TELESCOPE MIRROR GRINDING & POLISHING
xx TELESCOPE MIRROR
How to grind, polish and test an aluminum mirror. SCIENTIFIC AMERICAN Nov 1963 (v.209#5) pg. 159
How to purify abrasives used in grinding and polishing the objective mirror for a reflecting telescope to avoid scratches. SCIENTIFIC AMERICAN Oct 1969 (v.221#4) pg. 136
A compact short focus telescope with spherical optical features. Tips on grinding and polishing the five optical surfaces. Primary mirror is 4-1/4" in diameter. SCIENTIFIC AMERICAN Aug 1972 (v.227#2) pg. 110
How to cut the channels in a pitch lap by using a heated steel rod. SKY & TELESCOPE Aug 1978 (v.56#2) pg. 155
Mirror making class at Macalester College (St.Paul, Minn.) uses four specific goals to assure that students are successful in grinding a usable telescope mirror. The goals are described and the results of various Foucault tests are illustrated, along with the corrective action necessary. SKY & TELESCOPE Sep 1978 (v.56#3) pg. 249
A simple test to determine if a telescope mirror has been fully polished prior to aluminizing. Also includes a tip on elutriating or washing polishing rouge. SKY & TELESCOPE Aug 1979 (v.58#2) pg. 180
Plans for building a Hindle-type grinding machine for large mirrors (16" to 20"). SKY & TELESCOPE Oct 1979 (v.58#4) pg. 367
Tip: Make your own mold for pitch lap channels from paper and silicon cement. SKY & TELESCOPE Jan 1980 (v.59#1) pg. 79
How to perforate a 22" mirror with an 8" hole using a simple jig and a Hindle-type grinding machine. SKY & TELESCOPE May 1980 (v.59#5) pg. 427
Tip: Use a Teflon-coated waffle iron to embed the channels into a warm pitch lap. SKY & TELESCOPE Nov 1980 (v.60#5) pg. 437
Convert a pulley-driven clothes dryer into a mirror grinding machine. Grind mirrors up to 14" diameter. Est. cost: $30. SKY & TELESCOPE Mar 1981 (v.61#3) pg. 260
Saga of a 24" reflector. Includes photograph of a homebuilt grinding machine, plus tips on grinding and mounting in a Dobsonian-style telescope. SKY & TELESCOPE Jul 1981 (v.62#1) pg. 74
Tip: Use steel water pipe as a plug cutter when drilling a hole in a telescope mirror. SKY & TELESCOPE Jan 1982 (v.63#1) pg. 89
Make a silicone-rubber mold to cast a pitch lap. SKY & TELESCOPE Nov 1983 (v.66#5) pg. 454
Tips on making large-diameter, lightweight, honeycomb mirror blanks of Pyrex by fusing in an electric kiln, such as those used for pottery. SKY & TELESCOPE Jul 1984 (v.68#1) pg. 71
A new method for making a pitch lap by covering the curved grinding tool with a uniform layer of thin pitch tiles. SKY & TELESCOPE Sep 1984 (v.68#3) pg. 264
Build inexpensive mirror grinding tools by laminating disks from thin glass sheets. SKY & TELESCOPE Oct 1984 (v.68#4) pg. 359
Tip: Construct mirror-making tools from thin glass and thick plaster. SKY & TELESCOPE Jan 1985 (v.69#1) pg. 75
Some modifications to a Hindle-type grinding machine. SKY & TELESCOPE Mar 1985 (v.69#3) pg. 267
A safe way to separate a mirror and tool which have "seized together" during fine grinding. SKY & TELESCOPE Sep 1987 (v.74#3) pg. 317
Tips on making the mirror and corrector plate for an 8" Schmidt camera from common plate glass. SKY & TELESCOPE Jun 1989 (v.77#6) pg. 664
Reflections of a telescope maker. Tips on (1) making an 8" diameter f/4 short-focus mirror, (2) using a curved diagonal-carrying arm, (3) eliminating a conventional mirror cell, and (4) a tall Dobsonian-style mounting that rolls on two wheels and features a convenient eyepiece height. SKY & TELESCOPE Sep 1989 (v.78#3) pg. 313
Simple plywood platform fits on the corner of any sturdy table and lets you grind a telescope mirror while sitting down. SKY & TELESCOPE May 1992 (v.83#5) pg. 569
Finish your mirror by polishing with the same ophthalmic pads used by eyeglass makers. Final figuring is still done by pitch lap, but in much less time. SKY & TELESCOPE Jun 1992 (v.83#6) pg. 688
