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In multi-axis machining of thin-walled workpieces such as a blade, especially at the semi-finishing and finishing stage, the depth-of-cut is in general selected very conservatively in order to alleviate the deflection of the workpiece during the machining. Moreover, for both semi-finishing and finishing, the depth-of-cut is usually set to be a constant. Aiming at achieving higher machining efficiency while maintaining a good finish surface quality, in this paper we present a new multi-axis machining strategy for thin-walled workpieces based on the idea of variable depth-of-cut machining. The proposed machining strategy strives to maximize the depth-of-cut locally for every cutter-contact (CC) point while respecting a threshold of the cutting force that is normal to the workpiece surface as it is the major effective force causing the deflection. The threshold of the normal cutting force varies depending on the position of the CC point on the workpiece and it is calibrated through physical experiments. A variable offset distance function is defined by setting the offset at each CC point equal to the maximum depth-of-cut at the point and based on which a multi-pass semi-finishing tool path is generated by offsetting the finishing tool path with the computed variable offset distance. Both computer simulation and physical cutting experiments are performed and their results show that a substantial reduction in both total machining time and machined surface error can be achieved by the proposed machining strategy for thin-walled workpieces.

In this study, high-molecular-weight-polyethylene sheets were welded in the butt-joint configuration in order to investigate the effect of welding parameters on the generated forces during welding. The welding procedure was performed using newly developed clamping device with the ability to measure and acquire the forces during welding in X, Y and Z directions (FX, FY and FZ). Using a welding tool with a stationary shoulder and position control, the applied force is kept approximately constant during the entire welding extension. The obtained results enabled the identification of the influence of each individual welding parameter on the applied forces. The axial force is the most influential force during this process, which is responsible for forging pressure and frictional heat, while traverse and rotational speeds have the main effect on the traversing and lateral forces. The developed sensitized clamping system was used in support of welding process optimization to produce quality welds without resourcing to costly force control sensors. Using this device, it was possible to use force as a welding parameter and produce strong welds with mechanical behavior close to the parent materials’.

Transient gap or crack width monitoring is essential for structural health monitoring and failure analysis of large civil structures. In this paper, an innovative multi-axis displacement sensor, which utilises metal foil strain gauges on a strain shunt structure, has been proposed. This displacement sensor has the advantages inherited from metal foil strain sensing, such as low cost, high precision, fast dynamic response and low power consumption, and can also measure displacement in two axes independently. The working principles and sensitivity are derived theoretically from key geometrical parameters of the shunt structure, and the linear response of strain values to the given displacement of two translational axes has been demonstrated experimentally. Furthermore, modal response, stress concentration, optimal gauges installation positions and bending deformation due to moment of the third axis are studied numerically.

Purpose This study aims to introduce a new method for locating candidate substrates in part models and evaluating their feasibility. Design/methodology/approach Slices of an STL model along candidate directions are evaluated for the fitting of regular cylindrical and rectangular stock. Next, the part model is skeletonized and tested for collision assuming deposition growth of features from the candidate substrate. Findings The method is successfully able to find feasible substrates and conduct collision simulation for a variety of part models. Research limitations/implications The algorithm is limited to cylindrical and rectangular substrates and only considers collision between the substrate and the deposition head. Originality/value This method represents a new approach to solving a portion of the hybrid manufacturing process planning problem.

This article proposes a method to analyze and compensate geometric errors of six-axis CNC grinding machines for spiral bevel gears. Volumetric error prediction and compensation models are realized by the forward and inverse kinematics modeling via the screw theory. Key geometric error items of motion axes and their influences on gear tooth performance are modeled and analyzed. Advantages of the proposed compensation method for geometric errors over the machine settings modification method are demonstrated. The compensation strategy has been verified on a six-axis grinding machine controlled by a Siemens CNC. The pitch error and tooth form error of machined gears before and after compensation are compared to validate the effectivity of the proposed compensation method.

