Recently, micro fabrication technology has been attracting attention. In particular, methods that can be used to fabricate microelectromechanical systems (MEMS) and microscopic optical devices, such as photonic crystals, are in huge demand. In this study, we propose a nano-stereolithography method that employs evanescent light instead of propagating light, which allows us to achieve 100-nanometer-level accuracy. The nano-stereolithography method builds 3-dimensional microstructures by curing photosensitive resin in a layer-by-layer fashion. We have had some problems in lateral shape control of a single layer, and dissolved oxygen in resin is estimated to cause the problems. In this report, we focused on a single layer, and substantially improved lateral shape control by nitrogen purge.

View full abstract

This paper focuses the integration of additive manufacturing and subtractive manufacturing into hybrid fabrication concepts. Additive manufacturing (AM), often referred to as 3D printing, has been developing high expectations to open up new markets with novel customized products. However, the advantages of additive fabrication of complex geometries combined with innovative material structures are offset by disadvantages such as the lack of surface quality, precision and accuracy. Hybrid fabrication utilizes the advantages of both technologies and offers opportunities to create new concepts of smart production facilities. Besides comparing the reproducibility of AM processes, different strategies of hybrid manufacturing systems are discussed in this paper. Examples of hybrid manufacturing concepts are presented.

View full abstract

The purpose of this research work is to fabricate micro parts with aligned ferromagnetic short fibers using laser stereolithography and to examine the magnetic properties of the fabricated micro parts. Ferromagnetic short fibers are added to a liquid photopolymer. A magnetic field is applied to the liquid photopolymer, which aligned the axes of the short fibers along the direction of the magnetic field. Then, the photopolymer is solidified with UV laser irradiation in a desired shape. When the magnetic field is applied along the direction of the fabricated part with aligned short fibers, the residual magnetic flux density of the magnetized part becomes about 2 times than that aligned in other directions. The magnetized part can be bent by applying a magnetic field from outside. The magnetized part with aligned short fibers is expected to use for an actuator.

View full abstract

In the field of 3D printing, short fabrication time of three-dimensional model with high precision is demanded. It is necessary to deal with the problem and clarify the phenomenon of 3D printer for higher accuracy. In this study, mechanistic model of delta 3D printer is constructed with MapleSim which is the physical modeling and simulation software, and analyzed the basic response of an extruder head.

View full abstract

Geometric errors of machine tools affect the quality of machined parts. In order to obtain high accuracy in the machining of parts, machined errors of a machined part should be estimated before actual machining. This paper describes a tool swept volume generation method for multi-axis machining with machine tool errors to derive a shape of a machined part and its machined errors. In this paper, the tool swept volume generation method based on the tangency condition and form shaping theory is proposed. To demonstrate the validity of the proposed method, case studies for 5-axis machining with the errors are also presented.

View full abstract

There is a strong need for a new system to shorten the drill fabrication time, to reduce material costs, and to create new drill configurations by predicting their characteristics. Current drill shape prediction systems cannot comprehensively treat drill cross-section shape including the cutting edge, groove and so on, mathematically. Modelling would become more practical if the drill specification was mathematically formulated. This study reports the development of a system to predict not only cross-section shape but also various parameters from grinding wheels used in drill fabrication.

View full abstract

As electronic devices and products are being miniaturized, Printed Wiring Boards (PWBs) within them are also being miniaturized. Therefore, drilling conditions for small and high density holes have become more difficult to decide. We focused on drilling conditions recommended in drill catalogs and attempted to find out the knowledge that experts of drilling use to decide drilling conditions. In this paper, we focused on web thickness, one of the drill parameters, and qualitative variables written in the catalogs. The results clarified the importance of web thickness in drilling conditions and meaning of qualitative variables.

View full abstract

In recent years, reducing the energy consumption of machine tools has been greatly required. Thus, the purpose of this study is to develop the system to generate the tool path so that it effectively reduces the energy consumption of the machine tool. In order to achieve this purpose, the simulation model of the energy consumption is proposed in this study. As the results, it is verified that the proposed model can simulate the energy consumption which varies with difference in the tool path. Therefore, the developed simulation model will be used for generating the tool path that can reduce the energy consumption of the machine tool in the machining process.

