Study of ultra-precision diamond turning of a microlens array with a fast tool servo system

2006 ◽  
Author(s):  
S. To ◽  
T. C. Kwok ◽  
C. F. Cheung ◽  
W. B. Lee
Keyword(s):  
Servo System ◽  
Microlens Array ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Ultra Precision

scholarly journals Measurement and Compensation of Tool Contour Error Using White Light Interferometry for Ultra-Precision Diamond Turning of Freeform Surfaces

2020 ◽  
Vol 14 (4) ◽  
pp. 654-664 ◽  
Author(s):  
Kodai Nagayama ◽  
◽  
Jiwang Yan
Keyword(s):  
White Light ◽  
High Efficiency ◽  
Diamond Tool ◽  
Microlens Array ◽  
Diamond Turning ◽  
Contour Error ◽  
Form Accuracy ◽  
Freeform Optics ◽  
Ultra Precision ◽  
Quick Measurement

In ultra-precision diamond turning of freeform optics, it is necessary to obtain submicron-level form accuracy with high efficiency. In this study, we proposed a new method for the quick measurement and compensation of tool contour errors to improve the form accuracy of the workpiece. In this method, the nanometer-scale contour error of a diamond tool is quickly and precisely measured using a white light interferometer and then compensated for, before machining. Results showed that the contour of a diamond tool was measured with an error less than 0.05 μm peak-to-valley (P-V) and the feasibility of error compensation was verified through cutting experiments to create a paraboloid mirror and a microlens array. The form error decreased to 0.2 μm P-V regardless of the contour error of the diamond tools when cutting the paraboloid mirror, and that of the microlens array was reduced to 0.15 μm P-V during a single machining step.

scholarly journals Fabrication of Sinusoidal Microstructures on Curved Copper Surface by Ultra-Precision Diamond Cutting with a Rotary B-Axis and Fast Tool Servo System

2021 ◽  
Vol 11 (21) ◽  
pp. 10302
Author(s):  
Xuesen Zhao ◽  
Haiping Du ◽  
Wenda Song ◽  
Qiang Zhang ◽  
Zhenjiang Hu ◽  
...  
Keyword(s):  
Tool Path ◽  
Servo System ◽  
Copper Surface ◽  
Curvature Radius ◽  
Machining Accuracy ◽  
Machining Parameters ◽  
Fast Tool Servo ◽  
Diamond Cutting ◽  
Sinusoidal Modulation ◽  
Ultra Precision

While curved surface microstructures have wide applications in optical components and devices, how to achieve high machining accuracy of the microstructures is crucial for their applications. In the present work, we fabricate sinusoidal modulation microstructures on a curved copper surface by ultra-precision diamond cutting, with the combination of a rotary B-axis and a fast tool servo system. Specifically, tool path planning, together with the consideration of a curved, sinusoidal surface meshing and tool tip arc segmentation compensation, is carried out. Preliminary cutting experiments are firstly carried out on a homemade four-axis ultra-precision lathe, which demonstrates the advantages of additionally applying the rotary B-axis in suppressing burr formations and over-cutting phenomenon over the sole utilization of the fast tool servo system. Subsequent experiments are carried out to evaluate the effects of feed rate and the number of sampling points on the machining accuracy of the microstructures under the combination of a rotary B-axis and a fast tool servo system. With the optimized machining parameters, sinusoidal modulation microstructures, which have a wavelength of 700.6 μm, a peak-to-valley of 18.7 μm, a surface roughness of 18.9 nm and a deviation of profile tolerance of 4.326 μm, are successfully fabricated on a curved copper surface with a face radius of 10 mm and a curvature radius of 500 mm.

Freeform machining of ophthalmic toric lens mould using fast tool servo-assisted ultra-precision diamond turning process

2020 ◽  
pp. 251659842093974
Author(s):  
Ishan Anand Singh ◽  
Gopi Krishna S. ◽  
T. Narendra Reddy ◽  
Prakash Vinod
Keyword(s):  
Surface Roughness ◽  
Single Point ◽  
Measurement Data ◽  
Surface Profile ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Toric Surface ◽  
Machined Surface ◽  
Ultra Precision ◽  
A Minor

This research aims to establish a methodology for machining of toric lenses, using fast tool servo-assisted single point diamond turning and to assess the generated surface for its characteristics. Using the established mathematical model, toric surface is explained to understand the geometry and to generate the parameters required for fast tool servo machining. A toric surface with a major diameter of 18.93 mm and a minor diameter of 15.12 mm has been cut on the intelligent ultra-precision turning machine (iUPTM). The surface profile and surface roughness were measured. After analysing the measurement data of the machined surface, on two perpendicular axes of the toric lens, form accuracy of 0.49 µm peak-to-valley (PV), and surface roughness of 12 nm in Ra, 4–8 nm in Sa are obtained. From the experimental results obtained, it can be concluded that the proposed method is a reasonable alternative for manufacturing toric lens mould.