In the current practice of multi-axis machining of freeform surfaces, the interface surface between the roughing and finishing process is simply an offset surface of the nominal surface. While there have already been attempts at minimizing the machining time by considering the kinematic capacities of the machine tool and/or the physical constraints such as the cutting force, they all target independently at either the finishing or the roughing process alone and are based on the simple premise of an offset interface surface. Conceivably, since the total machining time should count that of both roughing and finishing process and both of them crucially depend on the interface surface, it is natural to ask if, under the same kinematic capacities and the same physical constraints, there is a nontrivial interface surface whose corresponding total machining time will be the minimum among all the possible (infinite) choices of interface surfaces, and this is the motivation behind the work of this paper. Specifically, with respect to the specific type of iso-planar milling for both roughing and finishing, we present a practical algorithm for determining such an optimal interface surface for an arbitrary freeform surface. While the algorithm is proposed for iso-planar milling, it can be easily adapted to other types of milling strategy such as contour milling. Both computer simulation and physical cutting experiments of the proposed method have convincingly demonstrated its advantages over the traditional simple offset method. Keywords: Feed rate, Finishing and roughing process, Interface surface, Iso-planar tool path, Physical constraints

In milling of hard-to-cut materials such as Titanium and Ni-based superalloy, tool wear increases rapidly and the tool life can be as short as a few minutes. Moreover, tool wear will influence the workpiece geometrical accuracy and surface quality. Aiming at improving the tool life in multi-axis milling of freeform workpieces made of Ni-based superalloy with a ball-end cutter, this paper introduces a new multi-axis milling strategy for freeform surfaces based on the idea of shifting the active cutting edge on the cutter. The proposed machining strategy tries to use different cutting edges on the cutter to cut the material for different portions of the workpiece surface as each edge element can only be used in the cutting for a short time. The relationships between the tool orientation, active cutting edge and cutter-workpiece engagement are established, and the tool wear rate is approximated in predicting the tool life for each edge element in the milling process. Both the cutter edge and cutter contact curve are divided into several segments according to the maximum cutting length of each cutter edge segment. Tool orientation is then planned based on the shifted active cutting edge. Cutting experiments are performed and their results show that a large improvement of tool life can be achieved by the proposed machining strategy.

Multi-axis robotic Force/Moment (F/M) sensors are capable of simultaneously detecting multiple components of force (Fx, Fy, and Fz), as well as the moments (Mx, My and Mz). This enables them to be frequently used in many robotic applications. Accurate, time-effective calibration and decoupling procedures are critical to the implementation of these sensors. This paper compares the effectiveness of decoupling methods based on Least-Squares (LS), BP Neural Network (BPNN), and Extreme Learning Machine (ELM) methods for improving the performance of multi-axis robotic F/M sensors. In order to demonstrate the effectiveness of the decoupling methods, a calibration and decoupling experiment was performed on a five-axis robotic F/M sensor. The experiments demonstrate that the ELM based decoupling method is superior to LS and BPNN based methods. The presented theoretical and experimental demonstrations provide a comprehensive description of the calibration and decoupling procedures of multi-axis robotic F/M sensors. This work reveals that the ELM method is an appropriate and high performing decoupling procedure for multi-axis robotic F/M sensors.

With the rapid development of aerospace, energy, and power technologies, the demand for high-performance parts with complex curved surface is increasingly large, and the multi-axis Computer-Numerical-Control (CNC) precision machining technique for such parts becomes a popular and difficult issue in the industrial field. In order to ensure the high-performance of complex curved surface parts, the requirement of the contour accuracy is higher and higher for such parts due to the important role they play in these fields. However, the limitation of dynamic properties for the CNC machine tools, which leads to the contouring-error, becomes a vital issue that affects the machining accuracy of the high-performance parts with complex curved surface. The contouring-error, defined as the orthotropic distance from the actual motion position of machine tool to the desired contour of curved surface in multi-axis contour-following tasks, is caused by the facts such as servo lag, dynamics mismatch, external disturbances, and so forth. The reduction of the contouring-error becomes of great significance for promoting the performance of CNC motion systems thus realizing the high-speed and high-precision machining, and the research on the contouring-error reduction in multi-axis CNC machining is therefore a hotspot issue in the machining engineering. This paper provides a comprehensive review to the state of the art of the contouring-error reduction methods. The massive and complicated studies on constraining the contouring-errors are classified and summarized, and accordingly, the advantages and the disadvantages of different kinds of methods are discussed and compared, which has a guiding significance for selection of the interested contouring-error reduction method. Furthermore, this paper systematically suggests the probable future studies that remain vacant and meaningful based on the discussion of the state of the art. Significantly, it is possible for active promoting and developing to further improve the contouring-error reduction of the complex curved surface parts in multi-axis CNC machining.

