Based at Ludvika, 150km northwest of Stockholm, Essverk AB builds bespoke excavation equipment used by road and tunnel construction companies.

Up to the late 1970s, Essverk built mining equipment, until the geology that provided Sweden and its economy with seemingly inexhaustible mineral wealth conspired against it, forcing the country out of the global ore market. Mining went in search of lower costs and softer rocks. To survive, Essverk turned its hand to developing excavator equipment. Today, the company designs many of its products as bespoke solutions to its customers’ very specific demands.

Natural resources

During the Pleistocene epoch, huge glaciers inched their way across what we know today as Scandinavia, depressing the rock beneath and leaving thousands of surface lakes in their wake. In the north west, along its frontier with Norway, Sweden is bounded by the Kjölen Mountains. East of that range the topography descends slowly all the way south to the Gulf of Bothnia, where faulted lowlands are home to icy rivers that crash over precipitous waterfalls and into ancient lakes.

The country lies on a tectonic plate referred to by geologists as the Baltic Shield, made from the oldest rocks in the European continent, and up to 300km thick. Deep inside this cold heart of crystalline and metamorphic structures is an estimated 15% of the world’s uranium deposits.

Beneath silt left by the ice sheets the going gets tough, so most of the roads and tunnels built in Scandinavia require extensive excavation work. Construction firms in the region prefer to own rather than hire their own vehicles, and to keep costs down many demand excavator attachments that enable a single vehicle for multiple tasks.

Multi-tool

Essverk AB is best known for its Multivip ‘Rototilt’ device, an innovative piece of equipment that transforms all kinds of excavator and loader operations. With its ability to dig, tilt and rotate in a single movement, it converts excavators from simple diggers into versatile platforms for a wide range of attachments. The Rototilt enables work from a static position with great flexibly while tilting in two directions simultaneously; meaning the need for constant machine re-positioning is eliminated.

Demand for the Rototilt is high, so much so that Essverk recently had to re-think and reorganise its machining capacity.

“A few years ago we had our own machining capability, but the industry trend at the time was moving towards outsourcing and its apparent cost advantages, so we adopted the same strategy,” explains Bengt Ericsson, the company’s technical systems specialist. “However, in the past few years, Swedish subcontract machining companies have become extremely busy and the lead-times quoted have grown longer. In turn, our own lead-time had started to extend; a situation that was unacceptable.”

To bring machining back in house, Essverk began its search for a large horizontal machining centre suited to manufacturing small batches of prismatic parts with various drilled and pocketed features. Cost, size, reliability and support were all criteria thrown into the company’s evaluation of options; the eventual conclusion was an EC1600CE CNC horizontal machining centre from Haas Automation.

“The specification, together with its performance and the price, represented the best business decision,” comments Mr Ericsson. “It was also available on a short lead-time, whereas other suppliers were quoting months.”

Installed in late 2007 by Haas Factory Outlet (HFO) Edströms Maskin, a company with 60 years experience supplying manufacturers in the region, the EC1600CE has already been put to work machining Rototilt components destined largely for Norwegian Nanset Standard AS, a distributor for Hitachi Construction Machinery.

Rototilt parts machined on the EC1600CE include housings (weighing up to 150kg), lower bodies, upper bodies and all internal components. In total, 55 different Rototilt parts are manufactured using the machining centre, making the most of the 22kW, 50-taper spindle and maximum speed of 6,000rpm. There are three different sizes of Rototilt, with components typically manufactured in sets using fixtures that are machined in-house. Each fixture presents two, three or four different parts to the cutting tool, ensuring maximum use of the 1626mm x 914mm table.

Cycle times vary between five minutes for the smallest and simplest part, up to two hours for the largest housing. All components are manufactured from various grades of engineering steel; tolerances are surprisingly tight, ±0.01mm in some instances, particularly for parts with bearing surfaces.

Despite the high demands, the Haas EC1600CE has coped admirably, as Mr Ericsson confirms: “Since installation we’ve had no rejects whatsoever. Off-line programming is straightforward using intuitive commands and both of our trained operators enjoy using the machine.”

The company has since ordered a Haas SL-30 CNC lathe, which sits alongside the EC1600CE at Essverk’s factory.

“The new Haas machines have helped reduce our lead-times and get production back on track,” Mr Ericsson continues. “At present, the EC1600CE is running eight hours a day, but this will be improved shortly once we have finished manufacturing a range of welded fixtures that will help reduce set-up time. We also intend to undertake subcontract machining for local companies. Eventually the machines will be running 16 hours a day.”

Epilogue

Given the country’s vast reserves, it was once inconceivable that Sweden’s mines would ever close. But eventually they did, as cheaper, more accessible ore became available to the world’s metal smelters. Companies supplying the country’s mining industry had to adapt to survive. Many didn’t.

As well as Uranium, archeologists believe that the country’s ancient rocks also hide the world’s largest reserves of gold and diamond. Mining its own reserves of talent and ingenuity, at least one tenacious equipment supplier will be around for Sweden’s next mining boom.