5-axis Machining Research Articles

Mechanisms of a 3-axis CNC machine design and experiment

CNC technology has become a requirement in the industrial world without complying with educational, pedagogical and private ratings. Manufacturers of this type of machine are trying to conform with the marketing requirements in terms of quality, price and quantity, so the CNC machine can meet the requirements and has acquired a leading position. The study and design of the three-axis CNC machine are based on the Fusion 360 software for the design and PROTEUS software for simulation to perfect our device.

Research of design an educational modular 5 axis milling machine

Industrial CNC machine tools are supplied as closed architecture systems. Their structure, kinematics and CNC controllers are designed to be used exclusively for their basic purpose, without any possibility of being changed. Reconfiguration is seen as the ability to add or remove modules from the machine, to be equipped with additional degrees of freedom (axes). For the concept to become a reality, it is necessary that the machine tool can be easily assembled and disassembled by an end-user and can adapt to changing projects or machining requirements. The approached of this research was to develop a 5-axis modular machine tool, with technological capabilities similar to industrial ones, at an affordable level of development costs and suitable to be used for teaching CAM techniques for future engineers.

Design and modelling of a universal CNC machine

This paper proposes a method of designing an affordable, universal Computer Numerically Controlled (CNC) machine for the use by hobbyists and university laboratories. The machine combines the functions of a 3 to 4-axis milling machine and of a 3D printer. We discuss the major factors contributing to manufacturability and dimensional accuracy of the produced parts, and make several suggestions that aim to maximize the cost effectiveness of the machine’s design. A methodology is developed for optimizing the machine’s rigidity and dimensional accuracy by selecting the proper off-the-shelf components. A calculation that follows the proposed method starts when the required level of accuracy and the machining speed is specified; the result of such a calculation is the overall design of the CNC machine, a bill of materials, and the cost estimate. The design can be optimized for cost, weight, or other parameters. The model presently accounts for the forces generated by the cutting action, the acceleration of machine components, and the associated simple bending moments. The future work in this area relates to the improvement of the proposed method and mathematical model to account for the twisting moments, friction, and vibration.

Performance Characteristics of a Reciprocating Piston Pump Driven by a Wind Machine

The torque applied by a reciprocating pump on a wind machine axis is a fluctuating torque. The energy furnished by the pump on the wind machine axis is absorbed mainly in raising the water and the piston when the latter moves up. This has a direct adverse effect on the starting speed. The lower the maximum torque to be overcome, the easier will the wind machine start. If the necessary torque is high, a faster wind speed is required to start the wind machine. The operating time of the machine is consequently reduced. It is therefore desirable to reduce the starting torque, and hence to make the starting easier. This paper presents a theoretical study to reduce the starting torque of a non-conventional reciprocating piston pump by controlling the stroke volume of the pump or by controlling the flow rate of the piston pump. These two methods are the best to control, smooth and reduce the starting torque of the pump by drilling a very small hole in the piston. The effect of this hole is that at very low speed (at starting) all water that could be pumped is leaked through the hole. This is the main important of the hole which made the pressure on the piston is very low and as a result the starting torque is low. The quantity of water leaking through the hole is small compared to the normal output of the pump. Finally the comparison between normal and leakhole piston pump and the effect of this leakhole on the cavitation phenomena are studied

Design, Integrating and Controlling of Mig-Based Shaped Metal Deposition System with Externally Cold Wire Feed in Additive Layered Manufacturing Technology

Cold wire feeding plus MIG-based shaped metal deposition process has been proved to be a promising technology capable of using materials and energies reasonably to manufacture complex large-scale metal components. The shaped metal deposition with cold wire feeding process is suitable as an alternative technique for traditional manufacturing methods, especially for complex and large-scale solid parts and it is especially used for structural components in aerospace and the manufacture and repair of dying/molds. In this paper, a new experimental setup was developed, which consists of a MIG welding source, an external cold wire feed unit and a 3-axis machine. The paper explains the design, implementation, and stages of control programing (CAD-CAM) of the developed system. Furthermore, the paper presents the important design steps from the design database using CAD to the final shape of the part to be configured. The proposed system is capable of producing parts of different shapes in sizes of more than 450 mm directly from the computer-aided design. Several components are fabricated with SS309L components to achieve the capability of the advanced proposed system. The results showed that the integrated system and the program are feasible and flexible and hence can be used to manufacture variously shaped parts.