The improvement of the accuracy grade of main components in the production process through balancing between function and cost helps to improve the overall accuracy of machine tools. Therefore, this paper presents an improved value analysis method and uses the method of global sensitivity analysis and geometric error correlation analysis to analyze and optimize the error parameters of a 4-axis machining tool based on the proposed method. The geometric error modeling of the 4-axis machine tool was established by using the homogeneous transformation matrices (HTMs). By using global sensitivity analysis, the degree of influence of each error parameter on the accuracy of machine tool was obtained, and functional coefficient and cost coefficient of value analysis were gained by correlation analysis. An optimization model for geometric error budget of machine tool was established according to the improved value analysis theory, and the machining accuracy of machine tool was optimized according to the improved value analysis method.

Die Auslegung von Vorschubantrieben in Werkzeugmaschinen ist zu meist ein sehr fehleranfälliger Prozess, da es schwierig ist, abzuschätzen, wie sich die Maschine unter Belastung dynamisch verhält. Diese Veröffentlichung stellt einen Finite-Elemente-basierten Ansatz vor, wie eine Antriebsregelung in eine Mehrkörpersimulation integriert werden kann und wie das Zusammenspiel von zwei Antrieben im Prozess simuliert und optimiert werden kann. The design of feed forward drives in machine tools is frequently an error-prone process, because it is difficult to estimate how the machine tool acts dynamically during processing. This publication introduces a new finite-element-based approach that integrates axis controllers and is able to simulate and optimize the multi-axis behavior of two axes in a process.

This paper proposes an integrated geometric error prediction and compensation method to eliminate the positioning inaccuracy of tool ball for a double ball bar (DBB) caused by the translational axes’ geometric errors in a multi-axis machine tool (MAMT). Firstly, based on homogeneous transform matrix (HTM) and multi-body system (MBS) theory, the positioning error model only considering the translational axes of a MAMT is established. Then, an integrated error parameter identification method (IEPIM) by using a laser interferometer is proposed. Meanwhile, the identification discrete results of geometric error parameters for the translational axes are obtained by identification experiments. According to the discrete values, the optimal polynomials of 18 position-dependent geometric errors (PDGEs) are founded. As a basis, an iterative compensation method is constructed to modify the NC codes generated with the ordinary compensation method in self-developed compensation software. Finally, simulation verification is conducted with these two compensation methods. Simulation results show the positioning errors for test path of tool ball calculated with the iterative compensation method that are limited within 0.001 mm, and its average accuracy and accuracy stability are improved by 79.5 and 52.2%, respectively. In order to further verify the feasibility of the presented method, a measuring experiment is carried out in XY plane of a five-axis machine tool by using DBB. The experiment results show that the maximum circularity error with the iterative compensation method is reduced about 40.4% than that with the ordinary compensation method. It is therefore reasonable to conclude that the proposed method in this paper can avoid the influence of the translational axes’ geometric errors on rotary ones during a DBB test.

Process planning for hybrid manufacturing, where additive operations can be interlaced with machining operations, is in its infancy. New plastic- and metal-based hybrid manufacturing systems are being developed that integrate both additive manufacturing (AM) and subtractive (machining) operations. This introduces new process planning challenges. The focus of this research is to explore process planning solution approaches when using a hybrid manufacturing approach. Concepts such as localized AM build ups, adding stock to a CAD model or section for subsequent removal, and machining an AM stock model are investigated and illustrated using virtual simulations. A case study using a hybrid laser cladding process is used to demonstrate the opportunities associated with a hybrid solution. However, unlike machining, the process characteristics from system to system vary greatly. These are portrayed via a high power, high material deposition feed rate laser cladding system. There are unique challenges associated with AM processes and hybrid manufacturing. New tools and design rules need to be developed for this manufacturing solution to reach its potential.

