Fabrication of Freeform Optics in Ultra-Precision Raster Milling

2007 ◽  
Vol 339 ◽  
pp. 412-416 ◽  
Author(s):  
Su Juan Wang ◽  
Chi Fai Cheung ◽  
Sandy To ◽  
Wing Bun Lee
Keyword(s):  
Tool Path ◽  
Research Work ◽  
Tool Path Generation ◽  
Path Generation ◽  
Machining Parameters ◽  
Generation System ◽  
Primary Interest ◽  
High Productivity ◽  
Freeform Optics ◽  
Ultra Precision

Recently, the high quality and high productivity in fabrication of freeform optics has been of primary interest in manufacturing industries, such as die and mould manufacturing, aerospace part manufacturing, and so forth. However, the fabrication of freeform optics is currently expensive and vastly complex. Ultra-precision raster milling can produce non-rotational symmetric surfaces with sub-micrometric form accuracy and nanometric surface finish without the need for any subsequent post polishing. While, there is little research work focus on this kind of machining method. This paper presents a framework of a tool path generation system for freeform surface ultra-precision raster milling. This system includes model of freeform optics, tool path generator, interference monitor and an optimization model of machining parameters. The tool path generation system can generate interference free and optimal tool path for machining freeform surfaces. Some simulation results have been presented to illustrate the performance of the system.

Study of The Tool Path Generation Method of an Ultra-Precision Spherical Complex Surface Based on a Five-Axis Machine Tool

2021 ◽  
Author(s):  
Tianji Xing ◽  
Xuesen Zhao ◽  
Zhipeng Cui ◽  
Rongkai Tan ◽  
Tao Sun
Keyword(s):  
Surface Roughness ◽  
Tool Path ◽  
Spherical Surface ◽  
Tool Path Generation ◽  
Path Generation ◽  
Tool Paths ◽  
Spherical Surfaces ◽  
Spherical Complex ◽  
Ultra Precision ◽  
Five Axis

Abstract The improvement of ultra-precision machining technology has significantly boosted the demand for the surface quality and surface accuracy of the workpieces to be machined. However, the geometric shapes of workpiece surfaces cannot be adequately manufactured with simple plane, cylindrical, or spherical surfaces because of their different applications in various fields. In this research, a method was proposed to generate tool paths for the machining of complex spherical surfaces based on an ultra-precise five-axis turning and milling machine with a C-Y-Z-X-B structure. Through the proposed tool path generation method, ultra-precise complex spherical surface machining was achieved. First, the complex spherical surface model was modeled and calculated, and then it was combined with the designed model to generate the tool path. Then the tool paths were generated with a numerically controlled (NC) program. Based on an ultra-precision three-coordinate measuring instrument and a white light interferometer, the machining accuracy of a workpiece surface was characterized, and t[1]he effectiveness of the provided tool path generation method was verified. The surface roughness of the machined workpiece was less than 90 nm. Furthermore, the surface roughness within the spherical region appeared to be less than 30 nm. The presented tool path generation method in this research produced ultra-precision spherical complex surfaces. The method could be applied to complex spherical surfaces with other characteristics.

Tool path generation for ultra-precision polishing of freeform optical surfaces in an off-axis three-mirror imaging system

2015 ◽  
Vol 231 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Dengpeng Huang ◽  
Lei Zhang ◽  
Shijun Ji ◽  
Ji Zhao
Keyword(s):  
Tool Path ◽  
Imaging System ◽  
Concentric Circle ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Path Generation ◽  
Freeform Surfaces ◽  
Primary Mirror ◽  
Tool Paths ◽  
Ultra Precision

The optical performance of the off-axis three-mirror imaging system can be greatly improved using freeform surfaces. This article focuses on the polishing of the primary mirror and tertiary mirror in an off-axis three-mirror imaging system. The primary mirror and tertiary mirror are fabricated on one monolithic substrate and described by non-uniform rational B-spline–based freeform surfaces. The separated and integrated polishing strategies are presented for polishing the two mirrors on the four-axis computer numerical control polishing platform. A tool path generation approach is proposed for polishing of the non-uniform rational B-spline–based freeform surface. Three kinds of the tool paths are given for ultra-precision polishing of the primary mirror and tertiary mirror with the freeform surfaces. The concentric circle path and the approximately concentric circle path are generated for polishing two mirrors separately, while the spiral path is calculated for integrated polishing of two mirrors simultaneously. The polishing tool posture along the planned tool paths is also analyzed. The ultra-precision polishing experiments of the primary mirror and tertiary mirror on the four-axis computer numerical control polishing platform are performed to verify the proposed approach for tool path generation.

scholarly journals Adaptive Spiral Tool Path Generation for Diamond Turning of Large Aperture Freeform Optics

