Robot polishes and sands Viking skate tubesPrint this page
Viking Schaatsenfabriek in Almere uses a Nachi robot to polish and sand skate tubes. The robot imitates the manual polishing movement of the professional. Four years ago, the break-through of the clapskates meant the start of a new ice age for Viking. Director Jaap Havekotte: ''After the world cup competition in '97, all top skaters called us. The production could not keep pace. In spite of the fact that a robot can never imitate the feeling of a professional, we saw an opportunity to automate our production in an innovative way. Valk Welding from Alblasserdam joined us as robot integrator''.
A skate tube consists of a round bent plate, in between which a metal strip is being spot welded. The robot must be able to sand visible spot weldings and to polish the model. Starting point for the movement of the polishing robot is the imitation of the manual movement of the skate tube against the sanding belt and the polishing stone. The professional can correct this movement whenever necessary, the robot cannot. The problem we were facing was how can the robot see whether the tolerances are reached? Technical manager Simon Jan Vos: ''At first, we took polishing in the rotation direction of the belt as a starting point. Therefore, we had to repeat the movement three times in various steps. Later, we let the robot move the skate tube against the rotation direction. The result was a more even sanding of the material and a nicer polished look. This cannot be done manually, because no constant pressure can be exercised on the product because of the resistance.''
The robot is provided with a pneumatic gripper. The other components of the cell are two trays for product loading, a measurement unit for length and height and a complete CE-safety. The Nachi robot has a range of 2 m. Simon Jan Vos: ''The cell is composed of standard components, whereby the robot is imitating the human actions. For this project, the Nachi is a perfect robot, among others due to its user-friendly interface, with which you can feed in all directions up to 0.01 mm. That is exactly what we need to compensate the wearing of the polishing stone.''Each of the skate tubes is taken from the trays with a pneumatic gripper and guided along a number of positioning points. Then follows the side sanding along a belt sanding machine and finally the square polishing along a polishing stone. With the detection mould, the robot recognises which tube length has to be machined.
The production of the clapskate is mainly manual work. Simon Jan Vos: ''The robot has mainly taken over the polishing and sanding of the skate tube, whereby the production of the robot now equals manual production The most important advantage is that our professionals can now focus on other less monotonous work. Beside the cell, the polishers also operate other machines, such as the straightening and spot welding machines, resulting in increased production. Moreover, the end result is more constant than before. In the meantime, Viking is designing a clapskate with double hinge: another innovation that will further strengthen Viking's competitive edge. Jaap Havekotte: 'Investing in a robot also resulted from our innovative approach. Contrary to many multi spot welding machines, the robot can flexibly be fitted in into the production process, also whenever it would seem necessary in a later stage to switch to a totally different product.''
(Source: various professional magazines September 2001)