Multi axis CNC machine tool has good linkage processing effect. Through the application of integral impeller in CNC machine tools, to improve the adaptability of CNC machine tools to complex surface processing parts, to improve the accuracy of multi axis CNC machine tools. The first part of this paper introduces the integral impeller and its machining characteristics; the second part introduces the basic NC machining process of integral impeller; the third part discusses the application of impeller in multi axis CNC machine tools from the creation of guide track, the simulation of integral impeller, software processing and generation. The purpose is to provide some reference for the processing and production of integral impeller.

On-machine inspection is an important technology for the precision fabrication. Plagued by overlapping structure and positioning error from machine tool, it is a challenge to generate an on-machine inspection path. In this paper, a rotation theory is investigated for balancing efficiency and accuracy. Based on the kinematic chain of the machine tool, an accessible space graph is established to demonstrate this theory. The least rotations, the least direction reversions can be recognized from this graph. In term of these principles, an orientation planning method is proposed for the parts with overlapping free-form surface. At last, the advantages of proposed path generation method are verified on an impeller’s on-machine inspection.

Due to the layer stacking inherent in traditional three-axis material extrusion (ME) additive manufacturing processes, a part's mechanical strength is limited in the print direction due to weaker i...

Accuracy identification of geometric errors of rotary axis is important for error compensation of the multi-axis machine tool. However, it is not easy because of the influence of setup error of measurement instrument, and there exists angular errors and displacement errors need to be identified simultaneously. In this paper, a decoupled method based on double ball bar is proposed to identify the geometric errors of rotary axis including both position independent geometric error (PIGE) and position dependent geometric error (PDGE). A formulation for ball bar measurement is derived from kinematic analysis to reveal the relationship between sensitivity direction and setup position of ball bar. The angular errors and displacement errors can be identified separately when choosing the appropriate setup position and direction of ball bar. It can effectively reduce the interaction influence between them and improve the accuracy. To identify the 4 PIGEs, a method by averaging the measured results of ball bar to compute the eccentricity and slant of rotary axis is proposed. And, the PDGEs are leaved to mainly describe the oscillation of geometric errors of rotary axis. It is useful to correct the deviation error resulting from setup error of ball bar. For the identification of 6 PDGEs, by means of adjusting setup position and direction of ball bar, they can be identified one by one along the sensitivity direction of ball bar. Furthermore, in order to reduce the influence of setup error of ball bar, the sensitivity analysis is performed to obtain the sensitivity of measured results of ball bar with respect to setup error. According to the sensitivity characteristics of setup error, a method is presented to correct the PDGEs. Finally, several numerical simulations and experiments are conducted to verify the theoretical model and the proposed identification method. The results from the simulations and experiments demonstrate that the method can identify the geometric errors of rotary axis effectively and accurately.

In this paper, a velocity connection algorithm of arbitrary multi-axis linkage is presented with regard to the problem of velocity connection efficiency of multiple straight-line paths in the motion control system. For this algorithm, with the velocity, acceleration and displacement of the current segment and the previous segment as constraint conditions, the acceleration is not set as a constant but the intersegmental velocity variable is set independently. The initial velocity and final velocity of each segment is solved on this basis, improving the movement efficiency and simplifying the calculation. Therefore, this algorithm is particularly suitable for the high-speed movement mechanism driven by a stepper motor. As for the actual motion track of the rapid prototyping machine, a comparison was made between this algorithm and the traditional velocity connection algorithm to verify the effectiveness of this algorithm.

The message scheduling and the network-induced delays of real-time networks, together with the different inertias and disturbances in different axes, make the synchronous control of the real-time network-based systems quite challenging. To address this challenge, a decentralized multi-axis synchronous control approach is developed in this paper. Due to the limitations of message scheduling and network bandwidth, error of the position synchronization is firstly defined in the proposed control approach as a subset of preceding-axis pairs. Then, a motion message estimator is designed to reduce the effect of network delays. It is proven that position and synchronization errors asymptotically converge to zero in the proposed controller with the delay compensation. Finally, simulation and experimental results show that the developed control approach can achieve the good position synchronization performance for the multi-axis motion over the real-time network.

