To evaluate the technical and economic impact of the results of flexiSTAT, a demonstrator part was manufactured and a corresponding case study was conducted. The defined demonstrator is a part from an SME end user to accelerate fluids. See the following figure:
Demonstrator part and corresponding process chain of manufacturing
The initial material was a round, saw cut part. In a first step, turning of the material was required. The turning process was divided into three machining processes: 1. the roughing, 2. the pre-finishing, and 3. the machining of the part by 5-axis milling after the turning operating. However, the milling was not considered during the case study. It has to be mentioned, though, that the milling process can also be performed on the same machine tool and in the same clamping as the turning process. The reason is that for simultaneous three axis turning, a turn-/mill- or mill-/turn-center is used. The following figure shows the final turned part:
Demonstrator which was manufactured by simultaneous three axis turning/FlexiSTAT technology.
A first technical evaluation has shown that by simultaneous three axis turning all requirements (form tolerance, surface quality etc.) could be met. It was also shown that all required form tolerances could be achieved. Moreover, the required surface qualities could be achieved by simultaneous three axis turning. Thus, simultaneous three axis turning is, from a technical point of view, a serious alternative to conventional two-axis turning. However, in order to also evaluate the economic impact of the developed technology, the working times and tool consumption was recorded during the machining of the demonstrator. In the following picture, the time and costs of roughing, pre-finishing and finishing of the demonstrator part are shown. Time and cost are separated in “machining related” (= pure cutting time/costs) and “tool related” (= tool insert costs, tool insert change, tool holder change, tool measurement time/costs).
It is evident that for all three machining steps the machining related times and costs are the same in two axis turning and in three axis turning. The reason for this is the fact that the cutting parameters (vc, ap, f) in both processes are the same. Therefore, the cutting time is also the same as well as the related costs. However, when focusing on the tool related times, it is shown that these can be decreased significantly. In all cases, the tool related times can be decreased by more than 50%. Due to this, the tool related costs can equally be decreased by more than 50%. As a result, in roughing, the total manufacturing time can be decreased by 16.1% and the costs by 25.1% when using simultaneous three axis turning. In pre-finishing and finishing, the manufacturing time is decreased by 10.9% and costs by 14.5%. The total times and costs which can be saved by means of simultaneous three axis turning are shown in the following figure:
Machining times and costs benefit from simultaneous three axis turning in comparison to conventional two axis turning.