Market for clamping micro-workpieces grows bigger
Research hits smaller realms, leaving work for suppliers
University research has moved on from the micro to the nano area. Larger projects, certainly, are not expected. According to Baur, “Now it’s up to the manufacturers with their development departments.” Out of special solutions, series have developed, and building sets are being extended. Röhm, for example, has introduced a solution for the two-sided processing of a printed circuit board in one clamping. Baur said he expects a surge in development, especially for the combination of micro-clamping technology and automation. “Fast-change systems with high clamping repetition accuracies will play an important role.”
Generally, manufacturers of clamping systems are taking orientation from complete processing. Rolf Glück, sales manager of reference systems at Hirschmann, Fluor-Winzeln, Germany, cited the critical factor: “In practice, the start-to-finish process chain has priority.” Hirschmann applied the experience gathered from the alliance project Mikro Pro Ket and developed, with the µ-Pris Fix integrative neutral point clamping system, a mini-clamping system for applications in small component processing. Here, the change-accuracy in the process, i.e., in the change from one machine to another, is quoted at better than 1µm. This patented system is reportedly employed both for the cutting and non-cutting processing of workpieces as well as in measuring technology.
There is bound to be ongoing interest in further developments in this market. Since constantly smaller workpieces have to processed, tool and clamping equipment manufacturers have followed the same path of miniaturisation. Erowa’s Meier noted that “Ultra-small machines are conceivable, with very confined space inside.”
New materials and coatings expand clamping alternatives
Large amounts of development time and effort would have been saved if the dimensions of clamping devices could simply be made smaller. This is, to an extent, possible with conventional requirements. The processing of gold is another matter, not just because of the price of the working material. “The sometimes very aggressive cooling lubricants require a special construction,” Baur explained. Available from Röhm are therefore versions with chemically nickel-plated elements – versions which are not needed in conventional machining.
Besides the different working materials used in micro or macro clamping technology, it is above all the processing of the miniature clamping elements which call for know-how of its own. Jaw guides, for example, are ground with high precision using special methods for perfect fitting. “With such clamping, our procedures are a touch different from those of conventional chucks,” Baur explained. Developing a centric clamping system with jaws, for example, is a solution that at first sight, and with practical experience with a 3-jaw chuck in mind, should not work. But it does, as practice proves, and with high accuracy. After all, the wedding rings which are processed in a clamping system of this kind have to hold for a lifetime.
This article originally appeared in our sister magazine MM Maschinenmarkt and was written by Bernhard Foitzik.