The ISO accuracy test standard for five-axis machining centers was revised recently. A cone frustum cutting test by end milling, well-known for testing multi-axis controlled machine tools for aircraft part processing, is adopted in the ISO standard as a similar and precise test. It considers both the accuracy of the finished test piece and an interpolation accuracy test measured by ball bar in the same-feed motion of cone frustum cutting. Although it is possible to apply the ISO test methods to various structures of five-axis machining centers, the application of the cone frustum test to multi-axis machine tools with a rotary axis on the workpiece side is rare; thus, it is difficult to evaluate the test results. In this report, the ISO test method was outlined. Next, the ball bar cone frustum test was performed on a five-axis machining center whose two rotary axes were located on the workpiece side. The evaluation method of the test results is discussed. Moreover, the ball bar cone frustum test was also performed on turn-mill complete machining centers to confirm the effectiveness.

Additive Manufacturing (AM) technologies require innovative design paradigms and guidelines that exhaust the offered freedoms in geometry and material. The aim of the Design for Additive Manufacturing is to provide design opportunities and to enhance workpiece properties taking into account constraints of the process, e.g. kinematics and limitations of print technology. Most AM applications are constrained to three-axis movements limiting the fabrication of workpieces layer by layer to one fixed building direction only. This causes limitations of strength properties, surface quality and the need of supporting structures. Multi-axis AM enables completely new design possibilities going beyond current optimization and design strategies of conventional AM workpieces. This innovation requires multiple design and manufacturing changes in the internal and external geometry of the workpiece as well as in machine and printing head technology. This paper identifies the requirements and capabilities of multi-axis AM and presents possible solutions to overcome the identified challenges. Preliminary results for multi-axis AM are described on an exemplary workpiece.

In this paper, proved that the Perpendicularity Error in as a translation error element modeling and as the angle error element modeling on the error precision of the model and modeling of complex different influence degree. For multi axis machine tools, from the complexity of angle error modeling process, as modeling complexity is less than the translational error as the angle error the modeling, error of perpendicularity accumulate, distinguish the complexity is more obvious, mainly the additional angle error matrix in the modeling the matrix. Compensation from the point of view, this study shows that, for only need displacement compensation of the machine tool, the compensation effect of two kinds of the modeling results are the same, but for multi axis machine tool needs angle compensation, compensation matrix as the angle error the modeling accuracy obtained is higher than that of as translational displacement. Comprehensive analysis, this paper puts forward in multi axis machine tool error synthesis the modeling priority when the verticality error as a translation error the modeling.

Accuracy design constitutes an important role in machine tool designing. It is used to determine the permissible level of each error parameter of a machine tool, so that any criterion can be optimized. Geometric, thermal-induced, and cutting force-induced errors are responsible for a large number of comprehensive errors of a machine tool. These errors not only influence the machining accuracy but are also of great importance for accuracy design to be performed. The aim of this paper is the proposal of a general approach that simultaneously considered geometric, thermal-induced, and cutting force-induced errors, in order for machine tool errors to be allocated. By homogeneous transformation matrix (HTM) application, a comprehensive error model was developed for the machining accuracy of a machine tool to be acquired. In addition, a generalized radial basis function (RBF) neural network modeling method was used in order for a thermal and cutting force-induced error model to be established. Based on the comprehensive error model, the importance sampling method was applied for the reliability and sensitivity analysis of the machine tool to be conducted, and two mathematical models were presented. The first model predicted the reliability of the machine tool, whereas the second was used to identify and optimize the error parameters with larger effect on the reliability. The permissible level of each geometric error parameter can therefore be determined, whereas the reliability met the design requirement and the cost of this machining was optimized. An experiment was conducted on a five-axis machine tool, and the results confirmed the proposed approach being able to display the accuracy design of the machine tool.

