Linear Motion Guideways – A Recent Technology for Higher Accuracy and Precision Motion of Machine Tool (original) (raw)
Related papers
Procedia CIRP, 2016
The main goal of this research work is to investigate and characterise the geometric accuracy and its effect on the performance of the guiding system in machine tools or CMMs. As geometric errors are one of the main sources of the volumetric errors in manufacturing systems, it is necessary to carry out a comprehensive geometric measurement of their components such as guiding systems. Lack of care during assembly can cause some kinds of errors in the guides and other components which may lead to over-determination of the system. In this research, some pre-defined geometric deviations in horizontal, vertical and both directions are applied to the guides and their corresponding influences on the accuracy are recorded. Straightness measurements in horizontal and vertical planes, and also roll, pitch and yaw angular measurements are carried out as a function of axis position. The motion errors of a typical ball bearing linear guide with a slide mounted on four carriages are analyzed. Except for the roll angular measurements which are conducted using electronic levels, all the other ones have been carried out employing laser interferometry method. Various locations of the slide are measured to find out the role of position for straightness and angular measurements. FEM simulations have been then used to model the experiments. Good agreements between the experimental and numerical results are observed. The location of the work-piece on the slide also has an important role for various motion errors.
Studies on the Possibility of Using Linear Motors in Drive of the Machine Tools
ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2010
Linear drive technologies are steadily expanded in various applications, especially in industry, where high precision electrical direct drive systems are required. This paper analyzes the advantages of using linear motors in kinematic chains of machine tools.
Meccanica, 2011
The main topic refers to enhancing the machining accuracy by minimizing the path error while machining through linear, circular or other interpolations on CNC machines for milling, boring and milling, grinding or turning. Currently the path error minimizing process while machining on CNC machine tools is a little explored, because of the absence of the dependence relations between the path error and the parameters of the kinematical axes taking part to the interpolation of the work piece contour. This work establishes and analyzes the relations of dependence between the path error and the response times of the kinematical axes that take part to the linear and circular interpolation. The theoretical results are experimentally verified by performing several machining operations through circular interpolation, where the moving speed along the contour and the response times of the kinematical axes are modified. The results of this research are intended for the machine tool designers and those who use such machines.
Tool path generation, simluation and optimization of a five-axis milling machine
2004 IEEE Region 10 Conference TENCON 2004., 2004
This paper presents the algorithms to generate and simulate non-linear tool path of the five-axis milling machine. The simulator is based on rD representation and employs an inverse kinematics approach to derive the corresponding rotational and translation movement of the mechanism. The simulator makes it possible to analyze an accuracy of a 3D tool path based on a prescribed set of the cutter location (CL) points as well as a set of the cutter contact (CC) points and the tool inclination angle. The resulting trajectory of the tool path is not unique and depends on the initial set up of the machine which in turn is problem dependent. Furthermore, the simulator can be used to simulate the milling process, verif, the final cut and estimate the errors of the actual tool path before the real workpiece is actually cut with the real machine. Thus, it reduces the cost of iterative trial and error. Tool path generation and simulation is verified by a series of cutting experiments performed by means of the proposed software and the accuracy of milling is estimated. It has been shown that the proposed graphical 3D software presents an efficient interactive approach to the modification of a tool path based on an appropriate set of transformations as well as verification of the tool path optimization algorithms. The result of the simulation has been tested using the Maho600E S-Axis Milling Machine at Computer Integrated Manufacturing Laboratory at the Asian Institute of Technology.
A common task in geometric modeling is to interpolate a sequence of points or derivatives, sampled from a curve, with a parametric polynomial or spline curve. To do this the first step is to choose parameter values corresponding to the interpolation points. In a parametric environment, user can completely define a geometric feature with some parameters. This paper has an aim to generate a smooth tool trajectory spline for machining a workpiece. With the spline technique MATLAB program has been proposed for simulation of cutter contact points in the trajectory. The author has gone through C 0 continuity concept and at last the simulated result has been shown by MATLAB program in its output.
Description formats of tool trajectory suited to High-Speed Machining
Numerous works have shown that the linear format of tool path is not well adapted to HSM for it does allow an optimal follow-up of the tool trajectory by the NC unit, nor a good part surface quality. This paper deals with formats of tool trajectory relying on polynomial models. The tool path can be described as polynomial curves as well as polynomial surfaces. Geometrical and dynamical advantages of using such formats are exposed.
Smooth trajectory generation for five-axis machine tools
This paper presents a smooth spline interpolation technique for five-axis machining of sculptured surfaces. The tool tip and orientation locations generated by the CAM system are first fitted to quintic splines independently to achieve geometric jerk continuity while decoupling the relative changes in position and orientation of the cutter along the curved path. The nonlinear relationship between spline parameters and displacements along the path are approximated with ninth order and seventh order feed correction splines for position and orientation, respectively. The high order feed correction splines allow minimum deviation from the reference axis commands while preserving continuous jerk on three translational and two rotary drives. The proposed method has been experimentally demonstrated to show improvements in reducing the excitation of inertial vibrations while improving tracking accuracy in five-axis machining of curved paths found in dies, molds and aerospace parts.
Motion accuracy of NC machine tools
… of the 9th WSEAS International Conference …, 2008
Abstract: Modern CNC machines have two principal systems: the cutting system and feeding system. Work piece accuracy is the overall outcome of cutting and feeding systems. This paper investigate the contour errors (circular and square corner path) on the bases of a ...
Optimization and correction of the tool path of the five-axis milling machine
Mathematics and Computers in Simulation, 2007
We introduce three algorithms for optimization of a tool path of a numerically controlled five-axis milling machine. The unifying idea is a flexible geometric structure which adapts itself to a certain cost function defined on the required part surface. Algorithm 1 is based on the variational grid generation, Algorithm 2 is based on a new modification of the space filling curves techniques. Algorithm 3 is based on construction of vector fields composed of optimal cutting directions. The algorithms verified by numerical experiments as well as by practical machining display a priority with the reference to the standard methods.