Feeder Mechanism Research Articles

Quantifying Global Warming Response of the Orographic Precipitation in a Typhoon Environment with Large-Eddy Simulations

Abstract The intense and moist winds in a tropical cyclone (TC) environment can produce strong mountain waves and enhanced precipitation over complex terrain, yet few studies have investigated how the orographic precipitation in a TC environment might respond to global warming. Here, we use large-eddy simulation to estimate the global warming–induced change in the precipitation near an idealized mountain (1 km maximum height) with pseudo global warming. Two regions exhibit enhanced precipitation, one over the mountain and the other in the downstream region 25–45 km away from the mountain. The enhanced precipitation in both regions is related to the seeder–feeder mechanism, although the enhancement in the downstream regions differs from the conventional definition and is referred to as the pseudo-seeder–feeder mechanism (PSF). In the PSF, mountain waves generate an intense cloud formation center in the midtroposphere above the lee slope, and the resulting hydrometeors drift downstream, intensifying downstream convection when they fall into proper locations. Under warming, the overmountain precipitation maximum exhibits minimal changes, while the downstream precipitation maximum exhibits a large sensitivity of 18% K−1. The small sensitivity of the first precipitation peak is due to the canceling effects of thermodynamic and dynamic changes. The large sensitivity in the downstream region is mainly due to the strengthening of the wave-induced midtroposphere cloud formation center, which supplies more hydrometeors to the downstream region and enhances precipitation efficiency through the enhanced PSF mechanism. However, the downstream precipitation sensitivity varies with mountain geometry. Higher mountain height enhances precipitation but lowers the sensitivity to warming. Significance Statement The combination of typhoon environment and orography can produce intense precipitation and thereby severe flooding risks. Here, we investigate the global warming response of orographic precipitation in a typhoon environment with idealized, high-resolution simulations. The experiments suggest that under warming, a precipitation maximum may emerge in the downstream region of a mountain or strengthen and shift upwind if it already exists in the current climate. This surprising amplification of downstream-region precipitation is related to the enhancement of the midtropospheric cloud generation caused by mountain waves and has critical implications for flooding risk management in mountainous regions.

A window into development of a complex ice-marginal lake prior to the Late Glacial Maximum (LGM) in Austria

Abstract Although the retreat process of glaciers from the Late Glacial Maximum (LGM) is well documented, high-resolution insight into conditions prior to the maximum is lacking in the eastern European Alps, resulting in a gap in our understanding about the processes associated with this important climatic tipping point. We describe an outstanding sand and gravel outcrop at Gröbming in the Enns Valley (Ennstal), Austria, that represents the development of a delta complex that debouched into a large body of water that we name paleo-Lake Gröbming, fed by a major valley glacier. The succession consists of sands bearing climbing ripples, parallel laminations, and supercritical bed forms (bottomsets) overlain by meter-scale gravelly foresets. Topsets comprise gravels. We argue that sustained accumulation of supercritical bed forms required a jet efflux feeder mechanism best explained by a direct glacial meltwater source. Complex vertical and lateral repetition of this tripartite succession is observed, with sequence stratigraphic analysis permitting us to argue that stratal complexity is attributable to base-level changes in paleo-Lake Gröbming resulting from dam breaches of the lake. Thus, application of well-established sequence stratigraphic approaches to Quaternary ice-marginal successions in the Alps has significant potential to yield unprecedented insights into conditions prior to the LGM.