Multi-scale optical sensor systems help to overcome the area of conflict between resolution, field size, and inspection time if it comes to the frequent problem of detecting small defects on large areas. The sensors of such systems are chosen according to two main properties: On the one hand, they should measure in opposed scales; on the other hand, their measurement principles should vary as well in order to be suitable for different material and surface properties. However, these systems can only operate at full capacity if it is possible to unify the acquired data from each sensor into one common coordinate system such that an overall analysis is possible, or subsequent sub-measurements can be triggered. In this paper, a general approach for a common sensor referencing is proposed, whose focus lies on microscopic optical sensors for both scattering and reflecting surfaces. The method is able to handle resolutions from the nanometer to millimeter scale in one single system, but is also feasible for a coordinate unification across several single sensor systems.

Long-duration blasts are typically defined by positive pressure durations exceeding 100ms. Such blasts can generate dynamic pressures (blast winds) capable of exerting damaging drag loads on comparatively slender structural components such as columns. With limited drag coefficient availability for specific structural geometries, Computational Fluid Dynamics (CFD) can be the only satisfactory approach for analysing blast loading on user-specified, finite geometries. The ability to analyse long-duration blasts with commercially available CFD programs is still not confidently offered, with no prior studies examining the accuracy of modelling interaction with relatively much smaller, finite geometries. This paper presents a comparative investigation between numerical and experimental results to assess the predictive capacity of inviscid Eulerian CFD as a method for calculating long-duration blast drag loading on finite cross-section geometries. Full-scale long-duration blast experiments successfully measured surface pressure-time histories on a steel I-section column aligned at four orientations. Calculated pressure-time histories on exposed geometry surfaces demonstrated good agreement although reduced accuracy and under-prediction occurred on shielded surfaces manifesting as overestimated net loading. This study provides new understanding and awareness of the numerical capability and limitations of using CFD to calculate long-duration blast loads on intricate geometries.

The article considers the design and the mathematical model of multi-axis electric drive with permanent magnets. This device is aimed at use in robotics. Description of research depicts the motor construction needed for this drive, the mathematical formulas that descript the interaction between the electromagnet and the permanent magnet in the motor and two control algorithms that provide position control in three angular axes of motion. At the end of the article, the experimental results are shown.

Multi-axis testing is growing in popularity in the testing community due to its ability to better match a complex three-dimensional excitation than a single-axis shaker test. However, with the ability to put a large number of shakers anywhere on the structure, the design space of such a test is enormous. This paper aims to investigate strategies for placement of shakers for a given test using a complex aerospace structure controlled to real environment data. Initially shakers are placed using engineering judgement, and this was found to perform reasonably well. To find shaker setups that improved upon engineering judgement, impact testing was performed at a large number of candidate excitation locations to generate frequency response functions that could be used to perform virtual control studies. In this way, a large number of shaker positions could be evaluated without needing to reposition the shakers each time. A brute force computation of all possible shaker setups was performed to find the set with the lowest error, but the computational cost of this approach is prohibitive for very large candidate shaker sets. Instead, an iterative approach was derived that found a suboptimal set that was nearly as good as the brute force calculation. Finally, an investigation into the number of shakers used for control was performed, which could help determine how many shakers might be necessary to perform a given test.

In this paper, the presented approach resolves important aspects that appear in the process planning for multi-axis Direct Laser Additive Manufacturing: smoothing of the nozzle orientation along the toolpath to reduce deviation of the laser spot’s surface speed, redistribution of the toolpath points on the surface to ensure robust processing of the points by the machine tool, collision avoidance between the nozzle and the workpiece by adjustment of the nozzle orientation. Collision avoidance penalizes the lateral tilting to minimize the change of the laser spot size due to tilting and, therefore, it has reduced its impact on the process.

