Rough Grinding Mirror

31 行· Rough Grinding The first milestone is putting a curve into the mirror face. The curve's depth dictates the mirror's focal length. The curve should be spherical. Creating the curve can be done by several methods: The curve is ground into the mirror face using a grinding tool. The curve is pre-generated for you.

07-03-2010· This video shows how to setup a mirror grinding machine for fixed-post grinding, also known as spin grinding or spinning. After setup, you'll see how abrasiv...

23-09-2012· After hogging the mirror blank to depth, the rough grinding stage begins. In this video I am grinding with 60/90 grit. The wets are lasting about 90 seconds ...

15-12-2014· Rough Grinding of a Telescope Mirror. 15 Monday Dec 2014. Posted by gfbrandenburg in History, Telescope Making ≈ Leave a comment. Tags. Hogging, Rough Grinding (Part two of my description of the essential steps in making a telescope) 2.

For rough grinding a 6" mirror, about 1/2 teaspoon of grit is used per wet. With finer grits, proportionately less grit is used per wet. Grits in the25 micron range are often premixed with water to form a slurry, and water and grit are squirted onto the work together from a plastic squeeze bottle (not a …

Previously in rough grinding we deepened the center of the mirror's face either by grinding with coarse grit and a tool, slumping in a kiln over a mold, or purchasing the glass pre-generated. During fine grinding, we'll grind the mirror face against a tool with a series of ever finer grits.

Thin mirrors are hard to work with for a first-timer. Ultralights are typically faster than f/5. Making a sub-f/5 primary as your first mirror is difficult - I know because I basically did it (I abandoned a 6" f/8 halfway through polishing when I chipped it so my 6" f/4.5 was my first experience in figuring).

15-12-2014· Rough Grinding of a Telescope Mirror. 15 Monday Dec 2014. Posted by gfbrandenburg in History, Telescope Making ≈ Leave a comment. Tags. Hogging, Rough Grinding (Part two of my description of the essential steps in making a telescope) 2.

The rough grinding usually digs a depression in the center of the upper disc which gradually deepens and spreads toward the edge of the disc. It is a fairly simple matter, by regulating the extent of overhand, to arrange to have the curve on the mirror face reach its proper depth just as the edge of the ground out area reaches the edge of the blank.

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Thin mirrors are hard to work with for a first-timer. Ultralights are typically faster than f/5. Making a sub-f/5 primary as your first mirror is difficult - I know because I basically did it (I abandoned a 6" f/8 halfway through polishing when I chipped it so my 6" f/4.5 was my first experience in figuring).

13-07-2014· Help ! rough grinding 16" mirror - posted in ATM, Optics and DIY Forum: Hello, Grinding a 16 blank, plate glass....I am currently 5/8 - 3/4 from the outside edge using a ring tool (7.5 lb. barbell plate, by hand) around a 55 gallon drum. I would like to get 1/4, or 1/8 from the edge, if possible. Any tips or tricks ??? Prayers ??? ...

Rough Grinding. Rough grinding (hogging out) is the first stage of grinding performed on a new flat blank and tool. The purpose of rough grinding is to generate a ‘dish’ in the center of the mirror. This dish is deepened until the correct radius of curvature (R.O.C.) is produced.

The Grinding Guru takes a few strokes on my mirror "It's not bad," he says After a few hours of this, I get my first taste of what this work is all about. We take my mirror outside and reflect an image of the sun onto a piece of paper. I see a white round disc with clearly-imaged clouds rapidly moving across the …

A good starter size is the 150 mm (6") mirror. A 200mm (8") will also work. Most ATM books and websites recommend a Pyrex® mirror blank, but in my opinion, annealed plate glass is better for this first, "learn and practice" mirror.It is cheaper, it is softer and grinds faster, needing less abrasives and with these small sizes, the low expansion glass like Pyrex has no practical (visible at ...

For hand grinding, the coarse grit sequence of 40, 60 , 80, 120, 220 is typical (start at the grit size appropriate for your mirror diameter as given in the section above). Silicon Carbide is used almost exclusively. Fine grit sequences vary more, and are often adjusted based on the supplies at hand.

Here's the plate glass tool (top) and mirror (bottom) during grinding. The blanks rest on a ~1/2 inch thick layer of newspaper to provide even support. . I had the mirror rough ground to an F/8 curve at the factory to save time. With a curve already generated, I did not have to start with 60 or 80 grit.

The rough grinding usually digs a depression in the center of the upper disc which gradually deepens and spreads toward the edge of the disc. It is a fairly simple matter, by regulating the extent of overhand, to arrange to have the curve on the mirror face reach its proper depth just as the edge of the ground out area reaches the edge of the blank.

A good starter size is the 150 mm (6") mirror. A 200mm (8") will also work. Most ATM books and websites recommend a Pyrex® mirror blank, but in my opinion, annealed plate glass is better for this first, "learn and practice" mirror.It is cheaper, it is softer and grinds faster, needing less abrasives and with these small sizes, the low expansion glass like Pyrex has no practical (visible at ...

Rough Grinding . Once you have the back of the mirror ground flat through 220 and the face reasonably flat, you're ready to start roughing the curve into the mirror. I recommend #60 carborundum for rough grinding. By the way, as in all optical work, be sure that you always maintain bevel on the edge of the mirror throughout grinding.

13-07-2014· Help ! rough grinding 16" mirror - posted in ATM, Optics and DIY Forum: Hello, Grinding a 16 blank, plate glass....I am currently 5/8 - 3/4 from the outside edge using a ring tool (7.5 lb. barbell plate, by hand) around a 55 gallon drum. I would like to get 1/4, or 1/8 from the edge, if possible. Any tips or tricks ??? Prayers ??? ...

Rough Grinding. Rough grinding (hogging out) is the first stage of grinding performed on a new flat blank and tool. The purpose of rough grinding is to generate a ‘dish’ in the center of the mirror. This dish is deepened until the correct radius of curvature (R.O.C.) is produced.

The Grinding Guru takes a few strokes on my mirror "It's not bad," he says After a few hours of this, I get my first taste of what this work is all about. We take my mirror outside and reflect an image of the sun onto a piece of paper. I see a white round disc with clearly-imaged clouds rapidly moving across the …

26-09-2006· Grinding and polishing your own mirrors is a long, arduous process. Instead of lapping the blank by hand, Laurie Hall built this mirror grinding machine from scratch.

08-06-2020· What grinding tool - posted in ATM, Optics and DIY Forum: I plan on ordering supplies to make my first mirror. Thinking an 8 f/6 From doing a bit of reading and watching the Dobson video, it seems that the tool used for rough grinding is *another* glass blank (the tool goes convex while grinding the mirror concave). So am I looking at ordering two 8 mirror blanks?

Here's the plate glass tool (top) and mirror (bottom) during grinding. The blanks rest on a ~1/2 inch thick layer of newspaper to provide even support. . I had the mirror rough ground to an F/8 curve at the factory to save time. With a curve already generated, I did not have to start with 60 or 80 grit.

How to Make Your Own Telescope Mirror: [Fig 1] This is a large piece of glass a woman off Craigslist gave me. It was 40"x40" and 0.75" thick. Its what I decided to use to make the mirror. Cutting it into smaller sections can be difficult but scoring it with a glass cutter and tapping the…