High-efficiency mirror grinding of single-crystal diamond substrate was investigated. • A rotary grinder with a #15000 diamond wheel was used for mirror grinding. • A record high removal rate (0.04 μm/min) was achieved. • The processed surface was ultrasmooth with ~0.1 nm average surface roughness.

Me starting my binoscope 400mm making. That is the grinding the backs of primary mirrors in Juny 2003 to planing it. Sorry for the small movie's problems at ...

The mirror (or tool) was then carefully placed on top of the tool (or mirror) and grinding started (i.e., pushing the glass disk on top back and forth). The procedure was quite similar to grinding a smaller mirror, except that the disks are heavier. With the coarser grits, pressure was applied to speed grinding.

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 spray bottle). Sprinkle on Grit.

Gordon Waite shows some steps during fine grinding of the 20" mirror. As the grind progresses through the grades of abrasives, see the technique Gordon uses...

With the Mirror on top, the tool on the bottom, and coarse grit in between, we start grinding with the mirror overhanging the tool. We rub the center of mirror against the edge of the tool, and this wears a depression in the center of the mirror (the edge of the tool wears down also, so that the tool becomes convex (a "hill" in the center) and ...

Here is a stack of my home-made 8 and 10 inch mirror blanks. The second from the bottom is the one above. I can use the thinner blank below it as the grinding tool. UPDATE I have started rough grinding one of my home-made 10in glass blanks. Here is an action shot of …

10 Inch Mirror Blanks, 3/4" Thick: $55 + S&H (16);Shipping prices are to the USA - not shipping outside the US, sorryCombined shipping is possible - Write. For a complete mirror making KIT, with all abrasives, polishing compounds, pitch, and grinding tool included, please see our Buy Telpe Mirror Kits website for great prices on plate glass ...

Answer (1 of 5): The record for largest telpe made the same way amateurs use today goes to Ireland's Lord Rosse, who in 1845 built a 72-inch-telpe. Mirror grinding How the Enormous Mirrors on the World's Largest Telpe Are Made Liquid mirror telpe - Wikipedia This guy a truck d...

It is not a robot, but just a pattern of polishing. For big aperture though, spinning a large mirror and moving a large polisher might be too much work. That is why the mirror lab spun caste their glass to avoid hogging, and then had a robot go around grinding and polishing the high spots. Or maybe they spun ground it.

in the 2001-02 Stellafane Mirror Class. Fine grinding refines the basic shape you have ground into the surface of the glass with rough grinding. The sequence of ever finer grits that you use smoothes the rough surface that was made in rough grinding, and prepares you for polishing. You are also refining the shape of the surface to be a section ...

When grinding thin mirror blanks, be conscious of downward pressure, which if excessive, may bend the mirror blank momentarily out of shape. While this is not a problem during rough grinding (as the amount of flex is exceedingly small) the effect becomes important as you reach the later stages of making your telpe mirror.

Me, grinding a 8" mirror for a telpe. Using a 1/3 tool on top stroke w/ 240 grit SiC

Fine grinding: I change from my rough grinding area to my fine grinding and polishing area after 220, not before. #220 is still gritty stuff. The "W" stroke: This is a casual way of describing any stroke that goes forward and backward while progressing left to right or right to left on the mirror.

Placing the mirror face up and grinding with a moderate "W" stroke will also move the curve toward the edge, and tends to produce a more spherical surface. Leaving the mirror grossly hyperbolic will make fine grinding difficult. Fine Grinding . We've all heard stories about fine grinding taking hundreds of …

Page 1 of 4 - Grinding a 6 inch Mirror - posted in ATM, Optics and DIY Forum: Hey Everyone, I first made a 6 f/10 telpe back in 2002. It was, as everyone called it here the minimum size you should make. So I went ahead with it. The f/10 was because some gentleman had ground the glass to f/10 and abandoned it in the local astronomy club and the president of which handed to me.

My Mirror Grinding Machine. For a long time I've wanted to build a machine for grinding telpe mirrors. Dennis Rech's M-o-M designs finally inspired me to just get up and do it. Over the years, I'd been collecting motors, gear boxes, pulleys, etc. Most of them came from industrial junk yards.