Multi-axis mechanical stress sensors have become an important tool in numerous fields. To characterize the quality and resolution of a new stress sensor, researchers use test platforms to apply controlled amounts of shear and normal stresses. Since commercially available multi-axis test platforms are expensive, in many cases researchers end up needing to build their own sensor characterization platforms. In this study, we describe a cost-effective multi-axis stress sensor characterization platform to reduce development time, enable accurate benchmarking and provide an open source standard for stress sensor characterization for other researchers. In our design, we combined a 3-axis translational stage and a 3-axis force and torque (F/T) sensor through custom hardware and software. Our platform is cost effective and can reach the limits of the F/T sensor (Fxy = ±65 N and Fz = ±200 N) without losing any accuracy to structural bending. We provide detailed construction and operation instructions as well as results of extensive static and cyclic load experiments. To further validate our system, we show characterization results from a custom stress sensor as a case study. The modular nature of our platform also enables other researchers to customize this characterization platform for their unique experimental requirements. Keywords: Mechanical characterization, Stress sensor design, Testing stage, Stress sensor calibration

The low cost of manufacturing prosthetics is achieved by using 3D printing technology. In the 3D printing technology there are many methods of manufacturing but I have used fused deposition modeling. In this materials used are polylactic acid, thermoplastic polyurethane and aluminum for manufacturing the prosthetic foot. Polylactic acid and thermoplastic polyurethane materials do not required any preheating of the bed in manufacturing. As the cost of the prosthetic foot are higher and we want to reduce its cost and make available in the market as many people are not able to have an prosthetic foot due to its high cost. It may help common people to afford this foot and obtain nearly to the gait cycle standards. In this paper we will be knowing how to reduce the cost of the multi axis prosthetic foot without any compromise with gait cycle

This paper presents a topology optimization approach that incorporates restrictions of multi-axis machining processes. A filter is defined in a density-based topology optimization setting, that transforms an input design field into a geometry that can be manufactured through machining. The formulation is developed for 5-axis processes, but also covers other multi-axis milling configurations, e.g. 2.5D milling and 4-axis machining by including the appropriate machining directions. In addition to various tool orientations, also user-specified tool length and tool shape constraints can be incorporated in the filter. The approach is demonstrated on mechanical and thermal 2D and 3D numerical example problems. The proposed machining filter allows designers to systematically explore a considerably larger range of machinable freeform designs through topology optimization than previously possible.

In this paper a laboratory stand is presented that was developed for a multi-axis machine stepper drive control system. Each stepper drive utilizes an EtherCAT communication module based on a development board with software developed by the authors. The modules are used to exchange process data with a higher level controller. The EtherCAT communication standard is described including it’s utilization for stepper drive control. A functional description of the developed communication module is also presented. The aim of the Laboratory stand is to conduct research of cyclic communication (1 milisecond or less) and synchronization between multiple drive slave devices and a supervisory controller. The main focus of the presented results was to determine EtherCAT communication cycle jitter on the developed modules. The main aim of the research was to verify whether the data exchange via EtherCAT bus has an impact on the synchronous operation of the multi-axis system.

In additive manufacturing, infill structures are commonly used to reduce the weight and cost of a solid part. Currently, most infill structure generation methods are based on the conventional 2.5-axis printing configuration, which, although able to satisfy the self-supporting condition on the infills, suffer from the well-known stair-case effect on the finished surface and the need of extensive support for overhang features. In this paper, based on the emerging continuous multi-axis printing configuration, we present a new lattice infill structure generation algorithm, which is able to achieve both the self-supporting condition for the infills and the support-free requirement at the boundary surface of the part. The algorithm critically relies on the use of three mutually orthogonal geodesic distance fields that are embedded in the tetrahedral mesh of the solid model. The intersection between the iso-geodesic distance surfaces of these three geodesic distance fields naturally forms the desired lattice of infill structure, while the density of the infills can be conveniently controlled by adjusting the iso-values. The lattice infill pattern in each curved slicing layer is trimmed to conform to an Eulerian graph so to generate a continuous printing path, which can effectively reduce the nozzle retractions during the printing process. In addition, to cater to the collision-free requirement and to improve the printing efficiency, we also propose a printing sequence optimization algorithm for determining a collision-free order of printing of the connected lattice infills, which seeks to reduce the air-move length of the nozzle. Ample experiments in both computer simulation and physical printing are performed, and the results give a preliminary confirmation of the advantages of our methodology., arXiv admin note: text overlap with arXiv:2003.05938