Turn-milling Machine Research Articles

Research on geometric error compensation of ultra-precision turning-milling machine tool based on macro–micro composite technology

Research on geometric error compensation of ultra-precision turning-milling machine tool based on macro–micro composite technology

Optimization of responses in single and multi-point machining processes using Dragon-fly algorithm coupled with TOPSIS and VIKOR decision-making approaches

Due to complex production practices, it is becoming crucial to provide greater thermal management and friction reduction in manufacturing processes. Lubricants play a crucial role by effectively reducing friction, minimizing wear and tear thereby extending the lifespan of the tool. It is observed that there is a shortage of studies associated with the machining of hard materials like Ti-6Al-4V. The present work has therefore focused on the machining of high-grade Titanium alloy under dry and Neem oil aerosol-mist spray wet conditions. The machining is performed on two kinds of machining processes, such as plain facing with single point tool and co-axial turn-mill facing with multi-point cutting tools on computer numerical controlled Turn-mill machine tool. Furthermore, there are very few articles reported on usage of Neem oil (AzadirachtaIndicaL.) as a lubricant. This has motivated the authors to use Neem oil in a mist condition to minimize the quantity of coolant, without compromising on the tool temperature, surface quality, and tool-wear. The responses obtained are subjected to regression analysis to evolve the fitness functions. Multi-objective optimization of these functions is than adopted using Dragon-fly algorithm (MODA) under the constraints of the machining parameters. A set of pareto optimal solutions for each of the machining cases are obtained and are further evaluated using TOPSIS and VIKOR decision-making approaches to achieve the optimal values of the cutting parameters. The optimum parameters for single point cutting under wet conditions were observed as speed (592 rpm), feed (0.058 mm rev−1) and depth of cut (1.00 mm).The corresponding values of responses were tool temperature (37.05 °C), surface roughness (0.128 μm) and tool wear (155.19 μm). The equivalent values for multi-point cutting were determined as 510 rpm, 0.086 mm rev−1 and 0.25 mm. The responses for these optimal conditions are 32.17 °C, 0.725 μm and 45.72 μm in that order.

Synchronous measurement and verification of position-independent geometric errors and position-dependent geometric errors in C-axis on mill-turn machine tools

Synchronous measurement and verification of position-independent geometric errors and position-dependent geometric errors in C-axis on mill-turn machine tools

On-Machine Measurement and Error Compensation for 6061 Aluminum Alloy Hexagonal Punch Using a Turn-Milling Machine

For machining parts with complex shapes, consisting of computer numerical control (CNC) machine tools, different CNC machine tools will be used according to the machining method. If the workpiece is removed for off-machine measurement after machining, when the size is incorrect, it will need to be returned to the CNC machine tool for secondary machining. In this case, the workpiece surface quality and machining accuracy will be affected, which is very time-consuming. On-machine measurement and complex machine center is a key to solve this problem. In the recent researches that the touch probe was integrated on three or five axis machine for error compensation and shape construction based on on-machine measurement, but turning-milling machine was rare. In addition, the most types of parts were thin-walled parts or thin web parts. In this study, a contact measurement system is integrated into a CNC combined turning-milling machine for on-machine measuring. Macro-programming is used to design the machining path of A6061-T6 aluminum alloy hexagonal punch, and the action of probe measurement is added to the machining path. As the measured data exceed the tolerance range, the calculated data are fed back to the controller for machining improvement by compensation. The finished hexagonal punch is measured in a 3D coordinate measuring machine and the error is compared. The experimental results show that the contact probe needs to be corrected before machining, and the size of the corrected workpiece can reach the tolerance range of ±0.01 mm. The size error of rough machining is larger than that of fined machining, and the size error of rough machining will increase with the length of the workpiece.