Then after grinding the mirror face with 220 grit, cleanup thoroughly and flash polish by polishing for 15 minutes. Don't go onto finer grits until the astigmatism is gone. The second is to identify the saddle orientation, and using a sub-diameter lap, locally polish the ends of the saddle.

Grinding a 6 inch [15cm] mirror to F/2.8 using a ring tool. Mirror Making Zen. Do one thing at a time. Mirror making is a process: 1. Get blank, grit, pitch 2. Roughly grind a curve in the mirror face 3. Refine the curve with diminishing grit sizes 4. Polish the mirror face 5. Parabolize the mirror face

Grinding Machine for Large Telpe Mirrors. I designed and built a grinding machine for mirrors up to 42 inches [1.1m] in diameter. By slipping on and off a couple of belts, the machine can quickly be reconfigured for spinning work or for stroking work. The machine can also work smaller mirrors if the drip pan is moved to the fast shaft on ...

The process for grinding telpe mirrors at home actually doesn't look too much different than when Isaac Newton first developed it, and he didn't have any power tools. John Dobson was a monk and did much of his work in secret from his brotherhood.

Grinding Mirrors. Silver backing chips very easily so use the finest grit grinder head you can get – super fine if possible. Alternatively, use an old grinder head which is dulled already. If you use a coarse grit it will chip into the mirror backing; Keep the backing uppermost to …

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 …

Page 3 of 4 - Grinding a 6 inch Mirror - posted in ATM, Optics and DIY Forum: You don't test the mirror till it's fully polished, period. this is what they taught at Delmarva Mirror Making and there were hundreds of mirrors over the years, all made in a 3 day weekend. in 3 days. From pre-generated curve grinding 80 grit to 1/8~ figured finished mirror.

Grinding Machines Mirror-o-matic Tom Waineo's Desktop Grinding/Polishing Machine Ken Lilja's Grinding Machine. TELPE MAKING – David Ratledge's Virtual Home. A telpe with a Schmidt corrector is a Schmidt … Secondary Mirror. … Even with a …

Welcome Guys..please do like👍 share🔁 and subscribe and press the bell icon 🔔

Mechanical assembly is complete. The machine could start grinding now. I still need to build the electronics, and then there's painting and finishing.

Grinding an 8″ F/10 Telpe Mirror. For this project (my first time ever grinding a mirror) I ordered an 8″ Black Vitrified Ceramic (BVC) blank without a pregenerated curve from ASM Products in Ste-Basile PQ. Ordering from Canada is always cheaper once you factor in all the taxes – all told the kit cost about $185.

A mirror mount is needed to hold the mirror during testing. If the mirror is a 'thin' mirror (i.e. the thickness is much less than 1/8th its diameter) then the mount must hold the mirror without deforming it. The weight of the glass can deform a thin mirror. In my case, I was making a full-thickness mirror, which is a mirror whose thickness is 1/8th the diameter or more, so mirror deformation ...

For large thin mirrors, say 12 inches [30cm] or greater and 1.5 inches [4cm] or thinner, the mirror back must be ground flat, or at least regular in shape before beginning fine grinding the mirror's face. Cast a tool specifically for the mirror's back, and grind with 220 grit, inspecting for low unground spots. Grind until they disappear.

1/4 λ is on the order of 0.000006in. My Son who is a qualified milspec machinist doesn't get closer than 0.0001in. I suppose you could rough grind the tool and initial mirror shape but this will only work if you CNC router is 3D.

How to grind a mirror blank into the well-figured basis for a Dobsonian telpe. How to grind the glass, how to carry out a focus test, how to polish with ...

Page 1 of 2 - Grinding your own mirror - How is it possible to get accuracy in the nm? - posted in ATM, Optics and DIY Forum: So I have read forum questions & answers on topics such as whether it is possible to use a 3D printer to design and print out a telpe mirror, or design an array of paraboloids this way for a segmented design, and the answers have been, no, the 3D printers dont …