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Suche nach „[Rolf] [Rascher]“ hat 181 Publikationen gefunden
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    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Rolf Rascher, Christian Schopf

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

    Proceedings of SPIE 10151

    2016

    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)

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

    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])

    2016

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Rolf Rascher, Christian J. Trum

    Improving efficiency of chemo-mechanical polishing processes by systematic selection and conditioning of the polishing suspension

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

    2016

    DOI: 10.1117/12.2236000

    Abstract anzeigen

    During design of optical systems or individual components, customers and designers already predetermine the way through production and the necessary resources. They define the tolerances that are required for their application like shape, micro-roughness and cleanliness, as well as the glass material that is necessary for the targeted optical effect. By the tolerances, they have also an influence on the manufacturer and his decisions on the production environment, measurement technology and the process chain that in his opinion is necessary to meet the specification. In most cases the type of polishing suspension and its parameters are also predetermined by the use of central polishing supply systems. With this paper, the authors want to give a prospect of a currently running research with the aim of increasing the efficiency of chemo-mechanical polishing processes by a systematic selection and conditioning of the polishing suspension. They want to show that small amounts of well-conditioned and stabilized polishing suspension could be a tool to improve the efficiency in CMP processes under the influence of the global trend to products that are more individual and down to one piece flow production. Main parts of this research are the identification of influences of polishing suspensions on the quality criteria of optical components and the creation of a method to find well-working suspension parameters in a deterministic and reproducible way. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

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

    Deflectometric acquisition of large optical surfaces (DaOS) using a new physical measurement principle: vignetting field stop procedure

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

    2016

    DOI: 10.1117/12.2236134

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Rolf Rascher, Horst Linthe, Johannes Liebl, Sebastian Sitzberger

    Interferometric measurement of highly accurate flat surfaces

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

    2016

    DOI: 10.1117/12.2235525

    Abstract anzeigen

    The most important part in manufacturing precision optics is a reliable measurement procedure which provides results a few times more accurate than the quality to be produced. In general two specific values are important, the repeatability of several measurements which are done in a row and the absolute accuracy which is mostly defined by the systematical error of the measurement device. The repeatability can be improved relatively simple, by increasing the number of measurements and a following averaging step. To increase the absolute accuracy of a measurement device in the field of precision optics is far more challenging. In this paper several interferometer absolute testing methods to measure flat surfaces are compared. The main objective was to name a value for the achievable accuracy. Therefor four different methods were analyzed: 1. The three flat test, a method which is already used several decades to determine the quality of a flat surface. As a result, two absolute measured profiles, horizontal and vertical, can be calculated. 2. The multi rotation test, an extension of the classical three flat test. The big advantage of this method is a fully three dimensional map of the systematical error. 3. The systematical error calculated by the SSI-A. Hereby several subapertures are measured over the whole surface. The redundant information’s of the overlapping regions can be used to calculate the systematical error of the system. 4. The rotation of the transmission flat relatively to the interferometer. Thereby the rotation unsymmetrical errors can be calculated and subtracted. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Rolf Rascher, Sebastian Sitzberger

    An investigation on the efficiency of the manufacturing of components in precision optics

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

    2016

    DOI: 10.1117/12.2236137

    Abstract anzeigen

    By adaption and coordination of successive process steps the efficiency of producing optics can be improved. In the beginning of this investigation, the focus is on two crucial process steps of the optical manufacturing process. First, there is the optical and mechanical design of the optical part and system. In this context, it is important to consider what modifications compared to the current standard design are possible respectively useful. Thus, the modifications will only concentrate on parts of the optic that do not interfere with the optical functionality. Furthermore in this part of the study the main aspect is the clamping situation of the optical part in a holder or an optical system. It will be discussed, whether it is useful to add special clamping surfaces respectively a clamping flange in contrast to the standard design. The faultless functioning of the optics has always first priority. Second, the manufacturing process itself has a great number of single steps. Therefore, a main part of the research is the investigation of current clamping situations in optics manufacturing, with prospect to improve them in order to work perfectly with the design modifications, as mentioned above. This part of the investigation focuses on the clamping system for the lens on each machine necessary for manufacturing. In the scope of this paper the authors want to summarize characteristics and deficits of current clamping systems and workpiece mounts and give a prospect of the following course of action. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