Vertical Structure and Ice Production Processes of Shallow Convective Postfrontal Clouds over the Southern Ocean in MARCUS. Part II: Modeling Study

Abstract Part I of this series presented a detailed overview of postfrontal mixed-phase clouds observed during the Measurements of Aerosols, Radiation, and Clouds over the Southern Ocean (MARCUS) field campaign. In Part II, we focus on a multiday (23–26 February 2018) case with the aim of understanding ice production as well as model sensitivity to ice process parameterizations using the Weather Research and Forecasting (WRF) Model. The control simulation with the Predicted Particle Properties (P3) microphysics scheme underestimates the ice content and overestimates the supercooled liquid water content, contrary to the bias common in global climate models. The simulations targeted at ice production processes show negligible sensitivity to cloud droplet number concentrations. Further, neither increasing ice nuclei particle (INP) concentrations to an unrealistic level nor adjusting it to MARCUS field estimations alone guarantees more ice production in the model. However, the simulated clouds are found to be highly sensitive to the implementation of immersion freezing, the thresholding of condensation/deposition freezing initiation, and the rime splintering process. By increasing immersion freezing of cloud droplets, relaxing thresholds for condensation/deposition freezing, or removing rime splintering thresholds, the model significantly improves its performance in producing ice. The relaxation of the immersion freezing temperature threshold to the observed cloud-top temperature suggests an in-cloud seeder–feeder mechanism. The results of this work call for an increase in observations of INP, especially over the remote Southern Ocean and at relatively high temperatures, and measurements of ice particle size distributions to better constrain ice nucleating processes in models.

The Effects of submerged vanes inclination angle on sediment transport into sub-channel

The sub-channels that branch from the larger rivers may be manmade or natural. From the major channels, these sub-channels transfer sediments and water. The deposition of sediments at the entrance, sub-channel is a significant research challenge because it threatens the sub-facilities channel's and reduces the sub-carrying channel's capacity. Therefore, submerged vanes were used to reduce the amount of sediment entering the sub-channel. The goal of the vanes is to reduce the amount of sediment entering the sub-channel, hence redistributing sediment at the sub-entry channel's . They are vertically aligned with the flow direction and tilted at a certain angle. A physical model of the main channel, a sub-channel at a right angle, and a sediment feeder mechanism were developed. 51 tests were undertaken, 3 with submerged vanes and 48 without, with a varying number of submerged vanes (7, 5, 3 and 1). And angling it at various angles (10˚, 20˚, 30˚, and 40˚) in the discharge direction and with three sub-discharges of (19.1, 27 and 30.5 l/s), the sediment concentration flow was (6 kg/h). The weights of the sediments in sub-channel were calculated, and it was found that there is an effective use of these vanes and that the least amount of sediments is achieved when the angle is (20ᵓ). It was observed that the performance of the submerged vanes was significantly improved when there was a decrease in the discharge of the sub-channel.

Temperature and cloud condensation nuclei (CCN) sensitivity of orographic precipitation enhanced by a mixed-phase seeder–feeder mechanism: a case study for the 2015 Cumbria flood

Abstract. The formation of orographic precipitation in mixed-phase clouds depends on a complex interplay of processes. This article investigates the microphysical response of orographic precipitation to perturbations of temperature and cloud condensation nuclei (CCN) concentration. A case study for the 2015 Cumbria flood in northern England is performed with sensitivities using a realization of the “piggybacking” method implemented into a limited-area setup of the Icosahedral Nonhydrostatic (ICON) model. A 6 % K−1 enhancement of precipitation results for the highest altitudes, caused by a “mixed-phase seeder–feeder mechanism”, i.e. the interplay of melting and accretion. Total 24 h precipitation is found to increase by only 2 % K−1, significantly less than the 7 % K−1 increase in atmospheric water vapour. A rain budget analysis reveals that the negative temperature sensitivity of the condensation ratio and the increase in rain evaporation dampen the precipitation enhancement. Decreasing the CCN concentration speeds up the microphysical processing, which leads to an increase in total precipitation. At low CCN concentration the precipitation sensitivity to temperature is systematically smaller. It is shown that the CCN and temperature sensitivities are to a large extent independent (with a ±3 % relative error) and additive.

