Details

December 2019

New project moves on the edge of the technically feasible

Normally, we at Hjerno develop and produce tools that typically weigh between 250 kilos and several tonnes. But once in a while we knock into a project that challenges us beyond the ordinary.

An ongoing project for a Danish customer is a good example of this. Here, Hjerno has to manufacture a four-cavity micro-tool of just over one kilo, capable of producing samples of just two millimetres and weighing 0.14 grams.

Thus, the tool must really be produced within the smallest tolerances where, among other things, special closure surfaces are included that must be offset by three microns in relation to the other closure surfaces.

“These are so infinitely small tolerances that we move at the edge of the technically feasible. And we are working in a level of precision that you would not think possible. I know very well that in the tool industry we have all gradually become accustomed to talking about precisions down to three microns, but having a real 100 percent control of three microns with ultra-small machining details, this is, after all, only mastered and guaranteed by the very few,” says Managing Director Aage Agergaard.

Experience and technology
This kind of precision work is made possible not only by investments in advanced machines and measuring equipment that can handle such small tolerances, but also by the company’s accumulated experience in dealing with such samples - not least in relation to optimal machining strategies and other process technical parameters.

This is an experience that has been built up, among other things, through a high-precision project on the development of tools for fuel cell production, and which is now applicable to extremely complicated tools.

“This built-up routine in ultra-high precision also means that all the tool parts, which we produce for our tools, become so precise in all parts, and not only in the moulding parts, that our tools last for much longer, as precise tool parts are not worn in the same way as parts with larger tolerances. Over the years, it has become something we just do because we have the necessary experience, knowledge and in-house technology,” says Aage Agergaard.

Time-consuming tasks
He calls this kind of ultra-precise tasks good training for Hjerno's skilled specialists, who get off on manufacturing very unique and complicated tools.

“But the tasks are also so complicated and time-consuming that we can only take in a few of these tasks each year. We are not doing this to make money here and now, but to raise the professional bar in the house,” concludes Aage Agergaard.