An evolutionary neural network approach to machining process planning: A proof of concept

Developments in high degree-of-freedom(DOF) manufacturing processes such as 5-axis machining and additive manufacturing have greatly moderated the design constraint and brought unprecedented manufacturing capability for parts in complex geometry. The advancement in manufacturing processes, at the same time, leads to significant challenges for process planning due to the increasing decision complexity. A method is needed to enable full automated process planning for high DOF manufacturing processes in the foreseeable future. This work focuses on exploring an artificial neural network(ANN) based approach for machining process planning, specifically the toolpath planning for milling operations. The objective of this research is to construct a framework for automated machining process planning that leverages the advancement in ANN methodologies in an attempt to generate an optimized toolpath without any human logic input. In this proposed framework, the voxel model is used as part design and stock geometry representations. An evolving ANN method NeuralEvolution of Augmenting Topologies(NEAT) is applied as the solution algorithm. A prototype implementation of the proposed framework is created and experimented with reasonably simplified machining scenarios and basic part geometries. Initial experiments demonstrate optimistic results supporting the feasibility of creating such an ANN through an evolutionary method to accomplish specific manufacturing requirements on different geometries. The work also revealed that the geometric input is a critical factor for successfully training an ANN model. Further work is needed to encode the part design geometric information as input. Additionally, an improved evolutionary ANN algorithm needs to be created to accelerate the model training.

Postprocessor for Verification of Robot Movements with Additional Axis after Toolpath Optimization

This paper discusses a postprocessor for milling robots connected to additional linear machine axes where toolpath is optimized with respect to variable properties of the robot in its workspace. A toolpath optimization method is proposed based on an experimentally verifiedrobot stiffness model. After postprocessor distribution of the movements between the robot and the linear axes, the collision states during machiningcannot be verified in common CAM. Therefore, a solution enabling simulation of movements after optimization is proposed. The tool center point coordinates are used to control the robot and additional machine axes, while the joint coordinates calculated by inverse kinematic transformation are used to verify the movements.

New mechanistic model to predict machining time for milling free form geometries using 4-axis milling

Predicting the required time to machine a component is very important for planning the production of a factory. However, in milling of free form parts, commercial CAM software are not able to estimate the time precisely. This is because the CAM does not consider individual machine limitations. This work presents a mechanistic method developed to estimate more accurate the time to mill a free form geometry using any 4-axis milling machine. The maximum error observed on experimental validation of the method was less than 6%, 200 times more accurate than commercial CAM.

Effect of inclination and rotation of the sheet on sheet thinning and formability in robot assisted incremental sheet metal forming

Single point incremental forming (SPIF) has higher formability than other sheet metal forming processes. In SPIF, the existing computer numeric control (CNC) incremental forming which adopts 3-axis CNC milling machine to form the part incrementally by using a hemispherical tool has the limitation of forming steeper wall angle parts. An additional 2-degree of freedom (DOF) manipulator has been proposed to integrate with the existing 3-axis CNC milling machine to improve the formability of the sheet. In this method, to control the material flow and deformation state, the posture of the sheet has been changed by tilting the sheet along the needed direction and rotating at specific speed with respect to the vertical forming tool. Formability of the sheet has been investigated in terms of sheet thinning and strain distribution after deformation. Numerical simulation has been implemented initially and has been validated by conducting the experiments. The result of the research shows that formability can be improved by adding the 2-DOF manipulator to the existing system.