Application of Rail-Type Welding Robot in Automatic Welding of Pipeline

In order to realize the automatic welding of oil and gas pipelines, a kind of rail-type welding robot was designed, which includes a mechanical structure that can walk around the circumference of the pipeline steadily and a control system with the function of welding seam tracking. According to the characteristics of field construction, the robot adopted a modular design method, which primarily consists of a walking mechanism, quick clamping mechanism, welding torch adjusting mechanism, welding torch, wire feeder mechanism, guide rail, and the composition of the control system was introduced besides. The weld center identification and weld tracking were both automatically accomplished by the laser vision tracking system. Through the welding test, it has been demonstrated that the rail-type welding robot can meet the requirements of automatic welding of pipelines.

Design and analysis of feeder mechanism for buckling prevention in robotic catheterization

Abstract In this study, a novel two-degree-of-freedom active-feeder mechanism with a disposable roller module for buckling prevention of the catheter tube was developed and analyzed. The buckling phenomenon occurs when the flexible part cannot withstand a compressive force. Buckling can be prevented using additional parts that support the long flexible part along the tube; however, these passive-type buckling-prevention mechanisms cannot improve transmissibility in a rotational motion. By contrast, the active-type mechanism can transmit both translational and rotational motion but has a bulky structure due to additional motors, which makes placing the mechanism near the patient difficult. Therefore, to solve the afore-mentioned issues, a compact and clinically practicable design is proposed. The proposed feeder mechanism was developed using two driving-shaft modules that enable simultaneous translational and rotational feeding with the minimum number of motors. Furthermore, to minimize the deformation of the tube and obtain sufficient grip force to replicate surgeons’ operation, the analysis was conducted based on contact mechanics. The maximum insertion force and rotating torque were estimated and verified using the measured static friction coefficient. In addition, we formulated an accurate insertion length model based on the experimental results. Using the proposed feeder mechanism and accurate insertion model, the buckling prevention and elimination performance were verified through the experiment on the robot system.

Raindrop size distribution of stratiform precipitation over Southwest India – The Gateway of Indian Summer Monsoon

The study focuses on exploring the bright band (BB) characteristics, using Micro Rain Radar and ceilometer during the monsoon season of 2019 over three stations - coastal (20 m above mean sea level (MSL)), mid (400 m above MSL), and high (1820 m above MSL) altitude cloud physics observatories, setup by the National Centre for Earth Science Studies. The raindrop spectral characteristics are analyzed by classifying the BB events into three time periods, (i) prior to the occurrence of the bright band (pre-BB), (ii) during bright band (BB), and (iii) the subsequent hours after the dissipation of bright band (post-BB). Stronger BB events are noted in the high-altitude station with reflectivity of 33 dBZ at the melting layer while the occurrence of high duration (~2 h) events are noted at the mid-altitude station. Pre-BB hours are contributing the highest surface rainfall from all stages of BB evolution at the coastal and mid-altitude stations. The vertical profile of high rain rates indicates the presence of shallow and mixed-phase precipitating systems during pre-BB hours. At the coastal station, light to moderate rainfall with narrow raindrop spectra having dominance of mid-size drops are noticed. The efficiency of collision-coalescence processes is relatively more at the mid- and high-altitude stations resulting in small to mid-size drops and larger drops respectively. The raindrops generated from the melting layer fall into the shallow feeder clouds formed at the saturated surface in the high-altitude station that creates a seeder feeder mechanism of orographic rain enhancement. The distribution of mass-weighted mean diameter (Dm) varies from 0.5 to 1 mm with wider generalized intercept parameter (log10Nw) values (3–5 m−3 mm−1) at the mid- and high-altitude stations during pre-BB hours. In BB hours, the distribution of Dm values at the high-altitude station extends to 1.5 mm with high log10Nw values and the shape-slope (μ-Λ) relation also shows the extension of raindrop spectra to larger drops. The radar reflectivity-rain rate relations coherently explain the results concerning the evolution of drop spectra. The analysis provides a comprehensive understanding of the precipitation microphysical processes in the elevated terrain of the southwest coast of India, which acts as the gateway of the Indian summer monsoon.

