In athletics, some disciplines are difficult to follow for spectators. For football, it is clear to see when the ball is in the goal. In long jump, however, it is it is not easy to judge whether the last jump has set a new record. Virtual lines help the TV audience but they are not visible to spectators in the stadium. The PrimeLine system, developed by Golden Fly Sports GmbH, solves this problem by projecting the ‘mark to jump’ onto the sand.
The mobile installation was devised by Armin Margreiter, the former national coach of the Austrian long jump team, in cooperation with the laser projection specialist MediaLas. The system consists of three laser diodes, which are aimed at the pit and produce a visible line even in direct sunlight. The developers needed a drive unit that could move the lasers along a range of distances from 3 to 12 metres.
Long jumpers tend to kick up a lot of sand upon landing, which can bind with lubricants used in a conventional linear guide system causing it to stick. The development team had set the bar very high: all the components had to be robust and, above all, resistant to sand while being lightweight. Therefore, instead of traditional metal bearings, linear bearings made of the lubrication-free, high-performance polymer iglidur J200 from igus were selected. As the bearing remains dry, sand does not adhere and damage it. Its low coefficient of friction allows the precise positioning required by the IAAF, the International Association of Athletics Federation.
The drylin linear guide is corrosion resistant and maintenance free. It also has a long service life, which can be calculated online. As a result, it can be used continuously even during long competitions. Armin Margreiter is convinced by the quality of igus products: “The linear guides from igus have been in use on my systems for four years and they have never posed the slightest problem.”