Cable cars and ski lifts carry thousands of people up to the summits or back and forth between the ski resorts day in day out; mainly during wintertime. Here, passenger security has top priority. Therefore, the production of all cable car parts depends on maximum precision down to the hundredth millimeter range. The drive pulleys which move the cable between the top and bottom stations are huge and their center parts alone weigh just under two tons. This central piece is surrounded by four wing elements.
Unconditional precision is required for the manufacture of these parts so that the adapter plates of the wing element can be connected with the center part seamlessly. In the case of a pulley with a diameter of five to seven meters, precision means that the working surfaces may only deviate from the ideal shape by a maximum of 50 micrometers. If the distance between them is any greater, the wing element can no longer close. These very low deviation tolerances demand comprehensive and extremely reliable quality assurance.
A bridge-type measuring machine from Carl Zeiss helps cable car manufacturer Doppelmayr to ensure the quality of its systems. The machine scans the center part of the pulley in one full CNC run. It compares actual and target states, detecting every tiny deviation in the process. The results of the measurement can be retrieved at the touch of a button.
Thus, the quality assurance process can be carried out much quicker. In the past, quality was inspected literally by hand: a specialist would measure all relevant parts of each individual component using a measuring arm. With this measuring machine, the process is not only shorter, it is also four to five times more precise. In this way, the cable car manufacturer can guarantee the safety of passengers – and they can concentrate on enjoying the view of the mountain from the cable car as they make their way to the summit.
October 30, 2012