A versatile desktop optical polisher is based on the Elgin Optical Co. type of polishing machine. Two amateur-built versions are shown. Construction details are given for one. SKY & TELESCOPE Nov 1995 (v.90#5) pg. 81
Tip on using paper masks and a microwave oven to temporarily reshape a pitch lap to concentrate the polishing action on specific high zones. SKY & TELESCOPE Nov 1996 (v.92#5) pg. 87
Optimal polish for optimal optics. How to ensure your telescope mirror's surface is as good as it can get. Polishing practices, techniques and tips when making a telescope mirror. SKY & TELESCOPE May 2000 (v.99#5) pg. 135
Making pitch laps. TELESCOPE MAKING #1 Fall 1978 pg. 3
What's my abrasive? A table compares the grit number, diameter in thousandths of an inch, and the micron measurement of abrasives from eight different companies. TELESCOPE MAKING #2 Winter 1978 pg. 9
How to make your own channeled grinding tool for grinding telescope mirrors. The tool is made from small hexagon-shape ceramic tiles glued to a backing plate. TELESCOPE MAKING #6 Winter 1979-80 pg. 26
Correction TELESCOPE MAKING #8 Summer 1980 pg. 3
A portable lens and mirror grinding/polishing machine. Handles blanks up to 6" diameter. Spindle speeds are variable from 2- to 60-rpm. Powered by a 1/10 hp geared motor. TELESCOPE MAKING #7 Spring 1980 pg. 20
How to grind and test a 4" mirror with a 966" radius of curvature. The Foucault test involves reflecting the beam off of an optical flat in order to "fit" within the length of the basement being used. TELESCOPE MAKING #7 Spring 1980 pg. 30
Description of the Macalester College "Four goal system" for making a first telescope mirror. Includes extensive discussion of a Ronchi-type test, including three pages of photos showing test patterns for various mirrors. TELESCOPE MAKING #9 Fall 1980 pg. 18
Mirror curvature during grinding: A mathematical treatment. Calculates the amount of grinding time needed to "pull" the focal length down to a given distance. TELESCOPE MAKING #11 Spring 1981 pg. 20
Tip: Use patio stones as the base for tile tools when grinding large telescope mirrors. TELESCOPE MAKING #12 Summer 1981 pg. 3
Grinding, polishing and figuring thin telescope mirrors. Part 1. Grinding. TELESCOPE MAKING #12 Summer 1981 pg. 30
Grinding, polishing and figuring thin telescope mirrors. Part 2. Polishing. TELESCOPE MAKING #13 Fall 1981 pg. 36
Pyrex honeycomb mirrors. Tips on building a large mirror blank from bonded sheets of Pyrex glass. TELESCOPE MAKING #14 Winter 1981-82 pg. 24
A 20" thin mirror Dobsonian. Describes grinding of the mirror and construction of the mounting. TELESCOPE MAKING #14 Winter 1981-82 pg. 32
Tips on casting a telescope mirror blank. TELESCOPE MAKING #15 Spring 1982 pg. 5
Added Info TELESCOPE MAKING #22 Spring 1984 pg. 9
Added Info TELESCOPE MAKING #24 Fall 1984 pg. 45
Grinding, polishing and figuring thin telescope mirrors. Part 3. Figuring. TELESCOPE MAKING #16 Summer 1982 pg. 32
Notes on grinding and polishing an 8" achromatic objective lens. TELESCOPE MAKING #18 Winter 1982-83 pg. 5
Tip: New method for polishing mirrors. TELESCOPE MAKING #28 Fall 1986 pg. 53
A new wide-field all-spherical telescope. Includes design parameters for a 10" clear aperture. Tips on grinding and polishing the mirror and lenses, null testing the corrector, etc. TELESCOPE MAKING #30 Summer 1987 pg. 4
How controlling the acidity (pH) of pitch laps may impact the polishing of telescope mirrors. TELESCOPE MAKING #36 Spring 1989 pg. 37
Building a pseudo-automated mirror grinding machine. An evolved version of Brian Knight's grinding machine is combined with an electronic timer and a pump for the polishing slurry. TELESCOPE MAKING #38 Fall 1989 pg. 22
High-finesse figuring. Detailed instructions for transforming a spherical surface into an accurate paraboloid. TELESCOPE MAKING #39 Winter 1989-90 pg. 41
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