Suche nach „[Rascher] [Rolf]“ hat 185 Publikationen gefunden

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, O. Fähnle, Rolf Rascher

Setting-up high-end cnc grinding processes: a Preston-based approach

Proceedings of EOS Optical Technologies Conferences at the World of Photonics Congress (WPC 2017) [Munich, Germany; June 26-29, 2017]

Abstract anzeigen

The design of grinding processes is commonly based on the principle of trial and error. In most cases this will end up with a usable setup that delivers acceptable results. On the other hand this method is unlikely to reveal the process’s total potential. Allthough the principles of grinding and polishing are entirly different, the preston approach can be used to design grinding processes more intelligent and highly efficient. Carrying out a testing procedure for grinding tools reveals the tool’s removal properties on different materials. This allows to choose ideal sequences of pre and fine-grinding. Furthermore it is possible to choose the optimum machining parameters to optain a maximum output.

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, O. Fähnle, Rolf Rascher

Three wagons Approach Applied to Optimization of Industrial Grinding Processes

Optical Fabrication and Testing part of Optical Design and Fabrication: 9-13 July 2017, Denver, Colorado, United States, Washington, D.C., USA

ISBN: 978-1-943580-31-6

DOI: 10.1364/OFT.2017.OTu2B.2

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Rolf Rascher, Christian Vogt, C. Faehnle

In situ laser polishing optimization method: Control of LASer Surface Optimisation (C-Lasso)

Proceedings of EOS Optical Technologies Conferences at the World of Photonics Congress (WPC 2017) [Munich, Germany; June 26-29, 2017]

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Laser polishing is achieved by local absorption of laser power within the polishing spot causing the surface and its sub-surface region to melt and flow reducing surface roughness and removing sub-surface damage. In this paper we present a novel fabrication controlling method for laser polishing processes called C-Lasso (Control of LASer Surface Optimization, Patent Pending), monitoring in situ the surface smoothening process. It is possible to determine and control the minimum dwell time a footprint needs to stay at a certain point before moving further. C-Lasso enables to avoid unnecessarily long local dwell times. Besides the functioning principle, a proof of concept will be presented as well as experimental data demonstrating the in situ monitoring.

Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, Florian Schneider, Rolf Rascher

Grinding Processes for Silicon Carbide (CSiC) Materials

Proceedings of the 13th International Conference of the European Society for Precision Engineering & Nanotechnology , Berlin

ISBN: 978-0-9566790-2-4

Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, S. Sinzinger, Rolf Rascher

A Study on Elastic Grinding Tools

Proceedings of the International Optical Design Conference, Washington, DC

ISBN: 978-1-55752-747-9

DOI: 10.1364/OFT.2014.OTu3B.3

Abstract anzeigen

This paper reports on results of testruns with experimental grinding tools. The ball shaped tools comprise of abrasive layers with diamond grits, on top of an elastic layer. The tool’s design allows dwell time based corrections on simple and complex shapes, such as spheres and parabolic shapes.

Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

Vortrag

Christian Vogt, R. Stamp, G. Smith, Rolf Rascher, Peter Sperber, Florian Schneider, Roland Maurer, Markus Schinhärl

Strategies for grinding optical free-forms using ball-shaped grinding wheels

SPIE Optifab, Rochester, NY, USA

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The demand for non-spherical surfaces and free-forms is steadily growing. Aspherical lenses can reduce the number of necessary lenses in optical systems e.g. used for lithographic devices for production of microprocessors. Parabolic mirrors can be used to focus light beams highly efficiently because of low absorption rates without colour distortion. Combined optical devices with included mechanical functions for assembly reduce necessary production steps. The most common pre-machining method for small numbers of high-precision lenses and mirrors is grinding. Depending on the required shape there are different options for generating surfaces e. g. spheres, parabolic mirrors or combined forms. The most flexible ones are grinding with (i) workpiece and ball-shaped tool rotating and (ii) fixed workpiece with ball-shaped tool rotating. In this manuscript grinding strategies dealing with meander and spiral tool paths are investigated in order to define which strategy works best for machining off-axis parabolic mirrors.

Angewandte Naturwissenschaften und WirtschaftsingenieurwesenHochschulleitung und -einrichtungenMaschinenbau und Mechatronik

Zeitschriftenartikel

Christian Vogt, S. Sinzinger, H. Adelsberger, Roland Maurer, Florian Schneider, R. Mandler, Lutz Kuepper, Rolf Rascher, Peter Sperber

An Experimental Study on a Flexible Grinding Tool

Advanced Materials Research, vol. 325, pp. 91-96

DOI: 10.4028/www.scientific.net/AMR.325.91

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Robert Schneider, Alexander Haberl, Rolf Rascher

Parametrization of a Subaperture Polishing Tool - Analysis of the Path Tests

Optical Fabrication and Testing part of Optical Design and Fabrication: 9-13 July 2017, Denver, Colorado, United States, Washington, D.C., USA

ISBN: 978-1-943580-31-6

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Sebastian Sitzberger, Christian J. Trum, Rolf Rascher