A triaxial linkage algorithm for the irregular surface machining of backplane using turn-milling compound method

The manufacture of electronic communication equipment has become an important topic in manufacturing industry as they are used more and more widely in daily life. The fine surface machining of electronic communication backplane is still using milling method, and the production efficiency is so low that the production capacity is seriously affected. In this paper, a new method of turn-milling compound machining is proposed, which is applied to the noncircular surface machining of communication backplane, and the algorithm of triaxial linkage turn-milling is studied emphatically. This method is to add a high-speed turntable to the platform of the three-axis machining center as the fourth axis and proposed trajectory fitting and interpolation algorithm which combined UG point cloud information with spline curve fitting; the interpolation and velocity planning algorithm is based on the principle of constant linear velocity of machining tool tip and can improve the machining speed and acceleration smoothing performance perfectly. Through machining verification, the machining time of the same workpiece is decreased from 30 min using traditional milling to 4 min using this method, the surface roughness is less than 1 μm, and the precision is less than ±0.05 mm, which all fully meet the requirements of product.

Precision and energy-efficient ball-end milling of Ti6Al4V turbine blades using particle swarm optimization

ABSTRACT Ti6Al4V is extensively employed in the aviation, biomedical, and energy industries due to its high strength at elevated temperatures, low thermal conductivity, and high corrosion/creep resistance. However, these intrinsic properties have brought many technical challenges during the machining process of turbine blade shape. However, the recent advancements in flexible and precision machining in the state-of-the-art turn-mill machine tools can enable the manufacturing of high-quality turbine blades. In this study, a methodology is developed for the precision and energy-efficient machining of Ti6Al4V turbine blades on turn-mill machine tools. The stock-to-part manufacturing procedure includes the initial turning operation on bar stock, rough flank milling, and final surface finish milling. The developed method encompasses five stages. Utilizing a reconfigured Particle Swarm Optimization algorithm, a 3D Pareto optimal solution set is generated to evaluate trade-offs between surface roughness, specific cutting energy, and material removal rate. Also, the effect of different inclination angles is analyzed, and the optimization method is repeated with varying lead and tilt angles. This work shows that the surface roughness can be effectively reduced by including inclination angles into optimization while improving the machining process's energy efficiency.

Perfect Timing

In life, timing is everything. So, Austria-headquartered large-capacity mill-turn machine tool specialist WFL Millturn Technologies has got it just right with the launch of its myMILLTURN portal. As it turns out, the online platform development was right on cue for the current global coronavirus/Covid-19 pandemic. Andrew Allcock talked to Kenneth Sundberg, managing director of WFL Millturn Technologies’ aftermarket sales, to learn more

The Geometric Accuracy of Complex Surface Using 5-Axis Turn-mill Machine

This paper presents an analysis model for geometric accuracy measurement of marine propeller blades. Geometric accuracy of marine propeller models, which has been finished by machining processes are measured and analyzed using GOM 3D photo-scanning peripheral and software. The methods we used are firstly, marine propeller blades are scanned by GOM Scanner and then the effects of cutting parameters, that is step-over variation on the geometric accuracy are investigated. Inspection of geometric accuracy is performed by comparing the result of 3D scanning measurement of finished propeller with CAD design data using GOM Inspect 2016 software. The results showed that greater step-over value, the deviation value tends to be smaller. Finally, this method is proven effective in measuring by producing similar trends at two measurement position points.

Prediction of chatter stability for enhanced productivity in parallel orthogonal turn-milling

To increase productivity and the material removal rate, an increasing number of factories have been employing multiple tools for simultaneous cutting. Among these tools is parallel orthogonal turn-milling, which is an important parallel-processing method. However, a dynamic interaction occurs during the cutting processes due to the waviness induced on the shared cutting surface and the dynamic coupling through the machine structure, creating machining vibrations, or chatter, which affect the quality of the machined surface. Therefore, to reduce or avoid the vibration problem during the cutting process, chatter stability of parallel orthogonal turn-milling was examined in this study. Initially, a chatter mechanism model of parallel orthogonal turn-milling was designed, and the limit-critical axial depth of the cut formula was obtained. Next, the model parameters of the machine tool were obtained based on the hammer test method. A parallel orthogonal turn-milling stability lobe diagram (SLD) with tool tip runout was constructed. Finally, the experimental results were verified on a high-efficiency turn-milling machine tool. The results showed that chatter can be predicted for parallel orthogonal turn-milling and an SLD can provide a reference for the selection of machining parameters. In addition, the SLD can also guide the formulation of processing technology specifications. Our results are extremely significant for ongoing research in the field of machining methods.

