Grinding and polishing technology by computer controlled active lap for Φ1250mmF/1.5 aspheric mirror

Fan, Bin; Zeng, Zhige; Li, Xiaojin; Chen, Qiang; Gao, Pingqi; Zhou, Jiabin; Wan, Yong

doi:10.1117/12.883418

Cited by 2 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During processing, the lap could follow the shape of an aspheric surface under the control of 12 or more actuators, which makes the fabrication of large aspheric surfaces as easy as that of spheric surfaces. In the past decade, mirrors with 1.2-8.4 m diameter have been fabricated with high performance by using active stressed lap technology [1][2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Deformation verification and surface improvement of active stressed lap for 4 m-class primary mirror fabrication

Zhao

Fan

et al. 2015

Appl. Opt.

Self Cite

View full text Add to dashboard Cite

The surface shape accuracy of the active stressed lap impacts the performance of grinding and polishing in the fabrication of large mirrors. We introduce a model of active stressed lap for the fabrication of a 4 m f/1.5 mirror based on finite element analysis (FEA), and the lap surface accuracy achieves RMS<1.8 μm in the FEA method. Using the lap surface measurement system, experimental verification is put forward, and the RMS of the measured lap surface is within 2 μm in practice. A general improvement in lap surface accuracy using the Zernike polynomial is shown. After compensating the calculation errors, the lap surface accuracy is improved by 8%-23%, and achieves RMS<1.5 μm, which is appropriate for practical grinding and polishing.

show abstract

Section: Introductionmentioning

confidence: 99%

Deformation verification and surface improvement of active stressed lap for 4 m-class primary mirror fabrication

Zhao

Fan

et al. 2015

Appl. Opt.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The computer-controlled active lap (CCAL), which is based on a stressed lap, is an effective way to grind and polish the primary mirror for modern large or even huge telescopes [1][2][3][4][5][6][7]. In the active lap grinding or polishing process, the removed material on the mirror surface during unit time can be calculated based on the Preston equation [8], dzx; y k · Px; y · Vx; y · dt;…”

Section: Introductionmentioning

confidence: 99%

Study on active lap tool influence function in grinding 18 m primary mirror

Liu

Zeng

et al. 2013

Appl. Opt.

View full text Add to dashboard Cite

We present a theoretical modeling method to predict the ring tool influence function (TIF) based on the computer-controlled active lap process. The gap on the lap-grinding layer is considered, and its influence on the ring TIF is analyzed too. The relationship between the shape of the ring TIF and the lap-workpiece rotation speed ratio is discussed in this paper. The recipe for calculating dwell time for axisymmetric fabrication is discussed. The grinding process of a 1.8 m primary mirror is improved based on these results. The grinding process is accomplished after 30 circles of grinding, and the surface shape error is from PV 82 μm RMS 16.4 μm reduced to PV 13.5 μm RMS 2.5 μm.

show abstract

Grinding and polishing technology by computer controlled active lap for Φ1250mmF/1.5 aspheric mirror

Cited by 2 publications

References 0 publications

Deformation verification and surface improvement of active stressed lap for 4 m-class primary mirror fabrication

Deformation verification and surface improvement of active stressed lap for 4 m-class primary mirror fabrication

Study on active lap tool influence function in grinding 18 m primary mirror

Contact Info

Product

Resources

About