ATC Industry 4.0: basics of computer numerical control
The developments in the field of machine tools industry with computer numeric control (CNC) become more and more popular and advanced. From a conventional three-coordinate machine, we proceeded to creation of high-precision machines and machines with automatic tool change. Market demands require continuous improvement of the instrumental base and program management.
The computer numerical control (CNC) provides for automatic control of drives and machine units according to the loaded control program. Usually, control programs are written in a special programming language called G-code. This code is a sequence of commands to perform simple operations by the machine.
Automatic systems for technological preparation of production (ASTPP) or computer-aided manufacturing (CAM-systems) are used to develop a CNC control software according to ready-to-use 3D models.
These systems are intended for parts treatment process simulation on a PC. We use HSMXpress CAM-system in our work.
Blank parameters that is used to produce an item are specified initially during the simulation processing. The initial point to set the coordinate grid of the machinery is placed onto the blank. After this the operations to produce separate elements of the model, such as a groove, pocket, group of holes and others are to be developed. The tools and operating parameters of every operation are to be determined. Tools are chosen from a database which corresponds to the real tool set in the machinery basket. Fig.2 shows the tool set of ATC Industry 4.0 machinery.
The tool motion paths are generated after setting of all operations. CAM-system permits to simulate a blank machining and to compare the result with the original 3D model (see Fig.3).
On completion of the simulation program it is transformed into the CNC codes. This process is called postprocessing. The postprocessor takes into account the CNC features for a specific machine tool model.
It is necessary to set the tools into the machine which were chosen to produce the detail. As a rule, the machinery has certain tools suitable for manufacturing all details the product. The cutting modes depend on the blank material and determine quality of the surface to be obtained. Tools are stored in a basket and are automatically set into the machinery spindle in accordance with the loaded program. Every tool must be calibrated in the Z coordinate relatively to the common check point.
The blank is installed into the clutches or other fixing device mounted on the table surface. The table moves the blank in the XY plane. The blank position should be bound with the machinery coordinates system and the checkpoint that was chosen in the CAM-system in order to set the correspondence between the machinery coordinates system and the checkpoint. The special instrument called 3D indicator is used to precise the binding. It allows of determining the blank position with accuracy of 0.01 mm in the machinery coordinate system.
Use of the machine with an auto-change tool ATC Industry 4.0 (see Fig.4) for creating a product prototype or the finished product is greatly simplified, and manual labor is also minimized [1, 2]. The machinery is suitable both for manufacturing and training needs, as well as for youth innovation centres  or for different festivals of makers . ■
The machining center development works were carried out with the support of the FASIE, Contract No. 422GRNTIS5 / 44715. The authors express their sincere gratitude to the Department of Entrepreneurship and Innovative Development of the City of Moscow and the Ministry of Economic Development of the Russian Federation (Agreement No. 8 / 3-63in-16 of 08/22/16) for their invaluable assistance.