Better Bigger Cuts

Twin-pallet HMC installed at transmission specialist; crusher machine OEM invests in horizontal borer; large turn-mill machine arrives at turbine/pump manufacturer. Steed Webzell provides the details

Research on Cutting Stability of High-Efficiency Micro Turn-Milling Compound Machine Tool Based on Lobes

In order to improve the cutting stability of high-efficiency micro turn-milling machine tools, avoid the chattering problem during the cutting process. In this paper, the chatter problem in the cutting process is studied based on the stable lobes. By analyzing the high-efficiency turn-milling machine tool mechanism and the turn-milling model, the micro turn-milling dynamic dynamic vibration model and the mathematical model of turn-milling chatter are obtained. Then, based on the hammer test method, the transfer function of the tool-workpiece system is obtained, and the turn-milling stable lobes of the high-efficiency micro turn-milling machine tool is constructed. Finally, the research on the stable zone of the turning main spindle parts, the turning back spindle parts and the high-frequency milling part are completed. The experimental research results guide and optimize the selection of cutting parameters for turn-milling process.

Research on Modal Analysis of Precision Micro Slitting Turn-Milling Machine Tool Based on Hammer Experimental Method

In order to improve the dynamic stability of precision micro slitting turn-milling machine tools, reduce or avoid the vibration problem during the cutting process, optimize the machine structure and processing parameters, the modal analysis of precision micro slitting turn-milling machine tool based on hammer experimental method was researched. In this paper, by analyzing the mechanism of precision micro slitting turn-milling machine tools, the multi degree-of-freedom mathematical vibration model of precision slitting turn-milling machine tools is constructed. The precision micro turn-milling machine tool is analyzed based on the hammer experiment analysis. The modal analysis obtained the first five natural frequencies and resonance speeds of the precision micro slitting turn-milling machine tool,including ST26, NN-25UB8K2 and NN-20UB87. The research results show that hammer experimental method can evaluate the vibration modal analysis of precision micro slitting turn-milling machine tools to some extent. The experimental modal analysis results guide and optimize the structural design and processing technology of precision micro slitting turn-milling machine tools.

Research on Automatic Processing Code Generation System Technology of Micro-Turning and milling combined Machine

Turn-milling machine tools have significant advantages in the machining of high-precision small-size parts. Currently, due to the small size and complex structure of the parts used in the turning and milling machine, manually programmed processing code is inefficient and some automatic generation of processing code software steps are complex and lacking in specificity. Based on a self-developed turning and milling machine, this paper establishes a software framework for such CNC machine tools with automatic generation of NC code as the main function line. We simultaneously design and analysis of specific interface development to provid the software part support for the processing code generation of intelligent processing equipment.

A surface modeling method for product virtual assembly based on the root mean square of the regional residuals

The micro-topographic quality of a product’s surface directly affects the performance of the virtual assembly. The computational precision of the fractal dimension has a significant effect on the accuracy of the virtual assembly model. To address the imprecision and large deviation of the calculation method under some conditions, a virtual product assembly surface modeling method is proposed in this article based on the root mean square of the area residuals. First, the fractal dimension of the surface is calculated using the regional residual root mean square (3R method). The feasibility of the 3R method is verified by comparing with the existing methods on isotropic and anisotropic surfaces. Second, the fractal dimension of a real part surface is obtained using the 3R method. According to the Weierstrass–Mandelbrot function, a partial surface model of the machined part is established. The surface contours, roughness, waviness, and flatness of the part are extracted by wavelet transform. Then, the digital surface model for virtual assembly with the same profile parameters is generated by reconstructing the surface contours of the actual parts. Finally, the method proposed by taking the virtual assembly of a VTM200/F5 turn-milling composite machining center guideway is verified in this article.

