When it comes to machine tools, Andreas Jung, plant manager at Siegerland Bremsen, Haiger, Germany, is not so easy to fool. After all, in his “first working life,” which lasted 33 years, he was employed in several different roles at the machine tool manufacturer Waldrich Siegen. With that kind of experience, he certainly knows his machine tools.
And when someone like Mr. Jung has nothing but positive things to say about a machine, then that really means something. In this regard, we are talking about the EMCO VT 250 vertical lathe. Two of them are being used at Siegerland Bremsen where the company has turned the production of hydraulic components upside down, literally.
Siegerland Bremsen was founded in 1958 to machine nonstandardized drum brakes according to customer drawings. Five years later a new production plant was acquired, which already proved to be far too small another 5 years after that, making it necessary to expand the facilities.
In 1986, the company was purchased, and the production facilities were modernized. From 1988, all the investment went into CNC machines. The company also placed a strong focus on internationalization and now has branches in Spain, China (since 1999) and India, among other locations. The product range includes industrial brakes (drum and disc systems) for harbors, conveyor belts, steelworks, wind turbines, crane systems and, as a recent addition, wheelsets for industrial cranes.
According to Mr. Jung, there is an intentional rejection of standard management and production philosophies in this regard. “Unlike many other companies, we keep a very large parts stock. This enables us to both optimally design our part production processes and maintain an extremely high readiness to deliver. With our structures, that makes a great deal of sense.”
Almost all parts for all products are produced in the production plant in Haiger-Rodenbach, Germany, and then moved to the nearby assembly plant.
One of the workpieces with the highest production figures is a component for hydraulic systems, of which as many as 5,000 pieces per month are produced. The constantly increasing quantity made it necessary to completely rethink the previously used methods and resources. “As you’d expect, we looked at all options, from complete machining through a complex machine with a main and a counterspindle. including a robotics-based parts feed to two simple lathes,” Mr. Jung says.
“Initially, we favored a solution with two simple horizontal lathes, but then one employee suggested the use of vertical turning. I’d actually considered this technology before at one point, but the cost of those kinds of machines would simply have been too high for the machining work in question,” he continues.
“The main reason for this was that as a supplier, you predominantly have the ‘usual suspects’ within your sights, and it was only when we came upon EMCO’s name (and price list) during our research that our investigations into vertical lathes took on concrete form. It quickly became evident that when considering the parts geometry, the dimensions and the relatively high quantities, vertical turning was a far lower cost technology than a conventional solution with horizontal lathes,” Mr. Jung says.
In light of this, it was relatively easy to convince the management of how much sense this venture made, and they invested in an EMCO VT 250 relatively quickly. And it only took just over 5 weeks before Mr. Jung had to admit to the management that he had misjudged things when purchasing the machine.
“I told my manager that I’d made a mistake when purchasing the VT 250,” he says. “I shouldn’t have ordered only one machine; I should have ordered two straight-away. Not long after the VT 250 was first commissioned, it became clear that it instantly exceeded all of their expectations and that vertical turning certainly deserved all the early praise it had received.”
He continues, “The automated parts feed makes the machine so much easier to operate that it isn’t necessary for two employees to be involved, as with the horizontal solution. Instead, providing all the subsequent operations are also conducted on a vertical lathe, one machine worker is enough.”
The management also agreed with this observation, and the second VT 250 was ordered just a few weeks after the first. This was installed at an angle of 180 degrees to the first machine so that the two feed belts run parallel next to eachother.
Mr. Jung says, “By opting out of an automated solution, if lower parts quantities are required at any time, we can simply machine a different parts range on the second vertical machine without any need for conversion.” Enough potential parts have now been identified. “Once you’ve installed the vertical turning technology, you discover more and more potential uses for it.”
Following the installation of the second VT 250, Mr. Jung made his first assessment. He says the company halved the machining time, and therefore doubled the capacity. Also, the quantities have clearly increased since they ordered the first machine, meaning that the reduction in machining times has a very favorable effect.
“We’re still using two machines, but these have a far smaller footprint than the old solution, and we only need one employee rather than the previous two.” And these are not the only advantages.
Previously, Siegerland Bremsen was unable to create the desired finishes in-house and had to outsource the parts for finishing. Now, the company can use a tool-based solution in conjunction with the EMCO vertical lathes to achieve even better results than its former supplier. The parts come away from the machine pre-finished and go directly into assembly.