View full abstract

In previous studies, a total removal volume (TRV) unit has been introduced and showed its advantages as the alternative of machining features (MF) in feature-based process planning system. The TRV constitutes a volume that needs to be removed in order to make the product shape. Since the estimation of TRV is based on the actual condition of the raw material, the variety of TRV's shapes are more than the traditional MF definition. Therefore, further machining process plan (MPP) which considers both roughing and finishing is needed. In this paper, a TRV-based generative machining process planning system is proposed. A consideration of the product's geometry and dimension tolerances (GDT) is used for representing both roughing and finishing process. This study is based on milling operation on prismatic shapes.

View full abstract

This paper proposed registration of 3D point cloud data sets in reverse engineering of fidelity and precision part by utilization the extracted feature, especially plane features. The objective of proposed method is to solve 3D registration problem of the pairwise data sets with different form and distribution, to improve the fidelity and precision, and to speed up the computation time. This proposed method consists of rough and fine registration. After rough registration, plane features are extracted and validated in correspond grids to be basis of fine registration. Fine registration is then applied based on point-to-point and plane-to-plane registration using ICP by brute force and kD-tree matting scenarios. The experiment showed extraction and validation plane improved the fidelity and precision in both point-to-point and plane-to-plane registration in all scenarios, while kD-tree yielded faster convergence.

View full abstract

Some materials are evaluated for a rat's head positioner. Due to usage environment, selection criteria of the material are MRI compatible and a resistance property of chemical sterilization. Five resins are selected based on the selection criteria of the material. An experiment to reveal a difference of MRI is carried out with using the selected five resins. A copper sulfate phantom and a solenoidal coil are used for the experiment and then the TX-gain value and SNR (Signal to noise ratio) of the obtained images are measured and compared, respectively. TX-gain value is a RF (Radio Frequency) value for controlling the orientation of the hydrogen atom. There is a slight difference regarding both TX-gain value and SNR. Due to this result, the material can be decided by these machinability and cost. A shape of the rat's head positioner is also discussed based on DICOM (Digital Imaging and Communication in Medicine) data of a rat's head taken by CT (Computed tomography). A rat's head shape model is created with using signal strength of the DICOM data. The created rat's head shape is converted to stl data format. A new shape of the head positioner is designed on CAD (Computer Aided Design) based the stl data of the rat's head. A feasibility of the rat's head positioner is introduced by the designed shape.

View full abstract

This paper deals with the optimization of job shop scheduling. The optimal schedule for minimizing a regular objective function such as tardiness of jobs exists in the set of active schedules. It is well known that Giffler and Thompson' algorithm can generate active schedules for job shop scheduling. However, the algorithm does not assign operations of jobs according to time progress in terms of their start times. This paper proposes a new algorithm for generating active schedules in which operations of jobs are assigned according to time progress. Numerical experiments are carried out to show the effectiveness of the proposed algorithm.

View full abstract

An Augmented Reality (AR) technology is implemented for vision-based microassembly operations. A CAD model for the virtual microassembly system is generated and the virtual system is calibrated with real one to simulate the same image features in a virtual environment. By employing the static AR, the hidden feature of mating hole in a rod is reconstructed in image. In the real-time operation, a dynamic AR is implemented to handle the issue of different velocities of moving object in virtual environment and real system. By utilizing the image information from AR, the performance in manual and automatic assembly is experimentally tested. The effectiveness and efficiency of employing AR in peg-in-hole microassembly is concluded.

View full abstract

In our laboratory, a turning method to generate micro shafts by controlling the thrust forces to be zero has been proposed. Applying this method to fabricate brass shafts, it has been clarified that thinner shafts less than 30μm cannot be generate stably, because of the grain sizes of work materials. In this study, the influence of the crystal sizes of brass materials on the machining performance is experimentally investigated.

View full abstract

The cutting of nanoscale-diameter pins, which has not been reported thus far, was attempted using a micro turn-milling machine and microtools made of cemented tungsten carbide. Semicylindrical tools were fabricated by electrical discharge machining and then employed for cutting free-cutting brass. As a result, a straight micropin of 800 nm in diameter was successfully fabricated by turning. This micropin is the first nanoscale-diameter pin fabricated by turning, to the best of our knowledge. No nanoscale-diameter straight pins were fabricated by up-cut or down-cut turn-milling.

