The Welsh firm Groundhog (UK) (www.groundhog.co.uk) manufactures Health and Safety Executive-compliant ‘welfare units’ in which staff working on construction projects, railways and other sites can wash, change their clothes and eat. The company was one of the first to introduce mobile facilities so that contractors can avoid the costs of transporting and installing static welfare units.

The idea proved highly successful; today, 30 years since Groundhog was formed, business is booming. The size of its factory in Neath was increased from 20,000 to 50,00sq ft in 2007, and a new machine shop twice that size is currently being built.

The production of mobile welfare units has doubled over the past few years to 20 per week, while static units have risen from two to five per week. Highly productive machine tools are needed to support such rapid increases in throughput, together with the use of automation where appropriate.

The latest example of investment by Groundhog in new production plant was the installation in June this year of a 3kW BySprint 3015 fibre laser cutting machine equipped with a ByTrans 3015 Extended 12-shelf system for the automated handling and storage of sheet metal. This joined an automated turret punch press installed in 2010 and took over from a Bystronic CO2 laser cutting machine with manual sheet loading and unloading that had been in use since 2006.

Matthew Stevenson, Groundhog’s design manager, said: “The combination of the manually loaded CO2 laser cutter and our automated punch press could not cope with the doubling of production volumes, even with the latter running ‘lights out’; the benefit of round-the-clock operation was apparent.

“There is not enough space in our current factory for two laser machines, so we decided to replace the CO2 model with the Bystronic fibre laser. The chiller and other peripherals are compact, and the machine is equipped with the manufacturer’s ByTrans automation system, which actually takes up less space than the previous laser machine’s manual loading area. Not only does the cell operate 24hr a day — unmanned after the 8am to 4.30pm day shift — but it also laser-cuts 1.5mm-thick mild-steel sheet three-times faster and with greater consistency than our old CO2 laser, which was of the same power.

“We are now cutting at 18 rather than 6m/min, profiling the sides, roof, doors and other parts of our products. Combining high processing speed with low idle times for sheet exchange has dramatically raised the throughput
of our welfare-unit components.”



A feature of Bystronic’s Bysoft 7 control software is its ability to tag components automatically during overnight running of the fibre laser, so that they remain joined to the skeleton by thin strips of material. During the day shift, when an operator is in attendance to keep an eye on production, tagging is unnecessary, as slippage of a component through an aperture to the underside of the sheet can be detected visually. During unmanned production, the addition of small tags ensures that unscheduled stoppages and lost production are avoided. It is an easy job to remove the tags when shaking parts from the machined sheets in the morning.

David Larcombe, managing director of Bystronic UK (www.bystronic.co.uk), says: “Customers see a real benefit in being able to add or remove tags on the machine at the press of a button. Typically, tagging can be quickly done when an operator leaves a machine for unattended running. The operator only has to set the minimum size of component to which tags should be applied to stop them tipping, and the process is carried out by the control; larger parts are left untagged for easy
removal.”

Highlighting the advantages of fibre laser cutting over CO2 technology, Mr Stevenson says that the significantly lower power consumption saves running costs, and no costly consumable gases are needed. He also says that maintenance is simpler — providing further economies — and that the quality of cut is better. Dimensional accuracy is within ±0.05mm, ensuring trouble-free bending and assembly of products. Furthermore, the fact that no burrs are left on the material surface eliminates the need to fettle components by hand, which can spoil their appearance.

While there is a three-fold speed advantage when cutting thinner materials, which is important as 1.5mm gauge accounts for 60% of the 100 tonnes of steel processed by Groundhog per month, thicker metals can be cut efficiently as well. For example, steel up to 15mm thick has been through the BySprint Fiber, as has 8mm 310 stainless steel and 10mm aluminium. Mr Stevenson says that this thickness of aluminium is five-times more than can be cut by a CO2 laser — and the quality of the fibre-lasered edge is markedly superior. Previously, thicker reflective materials were guillotined on site if straight edges were needed — or sent out to a water-jet cutting specialist for profiling, at extra expense.

Groundhog also relies on the accuracy of Bystronic press brakes to bend the laser-cut sheets. Two early models of 3m- and 4m-capacity date back to the period before Bystronic bought Edwards Pearson. The most recent machine is a 2.5m-capacity Xpert press brake; an order has been placed for an Xpert 40, Bystronic’s latest model launched at Blech 2014.