# Feasibility Study of Integrated Precision Abrasive Machining of Shaped Surfaces
## 1 Introduction  
In finishing processes for curved surfaces (free form), there is often a need for sequential machining [1], consisting of pre-grinding, in which a homogeneous geometric structure is shaped after milling, and subsequent finishing, i.e., abrasive honing on the example of car matrices [2] or the manufacture of crankshafts [3]. For this purpose, it is necessary not only to change machining parameters [4, 5], but also to use tools with technical characteristics that are adapted to these treatments (type and size of abrasive grains [6], type of bond [7], structure [8], hardness [9], susceptibility [10], and elasticity [11]). Changing abrasive tools increases the time of the machining operation and requires changing their technological base, such as in the case of machining carried out on a CNC machining center [12] or an industrial robot [13]. Therefore, various types of tool warehouses are used, which are equipped with automated tool changers, for example, turrets with turning and rotary tools [14], or milling machines with grinding tools [15]. However, such solutions require their integration into the technical structure of a given machine tool and integration with its control system. Such solutions therefore have a narrow range of application, making their implementation costly and not very versatile. To shorten the production process chain, various optimization methods are used, such as the use of hybrid and integrated machining (also called sequential or complete machining). In hybrid manufacturing processes, different energy sources or forms of energy are used at the same time and in the same machining zone. Process combinations are used tosignificantly increase the advantages and minimize the potential disadvantages found in the individual techniques [16]. The goal of hybrid manufacturing is the \"\(1+1=3\)\" effect, meaning that the positive effect of a hybrid process is more than double the benefits of individual processes [17]. Integrated machining integrates more than one machining into a single fixture, so we can perform sequential (complete) machining. An example of the use of integrated machining is milling and grinding or turning and burnishing. For integrated machining, a device such as a lathe-milling-grinding machine can be used, and it is possible to integrate several operations on a lathe by using appropriate tools [18; 19]. Consequently, more and more CNC devices are appearing on the market, which enable several machining operations on a single machine tool and in a single workpiece clamping. An example of such a device is the DMG MORI Lasertec [20], which enables the integration of milling and laser surfacing [21; 22]. The use of CNC equipment that integrates several machining operations makes it possible to eliminate the downtime resulting from changeover, setup and the clamping of workpieces in several different machine tools. In addition, among such tools are toolholders that are mounted in the turret of a CNC lathe with a driven Y axis [23]. Such toolholders can be used for hole grinding and gear milling. Abrasive tools with retractable segments for finish grinding are also known in the literature, but they are designed only for flat surfaces and are not suitable for contour machining [24]. There are authors in the literature who are developing existing machining methods, such as using brushes to round off edges [25], are combining milling and grinding machining with Super Abrasive machining (SAM) [26; 27] through the use of innovative cooling methods during cavity dressing [28; 29], those who are changing the machining strategy [30], and authors who are improving the treated materials [31]. However, the presented examples found on the market and in the literature are few and far between, and many solutions are still missing to integrate more complex operations [16]. In particular, there is a lack of solutions for the integration of roughing and finishing in the grinding process of free surfaces.