Influence of the Kinematic System on the Geometrical and Dimensional Accuracy of Holes in Drilling

This article attempts to show how the kinematic system affects the geometrical and dimensional accuracy of through-holes in drilling. The hole cutting tests were performed using a universal turning center. The tool was a TiAlN-coated Ø 6 mm drill bit, while the workpiece was a C45 steel cylinder with a diameter of 30 mm and a length of 30 mm. Three kinematic systems were studied. The first consisted of a fixed workpiece and a rotating and linearly moving tool. In the second, the workpiece rotated, while the tool moved linearly. The third system comprised a rotating workpiece and a rotating and linearly moving tool, but they rotated in opposite directions. The geometrical and dimensional accuracy of the hole was assessed by analyzing the cylindricity, straightness, roundness, and diameter errors. The experiment was designed using the Taguchi orthogonal array method to determine the significance of the effects of the input parameters (cutting speed, feed per revolution, and type of kinematic system) on the accuracy errors. A multifactorial statistical analysis (ANOVA) was employed for this purpose. The study revealed that all the input parameters considered had a substantial influence on the hole quality in drilling.

Analyzing the Effects of the Kinematic System on the Quality of Holes Drilled in 42CrMo4 + QT Steel

This article discusses the relationship between the kinematic system used in drilling and the quality of through-holes. The drilling was done on a CTX Alpha 500 universal turning center using a TiAlN-coated 6.0 mm drill bit with internal cooling, mounted in a driven tool holder. The holes were cut in cylindrical 42CrMo4 + QT steel samples measuring 30 mm in diameter and 30 mm in length. Three types of hole-drilling kinematic systems were considered. The first consisted of a fixed workpiece and a tool performing rotary (primary) and linear motions. In the second system, the workpiece rotated (primary motion) while the tool moved linearly. In the third system, the workpiece and the tool rotated in opposite directions; the tool also moved linearly. The analysis was carried out for four output parameters characterizing the hole quality (i.e., cylindricity, straightness, roundness, and diameter errors). The experiment was designed using the Taguchi approach (orthogonal array). ANOVA multi-factor statistical analysis was used to determine the influence of the input parameters (cutting speed, feed per revolution and type of kinematic system) on the geometrical and dimensional errors of the hole. From the analysis, it is evident that the kinematic system had a significant effect on the hole roundness error.

VERICUT - CONFIGURING CNC SYSTEMS FOR TURNING CENTER WITH SUB-SPINDLE

This report discusses the configuration of some preparatory and auxiliary commands for the Fanuc 18i TB CNC system for a counter-spindle lathe using special macros called Vericut macros. In most cases, this is necessary because the Vericut library of machines and CNC systems does not have the specific machine and system or do not correspond to the actual ones, i. e. there is no match between them. The need to configure the CNC control system is related to the fact that it is possible to perform simulation, optimization and verification of control programs in a virtual environment before proceeding to the processing of workpieces on the real machine.

Design and optimization of CNC based polishing process

In recent years many aerospace manufacturing corporations have taken an initiative to eliminate the manual interaction of workers and moving work pieces. At the same time there is an ever-increasing demand for efficiency in the manufacturing sector. The research performed investigates the design and development of passive compliance polishing tools for both external and internal polishing of parts on a CNC turning center. The goal of this thesis is to develop tools that meet new safety demands while at the same time optimizing the tools through the Taguchi method and process planning in order to meet quality standards cost effectively. Experiments on both test pieces and production parts were conducted not only at Ryerson University but at Messier-Dowty as well.

Design and optimization of CNC based polishing process

In recent years many aerospace manufacturing corporations have taken an initiative to eliminate the manual interaction of workers and moving work pieces. At the same time there is an ever-increasing demand for efficiency in the manufacturing sector. The research performed investigates the design and development of passive compliance polishing tools for both external and internal polishing of parts on a CNC turning center. The goal of this thesis is to develop tools that meet new safety demands while at the same time optimizing the tools through the Taguchi method and process planning in order to meet quality standards cost effectively. Experiments on both test pieces and production parts were conducted not only at Ryerson University but at Messier-Dowty as well.

Characterization of Thrust Force, Temperature, Chip Morphology and Power in Ultrasonic-assisted Drilling of Aluminium 6061

In this study, a special resolution V design and Response surface methodology (RSM) were used to characterize the ultrasonic-assisted drilling (UAD) process of Aluminum 6061. This characterization was done through developing mathematical models to study the effect of ultrasonic and drilling parameters including spindle speed, feed rate and amplitude on thrust force, temperature, chip morphology and power. The tests were done using an industrially hardened non-rotating UAD system mounted in a CNC turning center. The analysis of variance (ANOVA) was used to find significant parameters of thrust force, temperature, chip morphology and power. Then, for all responses, the optimum drilling parameters that provide desired solutions for all responses were obtained. This was followed by out-of-sample testing to verify the accuracy of the developed models. The results of this study showed that in UAD of aluminum, the minimum values of thrust force and chip size were obtained at low spindle speed, low feed rate and high amplitude. The results also showed that amplitude was not a significant parameter affecting the tool temperature and cannot be used to analyze the effect of ultrasonic vibrations on generated heat during UAD. Instead, the interaction of amplitude and feed rate was significant and should be considered in the analysis. Finally, minimum consumed power, specially at higher amplitudes, can be obtained using high spindle speed and low feed rate.

Modeling of the vibroacoustic dynamic system “machined workpiece-slide” of turning center

Settlement dependences on determining the vibration characteristics of the machined workpieces, taking into account geometric, physical and mechanical characteristics and the force impact from the side of the cutting tool are established. In determining the dependences the effective coefficient of vibration energy losses was taken into account, providing the required value of which, is achieved by reducing vibration in the source due to the use of vibration-absorbing materials.

DEVELOPMENT OF A POSTPROCESSOR FOR TURNING CENTER AND MULTI-TASK MACHINE WITH MULTI-CHANNEL CNC SYSTEMS

This article discusses the possibility of developing a postprocessor for turning center with 2 turrets and a multi-channel CNC system with NC program format characteristic of machine Mazak Integrex I series. Typical for these CNCs is the usage of two support programs - one for each turret. The CAD / CAM system PTC Creo is used to solve the problem, where tool transitions are developed for machining the workpieces. The postprocessor is software that translates the CL Data file i.e. turns it into a NC program with preparatory, technological, and supplementary commands to control the machine. G-POST, which is integrated into the PTC Creo CAD / CAM system, is used to develop the post-processor. To solve the problem, a specialized programming language FIL (Factory Interface Language) is used which, with its features and capabilities to work with files in ASCII code, achieves the ultimate goal - NC program in format characteristics suitable for machines Mazak Integrex I series.