Ski Production Line Gets a Lift
Since 1939, the Swiss company Montana has been supplying machines to ski service providers worldwide, enabling them to provide optimal support to winter sports enthusiasts. Montana has not only developed high-end ski treatment machines with different degrees of automation for ski rentals, but also, for instance, air-conditioned ski depot systems. With a new machine type design, Montana has now branched out to offer its innovative services for ski production.
The fully automatic sanding line presented here was developed from Montana machines for ski rentals and is designed for medium-sized batches. Montana’s long-standing chief designer Johannes Höfflin explains the machine concept: “Nowadays there is a very discerning clientele with special requirements – people will gladly pay 2,000 euros or even significantly more for a pair of skis. Our new machines facilitate ski production of small and medium batch sizes on an industrial scale and with industrial precision, specifically for this market.”
The control system of the sanding line provides suitable parameter sets for any type of ski. You can select the required parameters for the current ski type and start the machining process on the display. The procedure is always the same: Smoothing the coating, grinding in the required surface structure, sanding and polishing the edges, drying and waxing the ski. This fully automatic sanding line can process up to 30 pairs of skis. To date, the only manual steps were positioning the skis on the cross transport belt and removing the skis from the machine.
Johannes Höfflin remarks on the topic of machine line operation: “As serial ski production requires that the skis are stored between the individual processes in any case, we wondered whether these “buffers” could simultaneously be used for automatic feeding of skis into the sanding line. This led to the idea of a mobile paternoster lift as a ski carrier and intermediate storage system.”
Employees now have a convenient way to load and unload the mobile paternoster lifts on the upstream and downstream stations or work areas. Most notably, this method is independent from the timing and location of the sanding line and its cycle rate. The loaded paternoster lift is simply moved to the sanding line, aligned approximately and connected to the control system. “With this method, the mobile paternoster lift permits a significant increase of the main production time, the sanding line output and the overall ski production. Furthermore, linking different work stations becomes significantly easier,” Johannes Höfflin says, confident in the new system.
Two studded timing belts transport the skis from the paternoster lift into the sanding line. A second paternoster receives the skis in the same manner after machining.
Two endless joined BRECO® timing belts with welded profiles are used for transport on the paternoster. Engineer René Preßler of Mulco’s sales partner Hilger u. Kern based in Mannheim explains the project: “Basically, we had two options. Either we weld the profiles to the back of the belt or we use BRECO’s ATN system. The latter had a higher load bearing capacity, but requires double bolting for each individual profile. Montana decided on the welded variant.”
The solution for fitting and dismantling the ski carriers from the profiles is particularly elegant and practical: Spring-loaded balls lock the holding bolts in place axially, making bolting unnecessary and making it possible to replace the ski carriers without tools.
Many profiles are available
The timing belts and customer-specific profiles were manufactured and the profiles welded onto the belts directly at the premises of the manufacturer and Mulco member BRECO Antriebstechnik in Porta Westfalica. The profiles also consist of high-quality polyurethane.
A keyway and a drilled hole are sufficient for fastening the coated ski carriers to the profile. Although the load of the ski weight is relatively low, the belt requires a relatively strong tension for problem-free guiding of the skis. Bearing supports on both sides of the pulleys provide a stable support for the drive shaft and prevent excessive bending. A 24V motor with a worm gear unit is used for the drive. The self-locking mechanism of the worm gear unit ensures that the paternoster lift remains at a standstill when the motor is switched off.
The 24V DC voltage has several advantages. First of all, it reliably prevents danger to the operating staff, even in case of an electrical fault. Secondly, a 24 V battery permits mobile operation of the paternoster independently from the sanding line. This is a major simplification of ski handling and the manufacturer’s workflow and permits an ideal utilisation of the sanding line capacity.
Like BRECO, MULCO member TransDev also offer a wide range of profile shapes which can be adapted to their specific task through mechanical reworking (drilling and milling) and can offer customised profile shapes.