by Andrei Petrilin, Iscar technical manager
Manufacturing’s push towards comprehensive digitizing will impact almost all stages: product design, process planning, machining, assembly and logistics. The driving force behind the changes is a series of technological breakthroughs related to Industry 4.0.
With the use of network communication, new digital technologies combine physical manufacturing systems with the virtual world and 3D modelling. As manufacturing systems continuously improve their intellectual features and decision-making capabilities, they become more complicated and more expensive.
Minimizing the downtime of such systems is important for the development of every system component, such as machine tools, workholding devices or cutting tools. Cutting tools can not only cut metal but also cut downtime, depending on their design.
Assembled cutting tools with exchangeable cutting heads from cemented carbides are very common in metalworking today. Two decades ago there were very few systems built on an exchangeable head principle. Now practically every leading cutting tool manufacturer has this type of system in its product range.
Advances in tool grinding and resharpening machines have simplified production of solid carbide tools and their regrinding. This has increased the number of small and medium-sized tool manufacturers, and a growth of regrinding services. It might have been expected that the solid carbide design approach would seriously challenge the exchangeable alternative and quickly regain lost ground. However, this has not happened—indeed, the situation is reversed. Progress in machine tool engineering and the current trend towards smart manufacturing hold good promise for the future of assembled cutting tools with exchangeable heads.
An example of this contrast is cutting tool manufacturer ISCAR, which introduced the “no setup” principle in tools with exchangeable heads without removing a tool from the machine. The source of this “no setup” feature is high repeatability of the exchangeable heads that is ensured by a face contact between the head and a tool body, and strict tolerance limits for the head area protruding over the body. The “no setup” principle was successfully realized in Iscar’s Multi-Master and Sumocham rotating tool lines.
In non-rotating products, the new Multi-Grip and Logiq-5-Grip parting and grooving tools represent a different approach, where the assembled tool comprises a tool block and an indexable multi-pocket adapter carrying replaceable inserts. Due to the high precision of the assembly components, the pocket indexing does not require additional setup. Both “no setup” concepts provide significant reductions in machine downtime.
These tools also offer exceptional versatility. The Multi-Master is suitable for mounting in different tool bodies, and the body can carry different heads, enabling thousands of tool combinations for a broad range of applications including milling shoulders, faces, slots or complex surfaces and machining holes or chamfers.
Multi-F-Grip non-rotating tool blocks and four-pocket adapters integrate both Tang and Do-Grip inserts. Versatility was once considered the main advantage of tools with exchangeable heads. However, recent progress in machine tool engineering and the trend towards smart manufacturing based on Industry 4.0 concepts, “no setup” capabilities have reemerged.
Advanced regrinding now allows restoration of cutting geometry of a worn solid carbide tool with high accuracy. However, the tool changes dimensions slightly and putting it into operation demands preliminary setup and appropriate corrections in a CNC program. This causes a reduction in effective uptime, diminishing productivity and increasing production costs.
However, a “no setup” quick-change cutting head eliminates these supplemental measurements and corrections, and does not require any additional setup. This is why the “no setup” capability of a cutting tool plays a significant role in a smart metalworking factory. From this point of view, “no setup” assembled tools with exchangeable carbide heads, such as Multi-Master and Sumocham, are a good match for a smart factory. Understanding the benefits of this capability makes it clear why ISCAR considered tough tolerance limits for the overhang as an essential design requirement when the company started development of these two lines almost twenty years ago.
A further advantage of using tools with exchangeable heads is custom tool configuration according for machining a specific part. Machines that handle various types of cutting in one single-step process have become very popular. These machines have driven-tool capabilities for combining machining by rotating and non-rotating tools, which can significantly improve productivity. The power characteristics of a typical driven-tool unit are similar to the parameters of a typical small machining center. The Mulit-Master line features a wide variety of tool bodies (“shanks”) with different adaptations, reducers and extensions, which ensure an optimum configuration and minimize tool overhang, reducing the bending load on the driven tool unit mechanism to improve performance and tool life.