An Effect of Screw Extrusion Parameters on a Pottery Model Formed by a Clay Printing Machine

This paper presents a study of the screw extrusion parameters that affect on the appearance of clay filament for a clay printing machine. Traditionally, pottery models are formed by using paster mold or hand throwing, which require experienced and proficient workers to form the complex pottery models. Therefore, the clay printing machine has been developed to improve manual pottery fabrication to automatic construction. This machine has been modified based on the additive manufacturing (AM). To assess a capability material deposition of the clay printing machine, nozzle diameter, screw extruder velocity, and screw pitch were investigated as the printing parameters to evaluate a quality of clay filament. Analysis of variance (ANOVA) is used to analyze main effect parameters. The experimental results showed that the 6 mm nozzle diameter, 19 mm/s screw extruder velocity and 24 mm screw pitch were the suitable printing parameters for providing an appropriate appearance of clay filament. A mathematical model was formulated to propose the relationship between response and main effects with their interactions.

Rancangan Bangun Turbin Mikrohidro Tipe Archimedes Screw Dengan Kapasitas Daya 560 Watt

The performance of a micro-hydro turbine was influenced by several factors, namely the design and the enviromental. This study aims to obtain the appropriate design parameters for the manufacture of screw turbines. This research was focused on blade dimensions and turbine screw pitch distance. The calculations were performed using several screw turbine fixing formulations. The design results show that the optimum blade diameter and turbine pitch range are 0.213 m and 0.312 m at 0.2 m3 / s of turbine inlet water flow and 563.3 Watt turbine shaft output power. The turbine screw test results of the design were carried out in the river flow of Puri Kedaton Housing, Pematang Gajah Village, Rt 13, Jambi Province. The test results show that the highest turbine power occurs at 30 kg shaft loading with a turbine output power of 445 Watts and an efficiency of 78.9%.

Research on Tool Presetting and Tool Deviation in CNC Lead Screw Grinding Process

In the process of tool presetting for an CNC lead screw grinding, when A-axis rotating and Z-axis shifting synchronously according to the screw pitch length, L, of the lead screw workpiece, the handwheel corresponding to X-axis and Z-axis, respectively, is operated to align the grinding wheel with the middle of the screw groove. Then, the coordinates of Z-axis, A-axis and X-axis of the current position are recorded, and the coordinates of the grinding start position and grinding end position of the lead screw workpiece are calculated accordingly.However, due to the mutual following error of Z-axis and A-axis in the synchronous movement process, tool deviation typically occurs when the grinding wheel moves from the grinding start position to the grinding end position to grind the lead screw workpiece. More specifically, the grinding wheel slightly deviates from the middle of the screw groove to the left or right of the screw groove.To offset this deviation, the root cause for creating the deviation is analyzed, and a method to correct the tool deviation is proposed: First, the CNC system sends out grinding instructions, according to the requirements of grinding process, to make the A-axis and the Z-axis move synchronously. In the meantime, the CNC system measures and records the current coordinates of A-axis and Z-axis, and calculates the tool deviation caused by the mutual following error between Z-axis and A-axis. As a result the grinding start position and the grinding end position are adjusted in light of the value of tool deviation in the subsequent grinding process, so as to address the tool deviation issue.

The method for identifying of inaccuracy causes in turning machining center by processing a sample part

The article discusses the issues of the processing method of a turning machining center for processing the accuracy of processing a sample part. The model of sample part with the smallest possible control surfaces processed by various shaping methods has been developed to detect the amount of machine errors, such as the accumulated error of the screw pitch, or the axial non-perpendicularity, or the misalignment of the X and Y drives. This allows you to get more complete information of the equipment accuracy. A test procedure is presented according to the results of measuring each surface of the sample part

Numerical study on the impact of particles filling pattern and screw parameters on the mixing uniformity of wheat grains in a screw mixer

The presence of moisture content in a silo makes the preservation of a grain stock challenging especially when dealing with a large stock. This made it as a major concern for engineers to preserve large crops of grains and avoid huge losses. By installing a screw inside of a silo, the moisture problem could be avoided by stirring the loaded granular bed alongside aeration, also it could be effective to mix different types of loaded materials. The present work has sought to develop predictive models of discrete element method for mixing uniformity assessment when mixing wheat granules in a hopper-bottom screw mixer. The different factors being investigated are: initial configuration of particles, screw rotational direction, screw pitch length, screw diameter and screw rotational velocity. Findings regarding bed homogeneity were calculated using the nearest neighbor’s method. The best mixture was obtained when considering a side-wise filling type of particles ahead mixing and using a 20 mm screw diameter, 30 mm screw pitch and rotating the screw at 80 rpm speed.