Sustainable metal droplet formationviaopen-source, cost-effective, and modifiable droplet generator

In this study, a metal droplet generator developed with an open-source concept is presented. The continuous droplet generation process was achieved without inert gas assistance. Owing to this desktop device, which is proposed as an alternative to high-cost metal printing devices, users can achieve stable droplets continuously at low costs. Taking into account the pressure balance inside the melting region, the necessary amount of a metal wire feed was first revealed. The droplets generated which are in good agreement with the theoretical calculations were then ejected via mechanically restricted vibrational impacts. The reproducibility of the system was also tested. The droplet formation stages were classified, and the stable parameter groups were revealed in accordance with the measurements. Moreover, the wire type material feeding issue in metal droplet generators, which were insufficiently studied so far, has also been examined. A dynamic feeder mechanism was introduced in detail. In conclusion, Ball Grid Array deposition and functional circuit printing have been successfully achieved. This study on a continuous metal droplet formation is also important for future studies because the structure of the device is easily accessible and modifiable.

Impact of wind pattern and complex topography on snow microphysics during International Collaborative Experiment for PyeongChang 2018 Olympic and Paralympic winter games (ICE-POP 2018)

Abstract. Snowfall in the northeastern part of South Korea is the result of complex snowfall mechanisms due to a highly contrasting terrain combined with nearby warm waters and three synoptic pressure patterns. All these factors together create unique combinations, whose disentangling can provide new insights into the microphysics of snow on the planet. This study focuses on the impact of wind flow and topography on the microphysics drawing of 20 snowfall events during the ICE-POP 2018 (International Collaborative Experiment for PyeongChang 2018 Olympic and Paralympic winter games) field campaign in the Gangwon region. The vertical structure of precipitation and size distribution characteristics are investigated with collocated MRR (micro rain radar) and PARSIVEL (particle size velocity) disdrometers installed across the mountain range. The results indicate that wind shear and embedded turbulence were the cause of the riming process dominating the mountainous region. As the strength of these processes weakens from the mountainous region to the coastal region, riming became less significant and gave way to aggregation. This study specifically analyzes the microphysical characteristics under three major synoptic patterns: air–sea interaction, cold low, and warm low. Air–sea interaction pattern is characterized by more frequent snowfall and vertically deeper precipitation systems on the windward side, resulting in significant aggregation in the coastal region, with riming featuring as a primary growth mechanism in both mountainous and coastal regions. The cold-low pattern is characterized by a higher snowfall rate and vertically deep systems in the mountainous region, with the precipitation system becoming shallower in the coastal region and strong turbulence being found in the layer below 2 km in the mountainous upstream region (linked with dominant aggregation). The warm-low pattern features the deepest system: precipitation here is enhanced by the seeder–feeder mechanism with two different precipitation systems divided by the transition zone (easterly below and westerly above). Overall, it is found that strong shear and turbulence in the transition zone is a likely reason for the dominant riming process in the mountainous region, with aggregation being important in both mountainous and coastal regions.

Microphysical investigation of the seeder and feeder region of an Alpine mixed-phase cloud

Abstract. The seeder–feeder mechanism has been observed to enhance orographic precipitation in previous studies. However, the microphysical processes active in the seeder and feeder region are still being understood. In this paper, we investigate the seeder and feeder region of a mixed-phase cloud passing over the Swiss Alps, focusing on (1) fallstreaks of enhanced radar reflectivity originating from cloud top generating cells (seeder region) and (2) a persistent low-level feeder cloud produced by the boundary layer circulation (feeder region). Observations were obtained from a multi-dimensional set of instruments including ground-based remote sensing instrumentation (Ka-band polarimetric cloud radar, microwave radiometer, wind profiler), in situ instrumentation on a tethered balloon system, and ground-based aerosol and precipitation measurements. The cloud radar observations suggest that ice formation and growth were enhanced within cloud top generating cells, which is consistent with previous observational studies. However, uncertainties exist regarding the dominant ice formation mechanism within these cells. Here we propose different mechanisms that potentially enhance ice nucleation and growth in cloud top generating cells (convective overshooting, radiative cooling, droplet shattering) and attempt to estimate their potential contribution from an ice nucleating particle perspective. Once ice formation and growth within the seeder region exceeded a threshold value, the mixed-phase cloud became fully glaciated. Local flow effects on the lee side of the mountain barrier induced the formation of a persistent low-level feeder cloud over a small-scale topographic feature in the inner-Alpine valley. In situ measurements within the low-level feeder cloud observed the production of secondary ice particles likely due to the Hallett–Mossop process and ice particle fragmentation upon ice–ice collisions. Therefore, secondary ice production may have been partly responsible for the elevated ice crystal number concentrations that have been previously observed in feeder clouds at mountaintop observatories. Secondary ice production in feeder clouds can potentially enhance orographic precipitation.