Turning of Micro-Structured Surfaces Based on a Fast Tool Servo System

2014 ◽  
Vol 684 ◽  
pp. 308-312 ◽  
Author(s):  
Xiao Hui Wang ◽  
Zhi Ding ◽  
Yu Zhen Ma
Keyword(s):  
Piezoelectric Actuator ◽  
Closed Loop ◽  
Tracking Error ◽  
Servo System ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Precision Engineering ◽  
Loop Control ◽  
Structured Surfaces ◽  
Grid Surface

A fast tool servo system is developed for the fabrication of micro-structured surface on a diamond turning machine. The fast tool servo (FTS) system in this investigation employs a piezoelectric actuator to actuate the diamond tool and a capacitance probe as the feed back sensor. To compensate the inherent nonlinear hysteresis behavior of the piezoelectric actuator, Proportional Integral (PI) closed loop control with a feed-forward predictor is implemented. The result of closed loop experiment in FTS demonstrates that the tracking error has been reduced to a level of less than 150nm. Actual experiment of fabricating the sinusoidal grid surface was performed on an ultra-precision diamond turning machine designed by Center of Precision Engineering of HIT. The fabrication of a sinusoidal grid surface has indicated the effectiveness of the fabrication system.

A Study of Tool Path Generation for Machining of Precision Roller with Wavy Patterned Microstructures by Slow Tool Servo

2016 ◽  
Vol 679 ◽  
pp. 191-197
Author(s):  
Ling Bao Kong ◽  
Chi Fai Cheung ◽  
Wing Bun Lee ◽  
Suet To ◽  
Su Juan Wang ◽  
...  
Keyword(s):  
Tool Path ◽  
Single Point ◽  
Research Work ◽  
Axial Direction ◽  
Diamond Turning ◽  
Machining Process ◽  
Fast Tool Servo ◽  
Roller Surface ◽  
Ultra Precision ◽  
Slow Tool Servo

Embossing by patterned rollers is one of the most efficient machining approaches for manufacturing plastic films with patterned microstructures, and the precision roller with patterned microstructures is the key tooling component in the roll-to-roll process. Single-point diamond turning with a slow or fast tool servo is an enabling and efficient ultra-precision machining process to fabricate microstructures through a simple process to achieve optical surface finish directly. Most of the current studies on slow or fast tool servo machining processes either focus on face machining of patterned microstructures, or on tool servo machining of microstructures in the radial direction of precision rollers. Relatively little research work is found in relation to machining patterned microstructures on a precision roller by using the tool servo in the axial direction. This paper presents a pilot study on the development of a tool path generator for machining precision rollers with wavy patterned microstructures by using slow tool servo machining in the axial direction on a precision roller. The machining mechanism is firstly explained, based on which the tool path generator is developed for machining wavy patterned microstructures on a precision roller surface. Preliminary experimental work was conducted to study the generation of wavy patterned microstructures on a precision roller using a four-axis ultra-precision machine. The machined wavy microstructures on the roller surface are measured and analyzed to successfully validate the performance of the proposed tool path generator.

Research on Mathematical Models of New Diamond Turning for Non-Axisymmetric Aspheric Mirrors

2007 ◽  
Vol 364-366 ◽  
pp. 35-38 ◽  
Author(s):  
Cheng Shun Han ◽  
Long Jiang Zhang ◽  
Shen Dong
Keyword(s):  
High Resolution ◽  
Mathematical Models ◽  
Diamond Tool ◽  
Diamond Turning ◽  
Fast Tool Servo ◽  
Aspheric Surfaces ◽  
Nc Program ◽  
Ultra Precision ◽  
Diamond Turning Machines ◽  
New Generation

In this paper, a new generation method for diamond turning non-axisymmetry aspheric mirrors is introduced. A rotary arm that carried a diamond tool combined with fast tool servo was used to replace the straight guides employed by most diamond turning machines. The micro linear feed of the fast tool servo was real-time calculated with the use of high resolution angular feedback on the work spindle and the swing tool. Synchronized motion of the fast tool servo according to rotating angles of the workpiece and the diamond tool produced ultra-precision non-axisymmetry aspheric surfaces. The corresponding mathematical models of NC program are presented.

Tri-axial Fast Tool Servo Using Hybrid Electromagnetic-Piezoelectric Actuation for Diamond Turning

2021 ◽  
pp. 1-1
Author(s):  
Zi-Hui Zhu ◽  
Li Chen ◽  
Yuhan Niu ◽  
Xiaonan Pu ◽  
Peng Huang ◽  
...  
Keyword(s):  
Diamond Turning ◽  
Piezoelectric Actuation ◽  
Fast Tool Servo

scholarly journals Research on surface quality difference of Microlens array fabricated by fast tool servo cutting

2021 ◽  
pp. 1-1
Author(s):  
Yuetian Huang ◽  
Shijie Li ◽  
Jin Zhang ◽  
Chen Yang ◽  
Yingxiu Kong ◽  
...  
Keyword(s):  
Surface Quality ◽  
Microlens Array ◽  
Fast Tool Servo ◽  
Quality Difference
Sign in / Sign up

Export Citation Format

Share Document