Analysis of Extrusion Parameters for the Fused Deposition Modeling Process

Fused deposition modeling (FDM) is an additive manufacturing technology commonly used for three-dimensional printing. The screw rod is an important part of the extrusion nozzle in the FDM manufacturing. The technical parameters of the screw rod, such as the screw pitch, screw angle, groove width, and length-diameter ratio (or aspect ratio), etc., directly determine the speed of extrusion and the precision of modeling. To improve the printing speed and quality of FDM models, this work analyzed the influence of extrusion screw’s parameters on the extrusion flow rate and proposed the best parameters for the screw rod of the FDM process. The results of this work have a crucial significance on the modeling speed and accuracy of the FDM.

Investigating a Novel Design Dental Implant by Using Finite Element Analysis and Experimental Setup

Objectives: In this study, dental implants with three different tooth pitch are designed and tested under static loads and fatigue analysis. In order to reveal the strengths of the different implant designs in dental implant application, the experimental setup where real physical environments were created experimental data was obtained, and these data were compared with numerical data. Materials and Methods: It is difficult to find an analytical solution for problems involving complex geometries. For this reason, numerical methods such as finite element analysis (FEA) are used. For compared finite element results and experimental analysis a new experimental setup has been created to simulate the physical conditions inside the mouth. In this arrangement, the temperature is close to ideal with the acidic environment inside the mouth. Firstly, the geometrical implant system determined on the CNC machine was produced. Results and Conclusion: In this study, dental implant research with 3 different screw pitch was performed. The results obtained from the experimental results were compared with the results obtained from the numerical analysis and it was observed that the accuracy of the numerical analysis was approximately 95%. It was observed that the tensions were less in the dental implant with higher number of screw pitch. In terms of the difficulty of experimental studies, finite element analysis saved both time and money. Thanks to this method, different scenarios can be applied to the optimum design of the dental implant and it can be designed in a computer environment before applying to the patient.

Experimental study on vegetation removing from irrigation channels

The parameters of the process of vegetation removing from the water surface have been justified. An experiment was conducted to determine the strength of the screw-type tool and matching the most appropriate parameters. It was established that the channel clean-up quality depends on the screw diameter. It was also investigated the influence of the screw rotation speed on the channel clean-up quality. The dependence of the cleanup quality on the flight screw pitch has been determined.

A Laser-Based On-Machine Measuring System for Profile Accuracy of Double-Headed Screw Rotor

Great length, large weight and other factors may cause difficulty in measuring the profile accuracy of the double-headed screw rotor. To solve this problem, an on-machine measuring system based on a laser-displacement sensor (LDS) was designed and implemented in this paper by taking an LXK100 four-axis whirlwind milling machine as the carrier. To improve the measurement accuracy of the system, the generalized variable-structural-element morphological method, polynomial interpolation algorithm and ellipse fitting method were first combined to realize the rapid subpixel centroid extraction from a noise-containing spot image, thus improving the data acquisition accuracy of the LDS, and then the hybrid method was experimentally verified. Next, a wavelet threshold function with high-order differentiability and adaptive wavelet coefficient contractility was constructed based on the hyperbolic tangent function, so as to inhibit the disturbance from random errors and preserve real profile information, and this method was simulated and verified. Subsequently, a smoothing algorithm for point cloud data was proposed based on the Lagrange multiplier method to avoid the defect of the piecewise curve-fitting method, that is, function continuity and differentiability could not be satisfied at piecewise points. Finally, the profile accuracy was calculated in real time according to the data reconstruction result and the machining quality was judged. The measurement experiment of the double-headed screw rotor indicates that the proposed on-machine measuring system can complete the profile accuracy measurement for a screw pitch within 39.7 s with measurement accuracy reaching ±8 μm, and the measurement uncertainties of the major axis, minor axis and screw pitch are 0.72 μm, 0.69 μm and 1.24 μm, respectively. Therefore, the measurement accuracy and efficiency are both remarkably improved.

Study on the Lateral Bearing Capacity of Single-Helix Pile for Offshore Wind Power

To support a lighthouse, a trestle and other structures, screw pile has been used as the foundation for more than a hundred years. Because of its efficient installation, high bearing capacity and other advantages, increasing attention has been paid to use it as the offshore wind power foundation. In this research, laboratory test was conducted to study the influence of screw pitch and the diameter of helix on the lateral bearing capacity of single-helix pile, considering the effect of the installation. The results of the single-helix pile were compared with that of steel pipe pile and other methods. According to the test, helix diameter has negligible effect on the lateral bearing capacity of helical pile, but the pitch of helical influence that significantly because of more disturbance of soil.