Influence of low-level blocking and turbulence on the microphysics of a mixed-phase cloud in an inner-Alpine valley

Abstract. Previous studies that investigated orographic precipitation have primarily focused on isolated mountain barriers. Here we investigate the influence of low-level blocking and shear-induced turbulence on the cloud microphysics and precipitation formation in a complex inner-Alpine valley. The analysis focuses on a mid-level cloud in a post-frontal environment and a low-level feeder cloud induced by an in-valley circulation. Observations were obtained from an extensive set of instruments including ground-based remote sensing instrumentation, in situ instrumentation on a tethered-balloon system and ground-based precipitation measurements. During this event, the boundary layer was characterized by a blocked low-level flow and enhanced turbulence in the region of strong vertical wind shear at the boundary between the blocked layer in the valley and the stronger cross-barrier flow aloft. Cloud radar observations indicated changes in the microphysical cloud properties within the turbulent shear layer including enhanced linear depolarization ratio (i.e., change in particle shape or density) and increased radar reflectivity (i.e., enhanced ice growth). Based on the ice particle habits observed at the surface, we suggest that riming, aggregation and needle growth occurred within the turbulent layer. Collisions of fragile ice crystals (e.g., dendrites, needles) and the Hallett–Mossop process might have contributed to secondary ice production. Additionally, in situ instrumentation on the tethered-balloon system observed the presence of a low-level feeder cloud above a small-scale topographic feature, which dissipated when the low-level flow turned from a blocked to an unblocked state. Our observations indicate that the low-level blocking (due to the downstream mountain barrier) created an in-valley circulation, which led to the production of local updrafts and the formation of a low-level feeder cloud. Although the feeder cloud did not enhance precipitation in this particular case (since the majority of the precipitation sublimated when falling through a subsaturated layer above), we propose that local flow effects such as low-level blocking can induce the formation of feeder clouds in mountain valleys and on the leeward slope of foothills upstream of the main mountain barrier, where they can act to enhance orographic precipitation through the seeder–feeder mechanism.

Sensitivity of Snowfall Characteristics to Meteorological Conditions in the Yeongdong Region of Korea

This study investigates the characteristics of cold clouds and snowfall in both the Yeongdong coastal and mountainous regions under different meteorological conditions based on the integration of numerical modeling and three-hourly rawinsonde observations with snow crystal photographs for a snowfall event that occurred on 29−30 January 2016. We found that rimed particles predominantly observed turned into dendrite particles in the latter period of the episode when the 850 hPa temperature decreased at the coastal site, whereas the snow crystal habits at the mountainous site were largely needle or rimed needle. Rawinsonde soundings showed a well-defined, two-layered cloud structure along with distinctive wind-directional shear, and an inversion in the equivalent potential temperature above the low-level cloud layer. The first experiment with a decrease in lower-layer temperature showed that the low-level cloud thickness was reduced to less than 1.5 km, and the accumulated precipitation was decreased by 87% compared with the control experiment. The difference in precipitation amount between the single-layered experiment and control experiment (two-layered) was not so significant to attribute it to the effect of the seeder−feeder mechanism. The precipitation in the last experiment by weakening wind-directional shear was increased by 1.4 times greater than the control experiment specifically at the coastal site, with graupel particles accounting for the highest proportion (~62%). The current results would improve snowfall forecasts in complicated geographical environments such as Yeongdong in terms of snow crystal habit as well as snowfall amount in both time and space domains.

