FlexiSTAT – Production Flexibility and Efficiency Through Simultaneous Three Axis Turning

In the manufacturing of industrial parts, turning is one of the most important processes besides milling and drilling. More than 35 % of all cutting machines in the SME industry are turning machines because turning is simple and flexible. Therefore, SMEs are able to produce a huge range of flexible products with only one turning machine. However, the major problem in turning is that high flexibility can only be reached by frequent tool holder changes. Due to the geometrical limitations in turning for every variation of the work piece shape a tool holder change is necessary - an important weakness that needs to be abolished.

The project ”FlexiSTAT” saw the development of the technology of simultaneous three axis turning as a modification of conventional turning where the tool is moved in a third rotational (B) axis besides the already existing translational (X, Z) axes. This additional movement is realized by the integration of the pre-existing but yet unused B-axis of turn-/mill or mill-/turn centers into the turning process. This has the following advantages:

  • The technology is applicable to almost all SME shop-floors and to already available machines
  • Low investment costs are necessary due to the use of already available machines.

To make the technology of simultaneous three axis turning applicable to the SME shop-floor, R&D activities in three different fields were performed:

Process Planning
Development of a CAM (Computer Aided Manufacturing) system which allows to activate and to control the additional axis efficiently and without collision.

Development of models, rules and methods to design the three axis turning process for arbitrary workpieces in an efficient and optimal way.

Development of tool inserts, tool holders and tool measurement systems which improve the efficiency of simultaneous three axis turning.

During the project, all developments were integrated in one machine tool to realize simultaneous three axis turning. Besides that, the technology was benchmarked in view of its economic benefits which include the following aspects:

  • Significantly increased flexibility due to an additional, fully controlled tool movement axis
  • Reduced tool consumption (-50%) because the applied tools can be used more efficiently
  • Reduced amount of tool holders in stock
  • Lower costs due to reduced tool consumption (-50%)
  • Reduced waste and reduced consumption of rare resources
  • Shorter production time, unproductive tool and tool holder changes are reduced (-20%)

FlexiSTAT is a research project founded by the European Commission (FP7, Research for Benefit of SMEs, PID:605717) with the aims to integrate the yet idle swivel axis (b-axis) in turn-/mill-centers in turning operations and to reduce the necessity of tool and tool holder changes significantly.