next to one another. It is managed continuously rather than discretely, according to the dimensions of the parts.

Similar benefits were obtained at BSB Metal Spinnings Ltd. It purchased a Mazak NTX FMS laser machine to improve its competitiveness and enable it to respond to market conditions.

BSB immediately benefited from greater flexibility through the 6-shelf storage unit that accommodates 30tonnes of steel. Capable of processing random sheets to suit production, it can run a set amount of one batch and switch back and forth to suit production scheduling. This enables BSB to process 6 or 7 new jobs per day, up from 6 or 7 per month.

The Halifax based metal spinner produces industrial air conditioning units, light fittings, wheelchair brackets plus a subcontract fabricating service. Twelve years ago it noticed the decline of metal spinning and purchased its first punch press to diversify into new market places.

With aging punch presses it has struggled to compete for hard tooling projects, collecting maybe one order from ten. With its 10 week turnaround, being impractical for batch runs of up to 10,000.

The laser created new possibilities from its ability to manufacture parts within a 24-hour turnaround, ideal for prototype work. It also gave the company the ability to produce curves and geometries in sheets up to 12 to 13mm thick on its 2.5 by 1.25m bed, a major improvement on the 2 to 3mm capabilities of its punch presses.

Steffan Ltijens, technical manager comments: 'Its capacity allows us to switch the lights out on a Friday night and collect the completed parts on a Monday morning, giving us the ability to compete for large batch runs. It also improves our flexibility enabling us to process a host of different parts without interference.'

Clean cut

A high percentage of its parts are made from stainless steel, brush stainless and Zintec, none of which undergo painting or finishing. Without finishing the pressed parts have to follow the stringent process of deburring and cleaning, a process that can take two to three hours per part. The laser's advanced vibration damping analysis system has completely done away with burrs, significantly improving the finished quality. The FMS has reduced handling, a source of surface contamination. For this reason all expensive and high quality parts have been transferred from presses to the laser.

'Its amazing that in an engineering environment parts can be processed without handling. The machine eliminates manual loading/unloading, which is great as some parts take longer to remove fingerprints and marks than actual processing. The parts being taken from the machine can be shipped with confidence,' continues Litjens.

BSB had problems retaining skilled staff to run the laser. It had three people operating the 1.5kW machine on three - shifts. As workers gained familiarity, only one programmer was required with operators' loading sheets. Labour requirements have now been cut in the toolroom with five of its six toolmakers working in other departments following the reduced need for hard tooling.

It enables BSB to produce components without the excessive cost of tooling, allowing it to conduct extensive R&D work. This can be done quickly and efficiently with customers programs being converted to the laser from DXF files. 'All we have to do is fire a program down to the machine and within no time we can produce a component. The new machine has vastly improved operations giving us the confidence and ability to compete for projects that were previously beyond us,' concludes Litjens.

Another company pleased with the results of purchasing a laser is Blaze Neon, a manufacturer of illuminated signage. It purchased a Bystronic Bystar 4020 laser cutting centre supplied by Pullmax.

The company annually subcontracted out £250,000 of laser cutting work. In order to make the business more cost effective and efficient, deputy managing director Clive Knight looked at bringing the laser cutting in-house, commenting: 'As the laser cutting of aluminium has been perfected over the past few years, we believed it was time to invest in our own equipment, routing 6mm aluminium is a slow and expensive process. We looked at a number of machines and believed the Bystar was the most suitable.

'We felt it was a universal machine that could cater for all our cutting requirements and in particular the cutting of acrylic. Companies face stringent health and safety regulations when cutting acrylic and Bystronic has the necessary technology in place to ensure these are met.' Since bringing the work in-house Blaze Neon has increased capacity and reduced lead times by up to a week.

'Not only have we saved money by bringing the work in-house, we can also ensure the quality reaches our standards and meets our customers needs more effectively,' concludes Knight.

To ensure customers' expectations are met, Bystronic has launched a range of new products and innovations to enhance its range. Recent introductions include the Bytube and Byspeed machines and Bysoft 6.4 software.

The Byspeed laser cutting machine has been redesigned with a new compact frame that enables quicker installation. The cutting area is enclosed with a multi chamber vacuuming and self cleaning dust collector that incorporates a 4000W resonator with an oil free turbine and an axis acceleration of 30m/s for high positioning and cutting speeds. The improved Byspeed 3015 is capable of 600 holes per minute at 2mm diameter with accuracy increased from 0.1 to 0.05mm.

To enhance its machines Bystronic has developed the Bysoft 6.4 software package, which monitors tool collision, defines bending sequences and conducts part nesting for the arrangement of different parts. When used on the Bytube it automatically shows lead-ins and uses seem detection to reduce waste. It analyses contours and determines whether to pierce, pulse or cut.

This latest version uses the kinematics of the machine to follow contours. By following the fastest line and not the logical sequence, directional changes are reduced, minimising machine wear.

Reducing wear on machines has become a focal point at Bystronic. It has developed a new pump for its waterjet machines. The new pump has two pistons as opposed to four in many machines, cutting maintenance requirements. It also enables the machine to run without the need for a vessel after the intensifier to improve pressure control.

All elements in the pump and intensifier are electronically supervised. Error finding is simplified as the control shows the operator which element has a malfunction. The intensifier can be run by a laptop, without the machine being switched on. The new developments at Bystronic are designed to reduce maintenance costs and waste material - and improve machine efficiency.

Copyright: Centaur Communications Ltd. and licensors.