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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Konstrukce malé CNC frézky / Design of small CNC milling machine

Jagoš, Roman January 2012 (has links)
This master´s thesis deals with design of small CNC milling machines and comparing CNC tabletop milling machines in the world market. It is also done design of small CNC milling machine through the use of contemporary and modern trends, used in design of machine tools.
152

Konstrukční návrh malé modelářské CNC frézky / Design of small hobby CNC milling machine

Večeř, Petr January 2016 (has links)
This thesis deals with the structural design of small model CNC milling machines. The work includes research modeller CNC milling machines available primarily on the Czech market, on whose basis are then selected the appropriate parameters for machine design. The thesis contains further structural calculations, selection of appropriate components, production drawings and 3D model that shows the final solution of constructed facility.
153

Wear of tube mill liners for South African power industry

Skorupa, Jan J 22 November 2016 (has links)
No description available.
154

Low cost semi-industrial 3GDL CNC vertical milling center design with non-ferrous metal machining capability

Shimabukuro, Satoshi, Diaz, Piero, Vinces, Leonardo 01 September 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / This work proposes the design of a low cost semi-industrial three degree of freedom CNC vertical milling center (VMC) with non-ferrous metal machining capabilities. The design seeks to mitigate the difficulties that acquiring a commercial industrial CNC can present, such as large dimensions, high cost and complications in its transportation within the plant. The proposed machine will be made up of 1 NEMA 23 stepper motor for each X, Y and Z axis, and will be controlled by open source firmware using an ATMEGA 2560 microcontroller. Likewise, the working area will be 320x180mm and will have a precision 100 microns with semi industrial capacities. This design is aimed at small and medium-sized companies that are looking for a low cost non-ferrous CNC milling machine that in turn has the quality, performance and precision of an industrial one.
155

Comparison of the accuracy between 3D printed and milled dental models by a digital inspection software

Alvi, Shan 27 October 2017 (has links)
STATEMENT OF PROBLEM: The production of full arch dental models through Rapid Additive Prototyping (3D Printing) have been questioned for their accuracy in the past decade. PURPOSE: To compare the accuracy of 3D printed and milled dental models, using a digital metrology software. MATERIALS AND METHOD: A mandibular arch typodont was duplicated to produce a conventional Type IV dental stone model. This Model was scanned to create a digital model and an STL file was created which would be sent to Milling and 3D printing machines.15 models were printed using 3 different 3D printing companies and 10 models Milled with a CNC (Computerized Numeric Controlled) milling machine. Each model was scanned and a digital model was created. These scanned models were then super imposed to the scan of the master model through an inspection software (Geomagic Control X, 3D Systems) for accuracy of production. RESULTS: The mean difference in measurement in Absolute Gap, by either of the two methods of prototyping adopted, (0.075 mm for 3D Printed and 0.084 mm for milled) are well below the clinically acceptable values mentioned in previous literature. The means in absolute tooth distance discrepancy for both prototyping methods (0.0361 mm for 3DPand 0.0353 mm for Milled) were not statistically significant. CONCLUSION: 3D printed dental models were more accurate statistically than milled dental models. In general, the mean accuracy for both methods of rapid prototyping is within clinical tolerance and both are clinically acceptable.
156

The modelling of the binary adsorption of gold and zinc cyanides onto a strong base anion exchange resin

Glover, Michael Richard Lister 05 February 2015 (has links)
No description available.
157

Shockwave consolidation of nano silver powder into bulk nano structured silver

Zhang, Li, 1973- January 2007 (has links)
No description available.
158

A New Procedure for Specific Cutting Force Assessment in High-Speed End Milling

Omar , Omar 04 1900 (has links)
<p> High-speed machining (HSM) concepts were developed in response to productivity, quality and cost concerns. Significant advancements in controls and machining technologies have recently come together to enable the wide spread use of HSM on the plant floor. However, with the advancement of HSM technology, dynamic problems associated with modern machine-tool structures have not been fully addressed and are currently limiting performance in some applications. <p> A key aspect in the modelling of HSM processes is capturing the dynamics of the system during cutting. Machining over a wide range of rotational speeds necessitates the inclusion of many more higher modes in the system than traditionally considered. In addition many of the instruments used to assess performance such as force dynamometers are not designed to measure the cutting forces at high rotational speeds and hence the specific cutting force values being used are often times not being estimated properly. </p> <p> Thus the focus of this research is to develop a new procedure for predicting the specific cutting forces in the end-milling process for high-speed machining. An improved mechanistic model to predict the specific cutting force using acceleration data captured from the workpiece fixture was developed. The development of the new procedure has also lead to an improvement in the extraction technique used to establish the modal parameters of a machining system. This new extraction technique was found to be more flexible and easier to use than other available techniques. </p> <p> The new procedure was investigated to test the effect of choosing the number of modes of the improved modal parameters extraction technique on the estimation of the specific cutting force. The effect of filtrating the acceleration signal and the importance of including the run-out of the cutting tool in the model were also investigated. </p> <p> The new procedure was tested on different setups and with different cutting force models. Experimental validation of the proposed estimation procedure was carried out, analyzed and compared to the open literature. The new procedure was found to be more accurate while being easier to implement. </p> / Thesis / Doctor of Philosophy (PhD)
159

Face Milling Simulation to Correlate and Predict The Effects of Machine Tool Geometric Errors on Part Flatness Tolerance

Iyer, Vipin V. 13 October 2014 (has links)
No description available.
160

TRACES OF MATERIAL AND PROCESS

EBERHARD, PARKER BROWNE 01 July 2003 (has links)
No description available.

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