View full abstract

This study deals with shoulder cutting phenomena in micro-end-milling of hardened die steels and investigates effects of gash tools and left helix flute tools. We revealed that cutting phenomena become unstable because the end cutting edge is damaged early in shoulder cutting. Therefore, we experimentally prepared a gash tool and left helix flute tool to perform complete processing by improving the strength of the end cutting edge. Cutting experiments were carried out while measuring cutting force and observing cutting phenomena, end cutting edge and machined surface with SEM. As a result, we determined the effects of such tools on fundamental phenomena in shoulder cutting with a micro-end-mill.

View full abstract

This paper describes a new method of molding micro parts using a tool which was manufactured by laminating metallic foils and plates. Coolant channels are circulated uniformly under the tool surface, at a depth sufficiently close to the surface. Hence, the tool temperature can be kept uniform over the large area of inserts of both the movable and fixed die plates. Two stainless steel foils in which micro-gates and cavities are drilled by EDM, respectively, are laminated on the insert of fixed die plate. The space between the insert of movable die plate and the stainless foils, called sheet runner, is first filled with resin due to injection. Thereafter, the micro-cavities are filled with resin through the micro-gates due to the pressure rise in the sheet runner. The process conditions under which polypropylene micro disk of 200μm in diameter and 60μm in thickness can be formed uniformly over the sheet runner area of 40mm by 50mm were obtained changing the injected resin volume, resin temperature, and gate size.

View full abstract

Transparency micro-patterned pad, which have high transmittance at the visible wavelength region and low refractive index equivalent to water, has been developed to observe particle movement during lapping and polishing process directly. The fundamental geometry of the micro pattern has a trapezoidal pyramid shape having the base width of 6.97μm, the height of 2.40μm and the pitch of 12.00μm. In the case of transparency micro-patterned pad at low diffraction index, pyramid pattern contrast in the observation image could be eliminated by filling water between the transparency micro-patterned pad and glass substrate. Therefore, we succeeded observation on the movement of diamond particles by light scattering without interference from the transparency micro-patterned pad pattern. This observation results suggest that the transparency micro-patterned pad would be a useful tool for the dynamic observation directly during the lapping and polishing.

View full abstract

Prediction of the workpiece and tool temperature fields in micro milling of Titanium is important, since it affects the tool wear, has influence on the residual stresses and the 3D distortions of micro parts. An investigation on the temperature of micro milling is performed by considering mechanics and thermal analysis of the process. Considering shearing and frictional heat generations in the primary and secondary zones, temperature fields on the workpiece and on the tool are predicted by Finite Element Analysis. Theoretical simulation and experimental results are presented and discussed.

View full abstract

At the tool rake angle of γ, when the fibre orientation is beyond 90°+γ, chipping is mainly through bending-dominated fibre fracture in the machining of fibre-reinforced polymer (FRP) composites. This paper aims to develop a mechanics model to investigate the material removal in both traditional and elliptic vibration-assisted cutting of unidirectional FRPs when the fibre orientation is between 90°+γ and 180°. In the modelling, the cutting zone was characterized by a microstructure-based region and an equivalent homogeneous material region. Relevant experiments showed that the model has captured the major mechanics and material removal mechanisms and can predict the cutting force, fibre fracture and fibre-matrix debonding with acceptable accuracy.

View full abstract

Mold of micro lens array can be finished with indentation tools that indent and transcribe lens cavities. In the process, ultrasonic vibration applied on tools can improve surface roughness of the cavities. This process requires establishment of rational design of ultrasonic tools. Then, the design method based on FEM analyses are examined for round bar cantilever tools. Since vibration modes and natural frequencies are theoretically determined corresponding with diameter and length of tool, the effects of change in length and diameter on vibration characteristics are examined with FEM analysis. The tool shape for aimed vibration mode can be determined from the natural frequency distributions and additional analysis based on bisection method. The rational design is proposed with description of the algorithm.

View full abstract

Ultrasonic welding is a metallurgical bonding process, which can bond metals together in the solid state. In ultrasonic welding experiments, an SUS436L thin sheet with a thickness of 0.7mm and an SUS304 thin wire with a diameter of 0.2mm were joined. Results indicate that the stainless steel thin wire and sheet can be joined with high efficiency with a strength greater than the shear strength of the material under a short welding time of approximately 0.3s.