Condition Monitoring of a Paper Feeding Mechanism Using Model-of-Signals as Machine Learning Features

Prognostics and Health Management of machine devices and parts is a hot topic in the Industry 4.0 era. In this fashion, automated procedures to evaluate machinery working conditions are essential to minimize downtime and maintenance costs. In this work, we study how to monitor the decrease in performance of a paper sheet feeder for the packaging industry under heavy-duty cycle operations. The main measurable outcome of such degradation is the increase in backlash among the device moving components. A wide variety of methods and procedures is available to tackle this monitoring problem. In this paper, we analyze the use of a simple yet efficient diagnosis methodology that can exploit machinery controllers (i.e., Programmable Logic Controllers) edge-computing capabilities. Vibration measurements are known in the literature to retain information about the system's mechanics. Model-of Signals, a data-driven approach based on black box system identification, allows to extract that information reliably during machinery working cycle. The refinement of those data using machine learning allows the retrieval of knowledge about the health state of the machine. In this study, the feeder mechanism is run to failure with its parts backlash measured at given time intervals. Accelerometer signals are modelled as AutoRegressive processes whose coefficients are then considered as features to feed to machine learning algorithms, which are employed to perform severity evaluation of the ongoing degradation. Estimation and prediction are both implementable on-board the controller, while the learning task can be carried out remotely, in a cloud computing perspective. The exploitation of AutoRegressive modelling gives a simple and inherent methodology for feature selection, serving as a foundation of the machine learning stage. We make use of a Support Vector Machine algorithm to analyze how obtained models represent the various levels of backlash in the device and develop a suitable predictor of the degradation severity. Finally, the results of the application of the methodology to the case study are shown.

Design and Material Selection of Screw Feeder of Injection Molding Machine

The efficiency of the ‘Injection molding Machine’ lies in the proper designing of screw feeder mechanism. The screw feeding mechanism needs to be setup differently for different materials, molds etc. The proper design includes the work from selecting the appropriate materials, designing for the optimum design, analysis of the designed parts at different flow rates, speed and temperatures. There are various parameters that govern the efficiency of the ’Injection molding Machine’. These parameters include ‘Filling Pressure’, ‘Mold Surface Temperature’, ‘Raw Material Melting Temperature’, ‘Filling Time’ etc.

Automatic Fish Feeder System for Aquaponics using Wi-Fi Based WSN

Aquaponics is a farming method, which is the combination of aquaculture and hydroponics, which grows fish and plants together in one integrated system. The fish waste provides an organic food source for the plants, and the plants naturally filter the water for the fish. The purpose of this project is to build an automatic fish feeder system for aquaponics using image processing technique with the help of Wireless Sensor Network (WSN). This helps the farmers to reduce manual effort and safeguard a balanced food delivery. The number of fish in the pond may vary over time, so the amount of fish feed provided need to be changed. As there will be a large number of fish moving randomly in a pond, the manual tracking and counting of fish is very difficult. It is a time consuming and erroneous process. This work focuses on developing a system that tracks and counts the fish in the pond for aquaponics. This automatic fish identification system processes the video of the entire pond and makes it easier to estimate the count of fish. The frames from the video are processed using Raspberry-Pi board and the count of fish is transmitted through Wi-Fi. Such a system would assist to feed the fish accordingly. Based on the count transferred, a fish feeder mechanism is controlled using NodeMCU at the other end of the Wi-Fi. The amount of fish feed remaining in the feeding box is informed to the user through mobile application.