Selection of a workpiece clamping system for computer-aided subtractive manufacturing of geometrically complex medical models

Abstract Physical models of anatomical structures can be made using Additive Manufacturing (AM) or Subtractive Manufacturing (SM). The advantage of subtractive techniques over additive ones is the possibility of maintaining the homogeneity and consistency of the processed material, which is extremely important in the case of medical devices. Currently, a geometrically complex medical model can be made even on a simple, 3-axis CNC machine tool. However, often the semi-finished product must be machined in at least two clamping configurations. The aim of the work is to present the method of fixing a workpiece in the process of subtractive production of geometrically complex medical objects on the example of skull bone prostheses. The paper discusses the use of two clamping systems for machining such models. It presents the process of subtractive production of bone prostheses models fitted to the defect of the skull bone with the use of the proposed methods of fixing the workpiece. The result of the work are two models of the skull bone prosthesis. A more complex model was analysed in terms of the accuracy of geometry reproduction. The research confirmed the usefulness of the proposed clamping systems for the preparation of medical models of geometrically complex anatomical structures.

A general identification method for position-dependent geometric errors of rotary axis with single-axis driven

Position-dependent geometric errors (PDGEs) of rotary axis affect the accuracy of the multi-axis machine tool. However, many PDGE identification methods were not general enough and not applicable when the structure of the machine tool was limited or changed. In this paper, a general PDGE identification method with single-axis driven was proposed. Firstly, the comprehensive length change model of the double-ball bar (DBB) was established. The simplification was conducted through the constraint condition to obtain the identification matrix. Then, the effect of the installation errors of the DBB was analyzed and eliminated. Simulations were carried out to validate the correctness of the proposed method when considering the installation errors. Next 10 measurement patterns were determined according to the structure limitation of the small-size 5-axis machine tool. Totally 364 combinations with full rank identification matrix are available. Finally, the prediction experiments and analysis for standard deviation were conducted to further validate the effectiveness of the proposed method. It turned out that the small condition number of the identification matrix can more likely achieve high accuracy. And an improved combination using 5 patterns was proposed with the same accuracy achieved compared to that using a total of 10 patterns.

Autonomously triggered model updates for self-learning thermal error compensation

The presented method significantly increases the self-optimization ability of thermal error compensation models by triggering on-machine measurements when unknown thermal conditions occur. These conditions, which are not represented by the training data of the compensation models, are identified by a novelty detection approach based on one-class support vector machines. The results show that the autonomously triggered on-machine measurements applied to a 5-axis machine tool overcome the trade-off between precision and productivity for thermal error compensation. The non-productive time to detect an exceedance of the predefined tolerances is reduced by 78% without significantly reducing the precision of the thermal error compensation.

Tool-path control for singularity avoidance of 5-axis machine tool by combining circular arc and cubic spline

Tool-path control for singularity avoidance of 5-axis machine tool by combining circular arc and cubic spline

Examination and prediction of process parameters for Surface roughness and MRR in VMC-five axis machining of D3 steel by using RSM and MTLBO

VMC five-axis is modern machining method, used for milling operations that focus on rotary cutters to extract surplus material from a work piece. To achieve machining economics in VMC-5-axis machining, choice of optimum process variables is crucial. Surface roughness and material removal rate are significant response variables, and analyzing and optimizing both the responses combinedly is an important research area in milling. Current research is planned to analyze, model and predict the optimum milling parametric condition of VMC-5-axis machining of D3 tool steel to anticipate surface roughness and MRR simultaneously by applying response surface methodology and multi-objective teaching learning-based optimization (MTLBO). The experiments had been planned as per Box-Behnken design of response surface methodology. Statistical analysis of variance (ANOVA) is applied to determine the significances of milling conditions on milling performance characteristics. ANOVA results revels that milling processing conditions are more significant for MRR as compared to surface roughness. Modeling of responses is made by RSM. Contour plots are drawn from developed mathematical models for visualizing the direct and combined effects of milling conditions on both the responses. Multi-responses are solved by MTLBO technique. Predicted milling condition is verified by confirmatory test. The concluding remarks have been drawn from the study. From the present research work, it is found that milling responses are improved at predicted condition obtained by hybrid RSM and MTLBO approach.

Investigation on probe positioning errors affecting on-machine measurements on ultra-precision turning machines

The measurement of machined surfaces directly on ultra-precision turning machines yields to notable advantages, e.g. in correcting formdeviations without re-clamping. In the present work, a one-dimensional probe is moved by the machine axes to optically scan the workpiece. The integration and positioning methodology of the probe within the machine tool coordinate system as well as a measurement simulation model are presented. Simulations and experiments are conducted to identify the influence of positioning errors of the probe regarding the measurement results. The measurement error along the spindle axis, which mainly affects the measured form deviation, depends on the gradient of the geometry to be measured.