View full abstract

In machining of monocrystal sapphire, high efficiency and high precision processing are difficult, because monocrystal sapphire is one of hard brittle materials. This study aims to develop an ultrasonic assisted grinding technology for sapphire wafer. In a previous work, spiral ultrasonic assisted grinding (SUAG) was proposed, and an ultrasonic vibrator was designed and produced. The purpose of this paper is to examine the effect of SUAG for sapphire wafer on grinding force, grinding ratio and surface roughness when a vitrified diamond wheel is used. As the results, applying SUAG decreases the normal and tangential grinding forces, and improves the surface roughness. In addition, the wheel wear using a vitrified diamond wheel is improved.

View full abstract

Structured optical elements such as Fresnel lenses made of glass or polymers are commonly replicated by hot pressing and/or injection molding using high precision molds with 3D-structured surface like V-grooves. In the fabrication of molds, nano-precision polishing is essential as the final process. In this study, a novel polishing method using magnetic compound fluid (MCF) slurry is proposed. The effects of process parameters including MCF slurry supplying amount, workpiece oscillation parameter and MCF carrier rotational speed on work-surface roughness and form error were experimentally investigated. As a result, nano-precision surface finish of structured surface was successfully attained by polishing with MCF slurry.

View full abstract

In machining of Si wafer, high efficiency and high precision processing is demanded. This paper presents the high efficiency mirror finishing of Si wafer using chemical-mechanical machining of fixed abrasive assisted ultrasonic vibration. Ultrasonic chemical-mechanical machining system has been designed and machining experiments have been carried out to clarify fundamental machining properties of proposed method. As a result, the working life of the abrasive pellet becomes longer by suppressing the loading with the ultrasonic vibration; the polishing chip becomes small when ultrasonic vibration is applied. From these results, it is shown that made of defect-free mirror surface is easily compared with traditional chemical-mechanical grinding method.

View full abstract

This paper presents 3D FEM simulation results and their experimental verification performed for turning operations of Inconel 718 heat resistant superalloy using updated J-C (Johnson-Cook) material constitutive model. Machining tests were carried out using grooved carbide cutting tools coated with a TiAlN monolayer without coolants. The selection of machining conditions was based on real production data explored from aircraft plants. The simulations include cutting forces, cutting temperature, plastic deformation in the cutting zone and chip formation. The reference values of friction coefficient were determined using pin-on-disc tribometer. Finally, FEM simulations were compared with measurements in order to highlight the effect of friction coefficient on the chip formation, cutting forces and cutting temperature.

View full abstract

Three distinct segments (segments of the constituent materials and joint area) underlie a bimetallic component. As a result, the surface of a bimetallic is highly complex compared to that of its monometallic counterpart. In this study, bimetallic specimens made of ductile cast iron and Aluminum alloy are turned using different cutting conditions. The surface profile data is obtained by using non-contact surface metrology equipment. The complexity of the surface finish is evaluated by conventional and unconventional parameters (fractal dimension, surface entropy, and possibility distribution). The effectiveness of these parameters is described in detail.

View full abstract

This study demonstrates an application of self-assembled particles to dielectric multilayer film. By changing the permittivity and/or diameters of the particles with layers, the reflectance of particular wavelength electromagnetic waves can be changed. Aiming at selective reflection in the near infrared light, the optical property of the particle structure with different properties fabricated using silica particles (200 nm in diameter) and titanium oxide particles (33 nm in diameter) was investigated.

View full abstract

We investigated influence of iron-based workpiece materials on the characteristics of the Si layers by electrical discharge coating. It was found that the chemical elements of the precipitations were uniformly dispersed in the layer on the workpiece containing the precipitations whose sizes were a few micrometers. By contrast, voids occurred in the layer on the workpiece containing bigger precipitations because the precipitations not melted totally in the coating process were the starting points of the voids. In addition, the surface of the Si layer on FC250 was extremely rough and the distribution of the chemical elements of the layer was inhomogeneous. However, the layer was amorphous and the friction coefficient of the layer was lower than that of the workpiece.

View full abstract

This paper discusses a development of self-cleaning surface. Metal-assisted chemical etching (MACE) is one of the promising processes because it can produce high aspect-ratio structure on a silicon substrate which suits for hydrophobicity. Silica particles (e.g. φ1μm) were self-assembled on a substrate. After the reduction of particle size by argon ion bombardment, gold layer was deposited using the particles as a mask. As a result, gold layer that has openings with regular pitch was obtained. The substrate was then etched with mixture of hydrofluoric acid and hydrogen peroxide. The gold layer works as a catalyst and this part is selectively etched. The oxide layer of silicon is originally hydrophilic. But, it can be changed to hydrophobic by depositing hydrophobic material. Finally, self-cleaning function was examined.

