New results from the Precessions polishing process scaled to larger sizes

D. D. Walker, A. T.H. Beaucamp, D. Brooks, V. Doubrovski, M. Cassie, C. Dunn, R. Freeman, A. King, M. Libert, G. McCavana, R. Morton, D. Riley, J. Simms

Research output: Contribution to journalConference article

36 Citations (Scopus)

Abstract

The Precessions process uses an inflated membrane-tool that delivers near-Gaussian polishing spots. The tool-motion over the part can be constructed to preserve an aspheric form whilst removing damage from preceding processes, or control the form through a tool-path prescribed by numerical optimization. The process has previously been validated on surfaces up to 200mm diameter and used extensively in industrial environments. In this paper we report the first trials on a substantially larger part - a 500mm diameter f/1 ellipsoidal mirror - as part of the UK's technology-development for Extremely Large Telescopes. We draw attention to subtle problems that have arisen along the way. We also report on developing the process for free-form surfaces, in contrast to the axially-symmetric parts worked hitherto. The paper concludes with an assessment of the lessons learnt from the experiments, as they may impact on realization in a practical ELT segment fabrication facility.

LanguageEnglish
Pages71-80
Number of pages10
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume5494
DOIs
Publication statusPublished - 24 Sep 2004
Externally publishedYes
EventOptical Fabrication, Metrology, and Materials Advancements for Telescopes - Glasgow, United Kingdom
Duration: 24 Jun 200425 Jun 2004

Fingerprint

Polishing
precession
polishing
Extremely Large Telescopes
Telescopes
Tool Path
Free-form Surface
Numerical Optimization
Mirrors
telescopes
mirrors
membranes
damage
Membranes
Fabrication
Mirror
fabrication
optimization
Membrane
Damage

Cite this

Walker, D. D. ; Beaucamp, A. T.H. ; Brooks, D. ; Doubrovski, V. ; Cassie, M. ; Dunn, C. ; Freeman, R. ; King, A. ; Libert, M. ; McCavana, G. ; Morton, R. ; Riley, D. ; Simms, J. / New results from the Precessions polishing process scaled to larger sizes. In: Proceedings of SPIE - The International Society for Optical Engineering. 2004 ; Vol. 5494. pp. 71-80.
@article{00f2dec452a64c4dac5ae2ef87cc7d84,
title = "New results from the Precessions polishing process scaled to larger sizes",
abstract = "The Precessions process uses an inflated membrane-tool that delivers near-Gaussian polishing spots. The tool-motion over the part can be constructed to preserve an aspheric form whilst removing damage from preceding processes, or control the form through a tool-path prescribed by numerical optimization. The process has previously been validated on surfaces up to 200mm diameter and used extensively in industrial environments. In this paper we report the first trials on a substantially larger part - a 500mm diameter f/1 ellipsoidal mirror - as part of the UK's technology-development for Extremely Large Telescopes. We draw attention to subtle problems that have arisen along the way. We also report on developing the process for free-form surfaces, in contrast to the axially-symmetric parts worked hitherto. The paper concludes with an assessment of the lessons learnt from the experiments, as they may impact on realization in a practical ELT segment fabrication facility.",
author = "Walker, {D. D.} and Beaucamp, {A. T.H.} and D. Brooks and V. Doubrovski and M. Cassie and C. Dunn and R. Freeman and A. King and M. Libert and G. McCavana and R. Morton and D. Riley and J. Simms",
year = "2004",
month = "9",
day = "24",
doi = "10.1117/12.553044",
language = "English",
volume = "5494",
pages = "71--80",
journal = "Proceedings of SPIE - The International Society for Optical Engineering",
issn = "0277-786X",
publisher = "SPIE",

}

Walker, DD, Beaucamp, ATH, Brooks, D, Doubrovski, V, Cassie, M, Dunn, C, Freeman, R, King, A, Libert, M, McCavana, G, Morton, R, Riley, D & Simms, J 2004, 'New results from the Precessions polishing process scaled to larger sizes', Proceedings of SPIE - The International Society for Optical Engineering, vol. 5494, pp. 71-80. https://doi.org/10.1117/12.553044

New results from the Precessions polishing process scaled to larger sizes. / Walker, D. D.; Beaucamp, A. T.H.; Brooks, D.; Doubrovski, V.; Cassie, M.; Dunn, C.; Freeman, R.; King, A.; Libert, M.; McCavana, G.; Morton, R.; Riley, D.; Simms, J.

In: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 5494, 24.09.2004, p. 71-80.

Research output: Contribution to journalConference article

TY - JOUR

T1 - New results from the Precessions polishing process scaled to larger sizes

AU - Walker, D. D.

AU - Beaucamp, A. T.H.

AU - Brooks, D.

AU - Doubrovski, V.

AU - Cassie, M.

AU - Dunn, C.

AU - Freeman, R.

AU - King, A.

AU - Libert, M.

AU - McCavana, G.

AU - Morton, R.

AU - Riley, D.

AU - Simms, J.

PY - 2004/9/24

Y1 - 2004/9/24

N2 - The Precessions process uses an inflated membrane-tool that delivers near-Gaussian polishing spots. The tool-motion over the part can be constructed to preserve an aspheric form whilst removing damage from preceding processes, or control the form through a tool-path prescribed by numerical optimization. The process has previously been validated on surfaces up to 200mm diameter and used extensively in industrial environments. In this paper we report the first trials on a substantially larger part - a 500mm diameter f/1 ellipsoidal mirror - as part of the UK's technology-development for Extremely Large Telescopes. We draw attention to subtle problems that have arisen along the way. We also report on developing the process for free-form surfaces, in contrast to the axially-symmetric parts worked hitherto. The paper concludes with an assessment of the lessons learnt from the experiments, as they may impact on realization in a practical ELT segment fabrication facility.

AB - The Precessions process uses an inflated membrane-tool that delivers near-Gaussian polishing spots. The tool-motion over the part can be constructed to preserve an aspheric form whilst removing damage from preceding processes, or control the form through a tool-path prescribed by numerical optimization. The process has previously been validated on surfaces up to 200mm diameter and used extensively in industrial environments. In this paper we report the first trials on a substantially larger part - a 500mm diameter f/1 ellipsoidal mirror - as part of the UK's technology-development for Extremely Large Telescopes. We draw attention to subtle problems that have arisen along the way. We also report on developing the process for free-form surfaces, in contrast to the axially-symmetric parts worked hitherto. The paper concludes with an assessment of the lessons learnt from the experiments, as they may impact on realization in a practical ELT segment fabrication facility.

UR - http://www.scopus.com/inward/record.url?scp=10444220319&partnerID=8YFLogxK

U2 - 10.1117/12.553044

DO - 10.1117/12.553044

M3 - Conference article

VL - 5494

SP - 71

EP - 80

JO - Proceedings of SPIE - The International Society for Optical Engineering

T2 - Proceedings of SPIE - The International Society for Optical Engineering

JF - Proceedings of SPIE - The International Society for Optical Engineering

SN - 0277-786X

ER -