Analysis of the influence of the workpiece self-weight in precision optics manufacturing using FEM simulation

Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach])

DOI: 10.1117/12.2273023

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, O. Fähnle, Rolf Rascher

Force-controlled analysis tool for optimization of precision CNC grinding processes

Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach])

DOI: 10.1117/12.2272713

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian J. Trum, Sebastian Sitzberger, Rolf Rascher

Advanced method for the characterization of polishing suspensions

Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach])

DOI: 10.1117/12.2272431

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Alexander Haberl, Rolf Rascher

Yet one more dwell time algorithm

Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach])

DOI: 10.1117/12.2270540

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Engelbert Hofbauer, Rolf Rascher, Felix Friedke, R. Kometer

Resolution, measurement errors and uncertainties on deflectometric acquisition of large optical surfaces "DaOS"

Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach])

DOI: 10.1117/12.2267513

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Robert Schneider, Alexander Haberl, Rolf Rascher

Polishing tool and the resulting TIF for three variable machine parameters as input for the removal simulation

Proceedings of SPIE 10326 (Fourth European Seminar on Precision Optics Manufacturing, 1032601 [April 4th-5th 2017, Teisnach])

DOI: 10.1117/12.2267415

Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Vortrag

Rolf Rascher, C. Weingarten

Hybridfertigung optischer Oberflächen

F.O.M.-Konferenz 2016 - Innovative Industrien unterstützen, Berlin

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Zeitschriftenartikel

Engelbert Hofbauer, Rolf Rascher

Deflectometric Acquisition of Large Optical Surfaces DaOS

Using a new physical measurement principle: vignetting field stop procedure

Optik&Photonik, vol. 11, no. 5, pp. 40-44

DOI: 10.1002/opph.201600036

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Zeitschriftenartikel

Engelbert Hofbauer, Rolf Rascher, Manon Schilke, Johannes Liebl, J.-P. Richters

Deflectometric Acquisition of Large Optical Surfaces “DaOS” Using a New Physical Measurement Principle: Vignetting Field Stop

(Reprinted from Proceedings of SPIE Volume 10009: Third European Seminar on Precision Optics Manufacturing, 100090Y [Teisnach, April 12th 2016] doi:10.1117/12.2236134)

Bavarian Journal of Applied Sciences, no. 2, pp. 146-161

Abstract anzeigen

The vignetting field stop procedure uses a deflectometric approach to acquire big Optical Surfaces – DaOS – and it offers the possibility to measure nearly any shape or form using a scanning routine. The basic physical measurement principle in DaOS is the vignettation of a quasi-parallel light beam emitted by an expanded light source in auto collimation arrangement with a reflecting element. Thereby nearly any curvature of the specimen, is measurable. Due to the fact, that even sign changes in the curvature can be detected, also aspheres and freeform surfaces of any size can be evaluated. In this publication the vignetting field stop procedure is discussed. Additionally the deflectometric setup is described. Because of some typical influences of beam deflection to the accuracy of angle measurement by using the vignetting principle, suitable methods of calibration for the sensor are examined and the results of these methods are presented. Furthermore, the technical principle of deflectometric measurements using an angle detecting device is explained inclusive of all random and systematic errors generated by the setup. The last part of this publication shows the actual result of test measurements with calculated absolute deviation of errors with a large lateral dimension as well as the determination of the maximal achievable lateral resolution by detecting mid frequent structures on flat and spherical test parts with a diameter of 300 mm. These measurements are compared critically to reference results which are recorded by interferometry and further scanning methods.

Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Vortrag

Christian Schopf, Rolf Rascher

Reducing forces during drilling brittle hard materials by using ultrasonic and variation of coolant

Optics and Measurement International Conference 2016, Liberec, Tschechische Republik

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Schopf, Rolf Rascher

Reducing forces during drilling brittle hard materials by using ultrasonic and variation of coolant

Proceedings of SPIE 10151

DOI: 10.1117/12.2257106

Abstract anzeigen

The process of ultrasonic machining is especially used for brittle hard materials as the additional ultrasonic vibration of the tool at high frequencies and low amplitudes acts like a hammer on the surface. With this technology it is possible to drill holes with lower forces, therefor the machining can be done faster and the worktime is much less than conventionally. A three-axis dynamometer was used to measure the forces, which act between the tool and the sample part. A focus is set on the sharpness of the tool. The results of a test series are based on the Sauer Ultrasonic Grinding Centre. On the same machine it is possible to drill holes in the conventional way. Additional to the ultasonic Input the type an concentration of coolant is important for the Drilling-force. In the test there were three different coolant and three different concentrations tested. The combination of ultrasonic vibration and the right coolant and concentration is the best way to reduce the Forces. Another positive effect is, that lower drilling-forces produce smaller chipping on the edge of the hole. The way to reduce the forces and chipping is the main issue of this paper.

NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, S. Sinzinger, Martin Rohrbacher, Rolf Rascher

Prediction of grinding tool wear and lifetime by using a test bench

Proceedings of SPIE 10009 (Third European Seminar on Precision Optics Manufacturing, 100090Y [April 12th 2016, Teisnach])