View full abstract

A Molecular dynamics simulation was carried out to clarify the influence of the atomic-scale stick-slip phenomenon on the energy dissipation and friction anisotropy. In the simulation, the sliding processes on an ideal Cu{100} surface by a carbon atom slider were examined by focusing on the two representative sliding directions, such as <100> and <110> using a model in which the cantilever effect of the atomic force microscope was taken into account. As a result, it is found that the dissipated mechanical energy thorough the atomic-scale stick-slip phenomenon can be calculated from the stored elastic energy using the amplitudes of stick-slip force signals. It is also found that the friction coefficient in the sliding in <100> direction becomes higher than that in <110> direction due to the remarkable two-dimensional stick-slip phenomenon.

View full abstract

To improve the wear resistance of small machine parts such as a microscale gears, we developed a new surface treatment process; a laser-induced local surface treatment. Disk-shaped austenitic stainless steel (SUS316L) objects were soaked in Al(NO_3)_3 solution and then irradiated by a nano-pulse fiber laser beam. Treated surfaces were observed with a scanning electron microscopy and analyzed with an energy dispersive X-ray spectrometer. The effect of the defocus amount, tribology behavior and wear resistance on the characteristics of the treated surface were examined. The surface roughness of the treated specimens with the defocus range from -1 to -2 mm was lower than that of the treated specimen without defocus. The thickness of the treated layer decreased when the defocus amount was increased within the abovementioned range of values. However, when treatment was performed with a defocus amount of -3 mm, no noticeable change was observed on the treated surface this was because of the difference in laser-energy density. The friction coefficient of the laser-treated specimen with the defocus level of -1 mm was much lower than that of the untreated specimen. This implies that the wear resistance of austenitic stainless steel can be improved with the developed surface treatment method.

View full abstract

Before occurrence of self-excited chatter, initial resonance has to be grown in turning. In this study, despite external forced vibration, we explain occurrence and growth of SDoF tool oscillation from the trajectory of the tool nose contacting with wavy cylindrical workpiece. By regarding the deviation of the workpiece as a simple sinusoidal function and local contact of the tool with finite radius, we showed the trajectory excites the oscillator under high-order harmonic resonance conditions. The amplitude of the resonance is affected from local contact radius against that of workpiece. From damping effect these resonance conditions are expanded. The growth of the initial resonance would cause either forced or self-excited chatters in afterwards. The occurrence of chatter during wear and the existence of ultra-precision machining are explained from these properties.

View full abstract

A new method for producing gapless biaxial microlens array is proposed for a dual-directional light-control film with a high fill factor. Three steps in this production technique are included for formations of semiellipsoid microlens array with low fill factor to be caulked into gapless biaxial microlens array mold inserts. First, two photoresists with different melting temperatures method will be used to obtain the semiellipsoid microlens array with low fill factor. Second, the air-pressure electroforming caulking is applied to fill the gaps between adjacent lenses after the thermal reflow. Third, the secondary master mold of gapless biaxial microlens array is fabricated for hot embossing process to replicate the array pattern onto PMMA sheet. A gapless biaxial microlens array with long and short axes is developed to change the vertical and horizontal light emitting angles. Based on the simulated and experimental results, the horizontal light emitting angle can be increased to 30° and the vertical one is reduced to 15° by using the biaxial microlens array with high fill factor as the optical scattering film, to effectively enhance optical uniformity for the application of a rear projection display.

View full abstract

The authors propose a new efficient fabrication process by the templated thermal dewetting method in this paper. This process comprises 4 steps. Firstly, sputter etching on a quartz glass substrate. Secondly, line and space pattern of micrometer size is printed with acetone on the substrate by means of stamping with a polymer film stamp. Thirdly, an Au film is deposited on the substrate. Finally, the substrate is annealed. It is revealed that the line and space pattern stamped with acetone on the substrate works as a template of the thermal dewetting process. Nano chemical stamping technique is useful to control the distribution of nanodots size.

View full abstract

A new nano manufacturing method to fabricate minute metal resonators on a quartz glass substrate is reported in this paper. Minute metal resonators are useful for development of optical metamaterials. In this paper, double layer nano-rod resonators are fabricated by utilizing templated thermal dewetting method. The proposed fabrication process separate into two phases; the first process is the fabrication process of a single layer nano-rod array on a quartz glass substrate, and the second process is the fabrication process of a double layer nano-rod array. Through the experiments, effects of process conditions are investigated and optical extinction spectrum of the fabricated double layer nano-rod array is evaluated.