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 810 ◽  
Author(s):  
Dongfang Wang ◽  
Yongxin Sui ◽  
Huaijiang Yang ◽  
Duo Li
Keyword(s):  
Tool Path ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Surface Generation ◽  
Machining Efficiency ◽  
Path Generation ◽  
Control Points ◽  
Large Aperture ◽  
Freeform Optics ◽  
Slow Tool Servo

Slow tool servo (STS) diamond turning is a well-developed technique for freeform optics machining. Due to low machining efficiency, fluctuations in side-feeding motion and redundant control points for large aperture optics, this paper reports a novel adaptive tool path generation (ATPG) for STS diamond turning. In ATPG, the sampling intervals both in feeding and cutting direction are independently controlled according to interpolation error and cutting residual tolerance. A smooth curve is approximated to the side-feeding motion for reducing the fluctuations in feeding direction. Comparison of surface generation of typical freeform surfaces with ATPG and commercial software DiffSys is conducted both theoretically and experimentally. The result demonstrates that the ATPG can effectively reduce the volume of control points, decrease the vibration of side-feeding motion and improve machining efficiency while surface quality is well maintained for large aperture freeform optics.

scholarly journals Tool path generation of ultra-precision diamond turning: A state-of-the-art review

2019 ◽  
Vol 2 (3) ◽  
pp. 118-124 ◽  
Author(s):  
Hu Gong ◽  
Shengjun Ao ◽  
Kuntao Huang ◽  
Yi Wang ◽  
Changya Yan
Keyword(s):  
Tool Path ◽  
State Of The Art ◽  
Tool Path Generation ◽  
Diamond Turning ◽  
Path Generation ◽  
Ultra Precision

Study on Tool-Path Generation for Ultra-Precision Machining of Optical Lens Array

2012 ◽  
Vol 516 ◽  
pp. 595-599
Author(s):  
Kui Liu ◽  
Pei Ling Liu ◽  
Hu Wu ◽  
Kah Chuan Shaw
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
Tool Path Generation ◽  
Numerical Control ◽  
Precision Machining ◽  
Path Generation ◽  
Software Platform ◽  
Optical Lens ◽  
Lens Array ◽  
Ultra Precision

In this study, a computer numerical control (CNC) programming software platform for ultra precision machining of optical surfaces was developed based on an MS Windows application framework and openGL. Using cylindrical coordinates, the tool path can be generated based on the polar angle, radius and a linear coordinate of the Z-axis, as well as cutting tool nose radius compensation. A 3D simulation based on tool path generation was developed for machining verification, which largely reduces the oscillation of the machine during the ultra precision machining process. Ultra precision machining of an optical lens array was carried out on a 5-axis ultra precision machining centre using a single crystalline diamond cutter. The experimental results indicated that the oscillation effect can be largely reduced using the cutting tool path using a super steady machining strategy. This software platform is designed as a framework, where the capability and functions can be expanded by adding in more freeform surface packages.

scholarly journals Automated Unsupervised 3D Tool-Path Generation Using Stacked 2D Image Processing Technique

2019 ◽  
Vol 3 (4) ◽  
pp. 84
Author(s):  
Tadele Belay Tuli ◽  
Andrea Cesarini
Keyword(s):  
Tool Wear ◽  
Tool Path ◽  
Closed Form Solution ◽  
Tool Path Generation ◽  
Image Processing Technique ◽  
Depth Of Cut ◽  
Path Generation ◽  
Machining Parameters ◽  
Machining Time ◽  
G Code

Tool-path, feed-rate, and depth-of-cut of a tool determine the machining time, tool wear, power consumption, and realization costs. Before the commissioning and production, a preliminary phase of failure-mode identification and effect analysis allows for selecting the optimal machining parameters for cutting, which, in turn, reduces machinery faults, production errors and, ultimately, decreases costs. For this, scalable high-precision path generation algorithms requiring a low amount of computation might be advisable. The present work provides such a simplified scalable computationally low-intensive technique for tool-path generation. From a three dimensional (3D) digital model, the presented algorithm extracts multiple two dimensional (2D) layers. Depending on the required resolution, each layer is converted to a spatial image, and an algebraic analytic closed-form solution provides a geometrical tool path in Cartesian coordinates. The produced tool paths are stacked after processing all object layers. Finally, the generated tool path is translated into a machine code using a G-code generator algorithm. The introduced technique was implemented and simulated using MATLAB® pseudocode with a G-code interpreter and a simulator. The results showed that the proposed technique produced an automated unsupervised reliable tool-path-generator algorithm and reduced tool wear and costs, by allowing the selection of the tool depth-of-cut as an input.

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