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Materials and Equipment | Astronomy Telescope

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Chapter 3. Materials and Equipment. He materials and equipment which are needed to produce the mirror are:. A 6-inch pyrex mirror blank, from Corning Glass Co., Corning, N. Y. The sides of a pyrex blank are tapered, giving to one surface a slightly larger diameter than the other. The larger surface is the one that is to be ground to curve for the mirror. A 6-inch plate-glass disk, of a thickness at least 1/8the diameter, from any plate-glass manufacturer. This is to serve as the tool. Emery, a variety of...

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The Mounting | Astronomy Telescope

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Chapter 14. The Mounting. Veryone is more-or-less familiar with the surveyor’s transit, in which two axes at right angles to each other enable the telescope to be aimed at any point in the celestial dome. Its motions are one in azimuth, about the perpendicular axis, and one in altitude, about the horizontal axis. The names of these motions have been combined in the term. Mounting, taking its name from the great circle basic to this system of co-ordinates, the celestial equator. Fig 70. Pipe mount (fi...

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The Paraboloid | Astronomy Telescope

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Chapter 7. The Paraboloid. The dotted curves in Fig. 35 represent the paraboloidal surfaces that could be obtained from the same spherical mirror by the three methods. At. Fig 35. Three methods whereby a sphere may be altered into a paraboloid. In each case, the graph at the left shows the departure, in millionths of an inch, of the paraboloidal surface from the same 6-inch f/8 mirror. Are identical amounting in the case of a 6-inch f/8 mirror to 11.4 millionths of an inch. Of the mirror’s center z...

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Mirror Grinding | Astronomy Telescope

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Chapter 4. Mirror Grinding. T is assumed that a cellar or other room in which the temperature is fairly constant is available. Grinding, even polishing, might be done almost anywhere, but testing and figuring can be carried on only under conditions of uniform temperature. Fig 22. The long stroke formerly used in rough grinding. The lengths of the strokes at the disposal of the mirror maker are described with reference to the diameter of the mirror or tool. A. How the Curve Is Obtained. The foregoing is a...

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The Paraboloid #2 | Astronomy Telescope

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Chapter 8. The Paraboloid #2. Or lie within the recommended tolerances. The value of the mask for the.70-per-cent zone is questionable, but so many beginners feel that it is beneficial in enabling them better to grasp the fundamentals of the test that its use is suggested. Formula for the edge zones, but failing to conform at the 70-per-cent zone. Fig 40. Testing the paraboloid at its focus with the aid of an aluminized optically flat mirror. Fig 39. Obviously, if the latter shape is seen on the mirr...

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Aluminizing and Cleaning | Astronomy Telescope

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Chapter 16. Aluminizing and Cleaning. It may be of interest to record the condition of three aluminized mirrors figured by the author, which have been giving excellent performance. When mirror. Variations in the thicknesses of their respective films were demonstrated. Neon light is practically useless for this diagonal test, for the almost overpowering reflection from the aluminized surface makes the interference bands so faintly discernible that one may falsely conclude that some contamination prohibits...

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Tube Parts Alignment The Finder | Astronomy Telescope

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Chapter 11. Tube Parts Alignment The Finder. With a 9/32″ or 5/16″ drill to permit free movement over the stove bolts. Drill holes in the angle clips with a No. 12 drill, and elongate them slightly with a small round file. The clips are fastened to the corners of triangle. Fig 57. Mirror cell parts, and assembled cell. The cell is held in the tube by the three 1″ screws, entering triangle. 8221; in diameter. Above: How angle brackets are attached to wooden blocks. Learn how to make your own telescope.

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Setting Circles Equatorial Adjustment | Astronomy Telescope

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Chapter 17. Setting Circles Equatorial Adjustment. The cardboard circles will render good service for a time if protected from the weather, but the construction of a more permanent set should be attempted while you are learning how to use the first ones. Experience with the cardboard circles may prove that half-degree graduations are not necessary. Adjustment of the Tube. Adjustment of the Polar Axis. From page 550 of the 1947. Take out the following data on Polaris’ culmination:. Variation in 3 days.

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The Pitch Lap | Astronomy Telescope

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Chapter 5. The Pitch Lap. Fig 27. Channeled lap. Fig 28. The molded lap. At left is the perforated rubber mat centered on the fine-ground face of the mirror, ready for the pitch to be poured. At right is a finished lap. Fig 29. The pattern of the mat for a 6″ lap, with ” perforations. Vertical lines are spaced 7/32″ apart. Figures at the right indicate separations between horizontal arcs (straight lines will do as well) in 64ths of an inch. Learn how to make your own telescope. 1 Story of the Telescope.

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Donate to astronomytelescope.nett | Astronomy Telescope

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Donate to astronomytelescope.net. I want to spend my time directly helping people, like you, by creating and maintaining this website. I do this because it’s a passion of mine with that said, it’s not cheap running a website these days. So, if you found this website useful, help me keep this site going and free just by donating 3 dollars. Every bit helps! To make a donation via PayPal, credit card, or e-check, please click the button below:. Thank you for your support and encouragement! 5 The Pitch Lap.