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

    Dependency between removal characteristics and defined measurement categories of pellets

    Proceedings of SPIE 9573

    2015

    ISBN: 978-1628417395

    DOI: 10.1117/12.2189987

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Zeitschriftenartikel

    Heiko Biskup, Rolf Rascher, Christian J. Trum

    Stabilität im Polierprozess

    Newsletter Bayern Photonics (Innovationsnetzwerk Optische Technologien), no. Oktober

    2015

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Heiko Biskup, Rolf Rascher, Alexander Haberl

    Surface errors in the course of machining precision optics

    Proceedings of SPIE Volume 9575, Optical Manufacturing and Testing XI (Aug 27th 2016, San Diego, CA)

    2015

    DOI: 10.1117/12.2189991

    Abstract anzeigen

    Precision optical components are usually machined by grinding and polishing in several steps with increasing accuracy. Spherical surfaces will be finished in a last step with large tools to smooth the surface. The requested surface accuracy of non-spherical surfaces only can be achieved with tools in point contact to the surface. So called mid-frequency errors (MSFE) can accumulate with zonal processes. This work is on the formation of surface errors from grinding to polishing by conducting an analysis of the surfaces in their machining steps by non-contact interferometric methods. The errors on the surface can be distinguished as described in DIN 4760 whereby 2nd to 3rd order errors are the so-called MSFE. By appropriate filtering of the measured data frequencies of errors can be suppressed in a manner that only defined spatial frequencies will be shown in the surface plot. It can be observed that some frequencies already may be formed in the early machining steps like grinding and main-polishing. Additionally it is known that MSFE can be produced by the process itself and other side effects. Beside a description of surface errors based on the limits of measurement technologies, different formation mechanisms for selected spatial frequencies are presented. A correction may be only possible by tools that have a lateral size below the wavelength of the error structure. The presented considerations may be used to develop proposals to handle surface errors. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    J.-P. Richters, Felix Friedke, Rolf Rascher, Thomas Stubenrauch, Johannes Liebl, Engelbert Hofbauer

    The vignetting field stop procedure: A new physical measurement principle for the Deflectometric acquisition of big Optical Surfaces - DaOS

    DGaO Proceedings (116. Jahrestagung in Brno, Tschechische Republik, 25.-29.05.2015)

    2015

    NachhaltigAngewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Christine Wünsche, Rolf Rascher, Patrick Schäfer

    Quantification of synthetic lens surface characteristics by an optical measurement system as stylus instrument

    Proceedings of SPIE 9442

    2015

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    S. Sinzinger, Christian Vogt, Rolf Rascher

    A Study on Elastic Grinding Tools

    Proceedings of the International Optical Design Conference, Washington, DC

    2014

    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 Wirtschaftsingenieurwesen

    Zeitschriftenartikel

    Christine Wünsche, Heiko Biskup, Rolf Rascher, Sebastian Draxinger, Johannes Liebl

    Process developement fort the reproducible roughness measurement of optical surfaces using white light interferometry

    International Journal of Metrology and Quality Engineering (EDP Sciences), vol. 5, no. 1, pp. 29-35

    2014

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    O. Fähnle, Christine Wünsche, Heiko Biskup, Rolf Rascher, E. Langenbach, F. Frost, A. Schindler, Johannes Liebl

    Generation and field testing of roughness reference samples for industrial testing of surface roughness levels below 0.5nm Sq

    Proceedings of EOSAM 2014 (European Optical Society Annual Meeting) [Sep 15-19 2014, Berlin, Germany]

    2014

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    S. Schleich, Felix Friedke, Rolf Rascher, C. Zöcke, Thomas Stubenrauch, K. Wühr, B. Pastötter, Engelbert Hofbauer

    3D-optical measurement system using vignetting aperture procedure

    Proceedings of SPIE Vol. 9132

    2014

    DOI: 10.1117/12.2052631

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Christian Vogt, Rolf Rascher, Florian Schneider