Optimization of CNC technology in the manufacturing process of an artistic product

The work analyses the optimisation of the manufacturing process of an artistic wooden product (mirror frame) with a 3-axis CNC machine. The 3D model was first made in ArtCAM, from where the STL file was later uploaded to SolidWorks. The parameters for the HSR (high-speed roughing), and HSM (high-speed machining) operations were determined in SolidCAM. The findings show that a combination of operations from HSR and HSM are the best choice, considering the shape of the model and the capabilities of the machine, as the best ratio between the quality of the surface and the time needed for the operation is provided by these. Operations differ with regard to the tool path and parameters that can be adjusted. The operations were compared and the best results are achieved when the HSR operations “Contour Roughing” and then “Rest Roughing” are used and when the HSM operation “3D Constant Step Over” is used, where the machining time amounted 4 hours and 1 minute. Finally the G code was made for our product.

A Study on the 5-Axis Machining for Ball Gear Cam

A Study on the 5-Axis Machining for Ball Gear Cam

Experimental Analysis of Single Point Incremental Forming of Truncated Cones in DC04 Steel Sheet

Abstract Experimental tests to form truncated cones were carried out on a 3-axis milling machine. 0.8-mm thick low-alloy DC04 steel sheets were used as test material. The profile tool-path trajectory was generated using the EDGECAM software. The slope angle and diameter of the base of the conical shaped drawpieces were 70°-72° and 65 mm, respectively. The drawpiece heights were up to 75 mm. The full synthetic lubricant 75W85 was used to reduce the frictional resistance. The effect of selected incremental forming parameters on the formability of the DC04 sheet and the susceptibility to crack formation have been analysed and discussed. It was found that the surface roughness of the workpiece is strongly influenced by step depth. By controlling the feed rate, it is possible to prevent failure of the material.

Dynamic model identification for CNC machine tool feed drives from in-process signals for virtual process planning

Virtual process planning offers advantages in terms of predicting servo and contouring errors ahead of time, and taking corrective action by modifying the program or CNC parameters. Successful application of virtual process planning requires accurate models that capture the dynamics of feed drives. Identification of such models is typically time consuming.This paper presents a pole search method used in conjunction with least squares (LS) projection technique for identifying virtual machine tool drives. Compared to earlier research published in rapid identification, and the generic system identification method (i.e., a two-stage instrumental variable method), the parameter convergence has been improved significantly. This is achieved by reducing the number of unknown variables solved during LS estimation from eight to four (corresponding to each candidate pole triplet), and by avoiding the use of noisy position measurements and their time derivatives in the LS matrix pseudo-inversion. As a result, virtual feed drive models can be constructed using only in-process gathered data, without interrupting a machine tool's production for dedicated identification tests. Effectiveness of the new method is demonstrated in simulations and experimental case studies on two different machine tools, a gear grinding machine, and a 5-axis machining center. With the new method, servo errors can be predicted during the process planning stage to within 1-2% of closeness of their actual (experimental) values.

WOODEN MASK MAKING TECHNIQUES WITH 3 AXIS CNC ROUTER MACHINE

This study aims to determine the technique of making wooden masks with a 3-axis CNC Router machine and to compare the time and quality of the results of making masks manually. This research method uses cangkring wood, mahoni wood and pule wood. The design process with the help of the CorelDraw software, Aspire vectric. Manufacturing process with the mach-3 software. The machining process of a 3 Axis CNC Router with a variety of machining roughing and finishing with a variety of tool paths, step over, step down, spindle rotation, plugrate, feederate, and machining time. The results showed making wooden masks with a CNC Router machine has a faster time, uniform shape and size than manual making. Pule wood material provides a faster yield, smoother surface, and machineable than cangkring wood and mahoni wood. The machining time of the CNC router for making one wooden mask is 2 hours-20 minutes for cangkring wood, 3 hours-06 minutes for mahogany wood, and 2 hours-07 minutes for pule wood.