From medical products and turbine blades to jewelry, microcutting has enjoyed an ever-growing body of applications. But what exactly is microcutting, and what does it require from your waterjet machine and your abrasives? GMA recently sat down with Ridder, a leading manufacturer of waterjet cutting systems, to discuss the present and future of microcutting.

Q. What is microcutting?

A. Microcutting is a special form of abrasive waterjet cutting that uses the smallest diameters to deliver high levels of precision, repeatability and system availability. In most cases, this involves manufacturing very small and filigree contours. However, microcutting isn’t only used to produce the smallest components and most complicated geometries. We also have customers who use microcutting to cut several thousand holes, each with a diameter of only a few tenths of a millimeter, in medium- or large-format sheets.

In 2003, we approached the subject of “small components” for the first time through a series of test cuts on dental implants made of metal. Although the component was still quite large—it had a length of approximately 10mm—the contour featured filigree with a maximum permissible deviation of 0.02mm. This was challenging but feasible. But at that time, nobody referred to this as “microcutting.”

Q. What is the smallest item you have cut? What is the smallest item being produced in the industry?

A. It’s difficult to identify the smallest waterjet component, as we don’t know all the things our customers are cutting in a given day. However, in sample productions, we have processed components sized at approximately 1m to 2mm. It’s also possible to cut boreholes that are about 0.2mm. For carbon components such as clock dials, you could see a very interesting microcutting combination: pre-drilling with a 0.2mm drill and cutting with a 0.2mm abrasive jet.

Q. What is a standard parameter for microcutting garnet consumption and cutting speed? How many items can you produce, for example, in one hour?

A. To calculate this, you would need to take a specific component, create a sample and use these values to check the production capacity. It’s also important to remember that microcutting is not limited to one cutting head. We have many customers who produce micro-components with two or more heads at the same time. The abrasive feed rate used in microcutting can also vary widely. We have manufactured components that were cut at a few grams per minute, all the way up to values of 40, 50 or 60 grams per minute. This can vary a lot depending on the application.

Q. Please share some popular items produced with microcutting.

A. Applications for microcutting are widespread. They range from medical products like implants, “bone saws” and long drilling shafts to small electrical contacts and fuel cell parts for e-mobility. Microcutting can also be used to produce watch components such as dials made of carbon; blank machining and other electronics; material samples such as tensile tests; turbine blades; precision mechanical tools for lock cylinder openers; sieve plates; jewelry and beyond.

There are also very interesting 3D processing applications that utilise microcutting. Small cooling holes in turbine combustion chambers are just one example.

Q. Do you need a specialised cutting machine to execute microcutting? What is an effective machine setting for this scale of cutting?

A. Microcutting has been a standard option for WARICUT systems for more than 10 years. Every WARICUT machine produced in the last three decades can be equipped with microcutting functions—regardless of whether it is a 2D, AB, 2.5D, 3D, 4000 or 6000bar. To date, the largest WARICUT system delivered with microcutting functions had a traverse range of 12x4m with two 3D cutting heads.
We also offer the WARICUT micro-max, a highly specialised machine for micro- and macro-processing. The micro-max delivers a positioning accuracy of less than 0.003mm and many other technical equipment options.

Q. Does microcutting require a specific type and quality of garnet?

A. For microcutting, the quality requirements for the abrasive are very high. Neat, continuous series production is only possible with consistently good material. The abrasive must be made perfectly from a good raw material, but there are other factors to consider as well. Details such as packing, storage and the degree of drying are very important.

For more than 20 years, Ridder has used various abrasive products from GMA for all our test cuts. From 50/50 mesh up to SuperFine, the consistent quality has impressed us. It’s very important for us to always achieve the same results, even if a cutting attempt is repeated a few years later. Besides the product quality, I value the professional, friendly collaboration we have experienced with GMA.

Q. What do you see on the horizon for microcutting? How will it evolve in the next five years?

A. Recent cutting tests have shown that there is even more demand for microcutting in the field of electromobility. From filigree copper plug contacts to bipolar plates for fuel cell production, new areas are emerging within the applications we know and use today.

ABOUT RIDDER

For three decades, H.G. Ridder Automatisierungs-GmbH has been synonymous with high-quality waterjet cutting systems. With the launch of its WARICUT line in 1991, the company became one of Germany’s first waterjet cutting systems providers. Ridder has led the field ever since.
Ridder’s specialised expertise in waterjet cutting systems evolved from its core business in machinery construction. Since the 1980s, the company has raised the benchmark for quality in the automation and overhaul of machine tools; the construction of special purpose machines, high-pressure cleaning systems and machining centers; and production line integration.