    Grinding Processes for Silicon Carbide (CSiC) Materials

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

    2013

    ISBN: 978-0-9566790-2-4

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Roland Maurer, Rolf Rascher, Thomas Stubenrauch, et al., Johannes Liebl, Engelbert Hofbauer

    Approach to the measurement of astronomical mirrors with new procedures

    Optical Metrology 2013, Optical Measurement Systems for Industrial Inspection VIII, volume 8788

    2013

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Beitrag (Sammelband oder Tagungsband)

    Christine Wünsche, Heiko Biskup, Roland Maurer, Rolf Rascher, Christian J. Trum

    Determination of a suitable parameter field for the active fluid jet polishing process

    Optifab 2013, vol. Volume 8884

    2013

    ISBN: 9780819497475

    DOI: 10.1117/12.2028752

    Abstract anzeigen

    In 2012 a well-known company in the field of high precision optics assigned the University of Applied Sciences Deggendorf to determine a suitable parameter field for the active fluid jet polishing (AFJP) process in order to reach a surface accuracy of at least lambda / 5. The active fluid jet polishing is a relatively new and an affordable sub-aperture polishing process. For a fast and precise identification of the parameter field a considered design of experiment is necessary. The available control variables were the rotational speed of the nozzle, the distance between the test object and the jet, the feed rate, the material of the pin inside the nozzle and the material of the test object itself. In order to reach a significant data density on the one hand and to minimize the number of test runs on the other hand a meander shaped tool path was chosen. At each blank nine paths had been driven whereby at each path another parameter combination was picked. Thus with only one test object nine parameter settings may be evaluated. For the automatized analysis of the tracks a software tool was developed. The software evaluates ten sections which orthogonally intersect the nine tracks on the test-lens. The significant measurement parameters per section are the width and the height of each path as well as the surface roughness within the polished tracks. With the aid of these parameters and further statistical evaluations a suitable parameter field for the goal to find a constant and predictable removal spot was determined. Furthermore up to now over 60 test runs have been successfully finished with nine parameter combinations in each case. As a consequence a test evaluation by hand would be very time-consuming and the software facilitates it dramatically.

    Angewandte Naturwissenschaften und WirtschaftsingenieurwesenMaschinenbau und Mechatronik

    Beitrag (Sammelband oder Tagungsband)

    Christine Wünsche, Roland Maurer, Rolf Rascher, Florian Schneider

    Calculation of the reference surface error by analyzing a multiple set of sub-measurements

    SPIE Optics + Photonics 2013, Optical Manufacturing and Testing X, volume 8838

    2013

    DOI: 10.1117/12.2024003

    Abstract anzeigen

    In the field of precision optics the interferometry is the most applied measurement method to test spherical and flat objects. In principle, a standard interferometer setup is limited to these surface geometries, but interferometric systems may be modified with the aid of CGH’s or the stitching technology. As a consequence aspherical shapes and even freeform optics are measurable up to a certain extent. In an interferometric measurement the measured variable is the optical path difference (OPD) between the reference wave and the test wave. Based on the detected OPD the surface error of the test object is calculated by phase shifting methods for instance. It is evident, that the error from the reference surface affects the determination of the test object surface error. One option to face this problem is the calibration of the system prior to the measurement. For this the determination of the reference surface error may be realized with the aid of a two sphere test or a random ball test e.g. [1]. In the well-known SSI-technology from QED technologies the reference surface error is calculated on the basis of the sub-measurements. Due to the self-calibrating nature of the QED stitching principle [2-4] a calibration of the system prior to the measurement is not necessary. The University of Applied Sciences Deggendorf has implemented a similar algorithm to estimate the reference wave front error, or to be exact the error of the whole optical system, based on a multiple set of sub-measurements. This paper describes the applied algorithm in detail and discusses the results. To verify the implemented tool the results are compared to the outcomes of the QED stitching software. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

    Angewandte Naturwissenschaften und Wirtschaftsingenieurwesen

    Zeitschriftenartikel

    Christine Wünsche, Rolf Rascher, Christian Schopf

    Rauhigkeitsmessungen an großen und schwer zugänglichen Bauteilen

    MM Industriemagazin-Maschinenmarkt, no. 47, pp. 40-41

    2013