# Obtaining Various Shapes of Machined Surface Using a Tool with a Multi-Insert Cutting Edge
## 3 Results and Discussion
### Universal Form Tool for Milling  
A universal shaped cutter prepared in accordance with the concept shown in Figure 1d is presented in Figures 5 and 6a. The tool, shown in Figure 5a, consists of a holder (1), sockets (2), and inserts (3) that are positioned in the sockets, arranged around the holder, and offset from each other. A clamping screw (4) fixes each insert in place. The inserts (3) are made with different outlines of the multi-insert tool to form specific contoured features on the work piece (5). Use of a  
Figure 4: Multi-edge form tool with single cutting edges: (**a**) examples of single edges of the multi-insert form tool (geometry of cutting edge for each part from left to right (axial feed): \(k_{r}=90^{\circ}\), \(k_{r}=45^{\circ}\), \(k_{r}=45^{\circ}\), \(k_{r}=45^{\circ}\), \(\epsilon_{r}=90^{\circ}\), \(k_{r}{}^{\prime\prime}=45^{\circ}\), \(r_{\epsilon}=5\) mm, and \(r_{\epsilon}=-5\) mm), (**b**) view of the virtual model of the tool, and (**c**) a sample object turned with the proposed multi-insert tool (CAD model and real object).  
cylindrical holder in the tool enables tool rotation [42]. Each single edge shapes a fraction of the surface, machining only one type of detail. An example is shown in Figure 5b of a machined surface with a multi-insert configuration.  
The main advantage of the multi-insert tool presented here is its capability to machine a large number of complex surface contours using only a limited number of single edges. A virtual model of the tool-work object interaction was prepared and is presented in Figure 5c.  
Changes in the cutting tool outline were achieved by adjusting the insert position of the cutting tool in the holder and its location. These features of the GKF milling cutter distinguish it from the conventional shape cutter that can only be used for obtaining one particular surface shape. Sometimes multi-edge tools are used with a single cutter; however, currently available solutions are not as universal as the GKF tool presented in this paper. The multi-insert tool prototype is shown in Figure 6a, while the examples of single edges are presented in Figure 6b. The design of this novel tool is patented [43].  
Single inserts were fitted into the sockets of the holder that permit radial distance adjustment for each edge individually. These single edges are made from cylindrical HSS. The rake angle and the clearance angles were set at \(\gamma_{0}\) = 0\({}^{\circ}\) and \(\alpha_{0}\) = 10\({}^{\circ}\)\(\pm\) 0.5, respectively. The value of the \(k_{r}\) area is also listed in Figure 6b. The body of the multi-insert cutter (Figure 6a) has 12 transverse holes that are radially spaced out at 45\({}^{\circ}\) with respect to each other. The distance along the axis of the main body between apertures spaced at 90\({}^{\circ}\) intervals is equal to the diameter of the hole, and the openings are offset at angles of 45\({}^{\circ}\) with respect to the preceding hole. All holes have diameters of 0.5.  
In the experiments, 12 wooden surfaces were machined using the universal form tool for milling to validate its performance, and the machined surfaces are shown in Figure 6c. A cutting speed of \(v_{c}\) = 150 m/min and a feed rate of \(f\) = 100 mm/min was used in the machining process. Employing a small number of single edges, we can achieve many other profiles by repositioning the single insert. In this case, the edges form a coverage area of the cutter that forms the contoured surface. Precise alignment of the characteristic points of the single edges common to neighboring edges is required for accurate machining results.  
Figure 5: Universal profile cutter with single inserts: **(a)** a sketch of the cutter [43], **(b)** an example of multi-insert configuration, and **(c)** virtual model of profile cutter in contact with the machined surface.