Putting products to the test
Before they reach the market, all products and individual components undergo rigorous and extensive testing. STIHL strives for testing that is comprehensive and rigorous. The STIHL name has stood for top quality for almost 100 years. Whether chainsaws, clearing saws, leaf blowers, or lawn mowers – before the products are launched on the market, they are put through their paces.
CRASH TEST FOR GARDEN TOOLS
Garden and landscape maintenance equipment must withstand tough daily conditions.
At STIHL, all devices undergo a drop test. “One aspect of STIHL quality is that all the tools are robust, regardless of the type of drive,” says Alexander Härtel.
In addition, STIHL’s in-house tests consistently exceed standard requirements. One example: Blowers are not only dropped from the mandatory four positions, but from at least eight, with the exact number depending on their weight and size.
Furthermore, according to internal standards, a STIHL tool must not only remain intact after passing the drop test but also fully functional. The primary requirement is that users are not put at risk by broken plastic housings, exposed components, or the like.
PERSEVERING IN ENDURANCE RUNS
“Six seconds of idling, six seconds of acceleration up to maximum speed, then six seconds of idling again – repeated over and over again,” says Christina Escher, describing one of the endurance bench tests.
STIHL machines often spend several hundred hours on these test benches. The frequent transition between idling and maximum speed is a defining feature of forestry applications using gasoline clearing saws, such as Christmas tree harvesting.
The test bench measurement data gives Escher valuable insights into how the engine withstands continuous stress and how vibrations affect the entire device.
Even in the early development stages, tests are carried out on the numerous individual components that make up a new clearing saw. “Click, click, click,” echoes from the switching cycle test bench as the switches on the control handle are pressed repeatedly in a fully automated, computer-controlled process that replicates how the saws are used during the Christmas tree harvest.
FLYING LINE
The mowing line of a clearing saw is only a few millimeters thick, but it does an amazing job. As soon as the engine is started, the centrifugal force pulls the line outwards. At several thousand revolutions per minute, it generates enough energy to cleanly cut through blades of grass and herbaceous stems.
On the mowing head test bench, however, the nylon line meets a tougher opponent: a two-centimeter-thick bar made of solid beech wood. “This is a particularly good example of STIHL quality,” explains Simon Haug, pointing to the fine shavings flying around the test cabin. “In the test, our mowing lines cut notches up to ten millimeters deep into the wood.” This remarkable figure clearly showcases the quality and durability requirements of the mowing line.
IN IT FOR THE LONG HAUL
The three lawn mowers make their lonely circles. Covering almost 38 meters on each lap, by the end of the test they have traveled several thousand kilometers. The mowers go clockwise for half of the route, and counterclockwise for the other half. Sometimes they are fast, sometimes slow. Sometimes the blade is switched on, sometimes it is off.
At the beginning, the mowers actually did their rounds on grass, says Bernhard Huber. But the test areas couldn’t withstand this for long, especially as the tests became longer and longer. Instead of operating in the mud, the lawn mowers now rotate on a concrete slab at the STIHL Tirol plant in Langkampfen – 24 hours a day, seven days a week, in pouring rain or sweltering heat. On each lap, the mowers drive over a checker plate and steel bars of different heights, which cause the entire machine to vibrate.
QUIET, PLEASE!
Absolute silence reigns in the anechoic chamber. More than 1,000 foam wedges on the walls absorb every sound. Huber describes the experience of hearing nothing but his own breath as quite surreal.
He places the lawn mower in the middle of the room. Six microphones are arranged in a hemispherical formation, capturing every sound emitted by the device during the sound pressure level measurement.
To conduct this measurement, the mower runs at maximum speed for one minute. “An electric motor is naturally quieter than a combustion engine,” says Huber, adding: “The rotating blade is the primary source of noise emission in electric-powered devices.”
Spinning at nearly 3,000 revolutions per minute, it disturbs the air in a way that the human ear perceives as noise. When developing new lawn mower models, STIHL consistently aims to strike the ideal balance between optimal cutting performance and minimal noise levels.
ROLLERCOASTER RIDE FOR BATTERIES
The concrete mixer, in which Ioannis Hegny tests all the battery packs in the STIHL range, lasts about a year. It’s a commercially available model from the DIY store: “We replace the drivers in the drum to ensure that the batteries properly collide with one another,” he explains.
Three batteries tumble around the mixer for two hours at a time. The high-speed ride ages the packs quickly. When taken out of the mixer, they look as if they have been in use for several years. That would typically involve use across various devices, transportation in dusty toolboxes, and unsecured travel on the back of a flatbed truck.
According to the statutory standard, the housing only needs to remain intact enough to prevent fingers from getting trapped. The internal STIHL standard also mandates that after the drum test, the battery pack must be able to start a device, the contacts must function properly, and the LED indicators must light up.
For more exciting glimpses behind the scenes and insights into work at STIHL, visit the STIHL YouTube channel.
