Perfect cooperation at every level

Since the company was founded over 90 years ago by Andreas Stihl, STIHL has been one of the market and technology leaders in the power tool sector. The long-established company in Waiblingen, Germany, develops, manufactures and sells motorized equipment for garden and landscape maintenance, agriculture, forestry and construction. Their portfolio includes chainsaws and power tools such as brush cutters, leaf blowers, shredders and grass trimmers. “The family-run and traditional company with a high equity ratio has brought us to where we are today - the same recipe for success as JUNKER,” says Kurt Schober, production planner at STIHL.

STIHL relies on the performance, quality and reliability for its products - and the JUNKER grinding machines used for the  complete grinding of the 1-cylinder crankshafts in STIHL power tools meet these requirements. The business relationship between the companies dates back to 2007, when the first JUNKER grinding machines were delivered. Since then, they have been producing reliably for over 17 years.

Various factors played an important role in STIHL‘s decision to purchase additional JUNKER grinding machines - including the compact design of the EJ 11 grinding machine, which ensures ideal optimization of the footprint. The production staff‘s desire for optimal accessibility to the grinding machines and the resulting convenience for servicing and maintenance proved to be a major advantage. Another factor is the well-known and innovative technology, as well as the high quality and short cycle times that STIHL can achieve with the grinding machines. „With the new machine project, it just felt right and there was a certain familiarity - that was a a key factor in the decisionmaking process.” explains Kurt Schober. 

Since STIHL already has JUNKER machines in operation, the technology is well - known to the team. Familiar production resources and tools, such as clamping devices, can be used to the greatest possible extent, which is a cost advantage by eliminating the need for duplicate inventories. In addition to the technical and economic benefits, an open communication, constant commitment and the realization of special requests played a major role in the purchase decision. Kurt Schober confirms: “JUNKER as a general supplier is simply excellent, something we could clearly see from the manpower and skills of the project team“.

The two EJ 11 grinding machines with automated loading and unloading, have been in operation at the Waiblingen site since 2024 and are an ideal addition to the production line. To ensure quality, workpieces are transported via a robot in the automation cell to the pre-measuring station, where their length dimensions are determined prior to grinding. The measured values are then transmitted to the two JUNKER grinding machines, allowing for automatic correction of the Zaxis longitudinal position. For STIHL, the length measurement is the most important measurement for the grinding process to ensure that the position of the crankshaft matches the cylinder. After determining the length dimensions, the two EJ 11 grinding machines are used for the complete grinding process of the 1-cylinder crankshafts.

A second robot picks up the blank part using the skip function and feeds it to the first grinding machine, on which the flat surfaces, diameters and recesses are ground. Following this, and due to the fully automatic transfer of the workpiece to the second grinding machine, flat surfaces, diameters and tapers are ground on the opposite side of the workpiece. After the grinding process, the robot cell takes over the brushing and deburring of the 1-cylinder crankshafts. “With the new machine, we can produce between 3,000 and 3,500 1-cylinder crankshafts in a three-shift operation, depending on the workpiece type,” explains Kurt Schober.

The two EJ 11 grinding machines - an economical and reliable solution for the precise production of a wide range of 1-cylinder crankshafts.