Short-term variability and mass loss in Be stars

Context. Be stars are important reference laboratories for the investigation of viscous Keplerian discs. In some cases, the disc feeder mechanism involves a combination of non-radial pulsation (NRP) modes. Aims. We seek to understand whether high-cadence photometry can shed further light on the role of NRP modes in facilitating rotation-supported mass loss. Methods. The BRITE-Constellation of nanosatellites obtained mmag photometry of 28 Cygni for 11 months in 2014–2016. We added observations with the Solar Mass Ejection Imager (SMEI) in 2003–2010 and 118 Hα line profiles, half of which were from 2016. Results. For decades, 28 Cyg has exhibited four large-amplitude frequencies: two closely spaced frequencies of spectroscopically confirmed g modes near 1.5 c/d, one slightly lower exophotospheric (Štefl) frequency, and at 0.05 c/d the difference (Δ) frequency between the two g modes. This top-level framework is indistinguishable from η Cen (Paper I), which is also very similar in spectral type, rotation rate, and viewing angle. The circumstellar (Štefl) frequency alone does not seem to be affected by the Δ frequency. The amplitude of the Δ frequency undergoes large variations; around maximum the amount of near-circumstellar matter is increased and the amplitude of the Štefl frequency grows by a factor of a few. During such brightenings dozens of transient spikes appear in the frequency spectrum; these spikes are concentrated into three groups. Only 11 frequencies were common to all years of BRITE observations. Conclusions. Be stars seem to be controlled by several coupled clocks, most of which are not very regular on timescales of weeks to months but function for decades. The combination of g modes to the slow Δ variability and/or the atmospheric response to it appears significantly non-linear. As in η Cen, the Δ variability seems to be mainly responsible for the modulation of the star-to-disc mass transfer in 28 Cyg. A hierarchical set of Δ frequencies may reach the longest known timescales of the Be phenomenon.

Comparative Study between Engineering Stripe and Feeder Stripe

The project work emphasizes the whole information about Engineering Stripe and Feeder Stripe design. Special effort was given to find the basic differences between feeder stripe and Engineering Stripe. This paper is also an attempt to understand about feeder and engineering stripe mechanism, feeding mechanism, tension variation in yarn feeding. Finally, the work revealed that the limitation of 4 finger, 5 finger and 6 finger engineering stripe machine. To continue the project firstly knitted fabric samples along with raw data of different machine parameters, fabric parameters and production parameters were taken.

Development of Experimental Setup of Metal Rapid Prototyping Machine using Selective Laser Sintering Technique

Unlike in the traditional manufacturing processes, additive manufacturing as rapid prototyping, allows designers to produce parts that were previously considered too complex to make economically. The shift is taking place from plastic prototype to fully functional metallic parts by direct deposition of metallic powders as produced parts can be directly used for desired purpose. This work is directed towards the development of experimental setup of metal rapid prototyping machine using selective laser sintering and studies the various parameters, which plays important role in the metal rapid prototyping using SLS technique. The machine structure in mainly divided into three main categories namely, (1) Z-movement of bed and table, (2) X–Y movement arrangement for LASER movements and (3) feeder mechanism. Z-movement of bed is controlled by using lead screw, bevel gear pair and stepper motor, which will maintain the accuracy of layer thickness. X–Y movements are controlled using timing belt and stepper motors for precise movements of LASER source. Feeder mechanism is then developed to control uniformity of layer thickness metal powder. Simultaneously, the study is carried out for selection of material. Various types of metal powders can be used for metal RP as Single metal powder, mixture of two metals powder, and combination of metal and polymer powder. Conclusion leads to use of mixture of two metals powder to minimize the problems such as, balling effect and porosity. Developed System can be validated by conducting various experiments on manufactured part to check mechanical and metallurgical properties. After studying the results of these experiments, various process parameters as LASER properties (as power, speed etc.), and material properties (as grain size and structure etc.) will be optimized. This work is mainly focused on the design and development of cost effective experimental setup of metal rapid prototyping using SLS technique which will gives the feel of metal rapid prototyping process and its important parameters.

Modelling and Simulation of Servo Feeder Mechanism for Punch Press

Modelling and Simulation of Servo Feeder Mechanism for Punch Press