View full abstract

In this paper, functional surface development by controlling crystalline structure on surfaces of materials is suggested. In order to reveal the mechanism of crystalline structure change by Nano Plastic Forming method, plastic deformation characteristics of single crystal pure iron are examined experimentally by means of shearing tests. Stress-strain curves are measured and Critical Resolved Shear Stresses of activating slip systems are calculated based on crystal plasticity theory. Besides shearing tested specimens are annealed and crystalline structure are analyzed by EBSD for study of effects of microscopic plastic deformation and annealing on recrystallization.

View full abstract

The effectiveness of a diamond burnishing method with rotating tool, which is proposed by the authors, is investigated. A proposed hybrid-type parallel mechanism with spherical 5-degree-of-freedom range and force control was used as a burnishing machine. A diamond tipped tool, which is rotated by the high-speed motor spindle, was used as a burnishing tool. A stainless steel surface were targeted. The fundamental characteristics of the proposed method were evaluated by the burnishing mark profile and appearance, surface profile and hardness of the burnished surface layer, and the advantages of the proposed method were clarified by comparing with the conventional method, which is without the tool rotation.

View full abstract

Metal-polymer direct joining is a promising technique but has not been well applied to real industries since many unclear features still remain. This study focuses on one of the joining technique; injection molded direct joining (IMDJ). The IMDJ process is an insert (injection) molding by using a special treated metal piece whose surface nano-structures are formed on by chemical etching. In this particular work, we investigated relationships between molding conditions, which are injection speed and cavity pressure, and tensile shear strength of joining products. The results conclude two interesting findings: the one is the lower speed causes the stronger joining, whereas the other is the speed variations are more effective on the strength than the pack pressure variations.

View full abstract

A hybrid Si-HDPE substrate was developed as an alternative to infrared (IR) lens material in 7.5 to 14μm wavelength using high-precision molding press. HDPE was heated to melt state and pressed onto a Si wafer. Hybrid Si-HDPE with the thin laminated polymer improved IR characteristics of Si. The hybrid substrate then used as an IR lens for night vision camera and the images captured shows similarity to Si filtered images. These results show that hybrid Si-HDPE provide an effective solution for inexpensive IR lens with easy fabrication. Micro dimples can be precisely formed on HDPE for night vision systems lens.

View full abstract

This paper proposes a new pipe-bulging process utilizing a lost core of fiber-reinforced ice. The process is as follows. First, the cavity of the pipe, or channel material, is filled with fiber-reinforced ice, known as the lost core. Second, the pipe is longitudinally compressed as a composite billet, and extruded in the lateral direction. After deformation, the lost core is melted and removed. Low temperature melting alloys are conventionally utilized for the lost core in such processes; however, these alloys usually contain Pb (e.g., Bi-Pb-Sn-In or Pb-Cd system alloys) or are expensive (e.g, In-Sn system alloys). The authors utilize an ice core reinforced with fiber of recycled paper pulp instead of the above alloys for less expensive and more environmentally conscious processes.

View full abstract

This paper presents a design study on an optical setup for fabrication of a two-dimensional grating used in encoder systems. By adding major modifications to the conventional one-axis Lloyd's mirror interferometer, a modified two-axis Lloyd's mirror interferometer has been developed. Based on the wave optics, the two-axis interference patterns to be generated by the proposed optical configuration are simulated. To eliminate unwanted distortion of the two-dimensional micro patterns, polarization of the laser beams is controlled by inserting two half wave plates in the optical path. In addition, pattern exposure tests are carried out by using a prototype optical setup.

View full abstract

Various products have characteristics whose functionality depends on the geometrical arrangement of modules and subcomponents to each other. Therefore ensuring the correct tolerances by alignment processes plays an important role. However, expert interviews reveal that alignment often requires plenty of rework, wherefore it is considered as a wasteful operation. Reducing these unintended efforts can either be done by choosing tighter tolerances or improving the adjustment process itself. Since there are no satisfying methodological approaches to assess both alternatives, the potential of alignment is rarely regarded in the beginning of a product and process development process and thereby planned insufficiently. By applying 3D-printing technology a new type of alignment process is established which is more attractive for in-line production.

View full abstract