Integrated energy-efficient machining of rotary impellers and multi-objective optimization

ABSTRACTReduction in energy consumption without compromising flexibility and quality during manufacturing processes is a continuous challenge. Due to the increasing demand for high-quality machine parts having complex features and intricate shapes, machine-tool manufacturers are producing advanced designs, such as turn-mill machine tools that are capable of turning, milling, drilling, and surface machining and can obtain high precision and surface quality. Use of such advanced systems increases the energy requirement of machining processes, hindering efforts to reduce energy consumption. Rotary impellers are the most critical components of turbomachine systems and are manufactured using difficult-to-cut materials. In this study, integrated process planning for the manufacturing of a rotary impeller AISI 304 from bar-stock to a finished part using a turn-mill machine tool with a single setup is accomplished, and the energy-intensive operations are identified. To improve the energy efficiency of the machining process without compromising other operational objectives, the most energy-intensive operations are investigated. By employing the design of the experimental method, data are collected for the features of concern, and the results are analyzed via the analysis of variance method. Furthermore, artificial neural network models are developed, and multi-objective optimization for the finish-cut milling operation is performed using the genetic algorithm.

Chip geometry and cutting forces in gear power skiving

This paper describes a new virtual model for predicting the uncut chip geometry and cutting forces in power skiving, which is a high-speed, versatile gear cutting process. The developed kinematic model is applied in a dexel-based solid modeling engine to extract three-dimensional uncut chip geometry, from which the two-dimensional cross section is obtained via Delaunay triangulation. Cutting velocities along discretized cutter edges are calculated and used to determine the effective rake and oblique angles. Then, force predictions are made using the oblique cutting model and validated using measurements from power skiving trials performed on a DMG MORI NT5400DCG mill-turn machine.

Повышение точности и производительности токарно-фрезерного станка за счет модификации его компоновочного решения

Повышение точности и производительности токарно-фрезерного станка за счет модификации его компоновочного решения

Diversity of assembly error migration and its solution model for heavy duty machine tool

Aiming at the ever-changing assembly error along with operation in the large scale assembly space, the diversity of machine tool assembly error migration and its operation route are characterised by making use of the correspondence relationship between joint surface error and operation distance. The formation and retention of assembly error are respectively revealed by the forward migration and the reverse migration of assembly error. Furthermore, the delayed step function of assembly error migration is constructed to recognise the potential control operation of error migration. Based on the response surface method, the solution model of assembly error migration is established to reveal the diversity of assembly error migration process and the effect of multiple operations. Finally, the design method of assembly process about heavy duty machine tool is proposed, and its effectiveness is verified by gantry-moving type turning-milling machining centre.

Diversity of assembly error migration and its solution model for heavy duty machine tool

Aiming at the ever-changing assembly error along with operation in the large scale assembly space, the diversity of machine tool assembly error migration and its operation route are characterised by making use of the correspondence relationship between joint surface error and operation distance. The formation and retention of assembly error are respectively revealed by the forward migration and the reverse migration of assembly error. Furthermore, the delayed step function of assembly error migration is constructed to recognise the potential control operation of error migration. Based on the response surface method, the solution model of assembly error migration is established to reveal the diversity of assembly error migration process and the effect of multiple operations. Finally, the design method of assembly process about heavy duty machine tool is proposed, and its effectiveness is verified by gantry-moving type turning-milling machining centre.

The Effect of Surface Roughness on Cutting Tool Shape in CNC Lathe C-Axis Turn-mill Machining

The Effect of Surface Roughness on Cutting Tool Shape in CNC Lathe C-Axis Turn-mill Machining