„If our product isn’t right, then we’ve got a huge problem on our hands”
Stadlbauer and his team rely on the ACCRETECH SURFCOM TOUCH 50 to measure ski profiles after production. The mobile roughness measuring instrument is used when a ski leaves one of the four grinders installed in Fischer’s production facility. These machines use a diamond to cut the special groove patterns into the grindstone, which then transfers them to the plastic surface of the ski.
“Once we have set the cut on the machine, we produce a test ski, which is then measured,” says Stadlbauer in explaining the procedure. “When we are within the permissible tolerance range with the measurement, we start grinding the skis.” Random samples are then taken to measure whether the surface roughness is OK or NOK . Fischer produces 100 to 200 skis per day in this way. 20 to 30 of these undergo random sampling.
“The number always varies somewhat,” says Stadlbauer. “There are cuts where you know that 50 skis can be produced without any problems. However, with other cuts, you need to check after 10 or 20 units.”
The measurement data obtained is stored and compared against each other. “This allows us to identify developments and assess whether we might have to change the stones or the diamond, for example,” says Stadlbauer. Here, it is good to be able to take a close look at the roughness curve.
From what experts tell us, setting the machine correctly is a challenge. There are many factors with the ability to influence the right cut. In addition to the stones and diamonds, the quality of the water that is used is one reason for this.
When Fischer tries out new profiles, they are initially cut on some skis. A test report is then created, before Stadlbauer and his team step onto the boards to test them. At the end of the day, they are all also passionate cross-country skiers. Using these tests, they then work towards the appropriate tolerance range for the roughness measurement.
The Ra-value, Ra-Max and Ra-Minimum as well as the Rz-value, Rz-Max and Rz-Minimum are relevant in this regard. “We look primarily at the Ra value and have a range of between 0.2 and 0.3 μm,” Stadlbauer adds. For example, it is then possible for a ski to have a cut with a Ra value of 2.2 to 2.4 μm.