The tool is hanging over the mirror by 1/6 the diameter of the tool, or about 1/8 diameter of the mirror, and is fixed in this position. The motor turns the mirror and the differential rotation enables the grit and water to grind away at the mirror and tool neutrally, meaning the ROC isn't changing. You go through the grits this way.
DetailsThe M-o-M is a marvellous machine due to its simplicity and yet refined design. It is extremely flexible accommodating mirror sizes from 4 inch up to 20 inch (with slight modifications) and can be used for all three steps necessary in producing a mirror. That is you can use it to grind, polish and figure your optics.
DetailsGrinding Machines A Mirror-O-Matic Machine. 20" Mirror-O-Matic by Atila; 24" Machine by Bill; Automatic Cerium Stirring; Computerized Mirror Making Group; Drapier Grinding Machine; Fine Grinding a 20" by Gordon; Grinding & Polishing Machine by Ted; Grinding Machine by Tom; Grinding Machines by GAP47; Horizontal Lapping Wheel Plans; How To Use A ...
DetailsFinally had a chance to move to finer grinding compound. I'm very impressed with how much manual labor can be taken out of making a mirror with a grinding machine. The methods used here are from Gordon Waites youtube videos that area available for all to see.
DetailsRe: Building a fixed post mirror grinding machine. Update summary: Lots of work to get to this point. Things I need to probably change or fix: My gearing of the DC motor. I will need a slow speed for polishing (5 rpm), and faster speeds for hogging out and fine grinding (15- 30 rpm), so likely need to think about adding a gear reduction.
DetailsRough grinding. This step is about making one side of the glass concave. It will give your mirror its overall focal ratio. If you make the centre deep, you will end up with a fast telpe (e.g. F/D = 4) well suited for deep sky observations. On the opposite, a shallow mirror (e.g. F/D = 8) will be performing very well on planets and the moon.
DetailsMaking a Mirror takes Hundreds of Hours of Work. Not True! A 6" or 8" mirror should take about 40 to 80 hours of effort. While this is a non-trivial amount of time, the mirror can be completed in a few months, and certainly within a year. Most people work one to three hours a day on their mirror about one or two times a week.
DetailsAn alternative, which seems very popular with home machine builders, involves rotating the mirror at a relatively high speed whilst the tool has minimal movement or is fixed (as in the case of Gordon W's machine). The trick is to place a correctly sized tool in the appropriate position to ensure an even grind/polish.
DetailsA 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 …
DetailsPage 1 of 2 - Mirror grinding machine-runout - posted in ATM, Optics and DIY Forum: I am in the process of making a fixed post mirror grinding machine, big enough for a 20 inch mirror. I have now got the motor, pulleys, two shafts and turntable all together and working. The turntable rotates at around 25 rpm,which I think should be OK. If I put a dial indicator on …
DetailsAfter fine grinding is complete, the mirror must be polished. It is during polishing that you "figure" the mirror by using a different polishing stroke to change the mirror's spherical polished shape into a parabolic polished shape . See a related tutorial nearby titled, " Making A Mirror Polishing And Figuring Tool ".
DetailsBasically there are two types of grinding/polishing machine. The 'traditional' type which involves the mirror rotating at a relatively slow speed, a few rpm for a big mirror (16-20 inches) with the tool moving across the mirror, from side to side, at a higher rpm depending on the size of the mirror and/or tool.
DetailsBefore starting machine grinding and polishing, one should at least read several books on mirror making. Most of these books will be about hand work, but knowledge of calculating and measuring a sagitta, pouring pitch laps, building tile tools, and most importantly reading and interpreting the Ronchi and Foucault tests are extremely important.
DetailsJoined: 01 Aug 2013. Posted 12 September 2013 - 10:59 AM. Very few people are using glass tools these days, and big mirrors are often "generated" using simple diamond grinding wheels, there's no need for "CNC" at the rough grinding stage. Tools are commonly made from plaster and tiles.
DetailsProducts/Services for Parabolic Mirror Grinding Machines. Grinders and Grinding Machines - (987 companies) Grinders and grinding machines use an abrasive that is bonded to a wheel, belt or disc to remove material and improve surface finish. Devices can be pneumatically driven or powered by a combustion engine or electric motor.
Detailsand so his custom mirror grinding machine had a sort of "kinematic mount" where only 3 rollers. (2 on one side and 1 on the other) took all the load. out of the 21 or so that should have been evenly loaded.. and it still ground a 27" mirror to better than 1/4th wavelength. 11-16-2021, 04:43 AM #7.
DetailsUS suppliers of Mirror Blanks, Grinding & Polishing Supplies, and Telpe Making Supplies. Astronomy Clubs Many can offer help with your project. Astronomy Conventions & Star Parties A good place to look at various telpes and chat with their owners. Mirror Making Courses & …
DetailsI started this thread to record my building progress of a new mirror grinding and polishing machine. This machine will be capable of handling mirror sizes up to 22". I have decided that 22" is the absolute maximum otherwise becomes too cumbersome to move around. I have won 2 x 1/3 horse power single phase electric motors on eBay, at $45 each.
DetailsMirror-o-Matic was designed to be a very low cost astronomical mirror grinding, polishing and figuring machine. Its attributes are: 1. It can be built for somewhere between $200 and $400. 2. It is constructed of hardware store items and it needs no machined parts. 3. It is constructed primarily of 3/4 inch plywood and has few close tolerances. 4.
DetailsTelpe mirror grinding machine Mirror making and optical testing … The images below show the completed grinding machine in it's new garage in October 2001. GrindingPolishingMachine – LCAO. Telpe Making. Telpe Mirror Grinding and Polishing Machine. After I had made the 41-cm telpe mirror by hand I had decided that I needed a ...
DetailsA course diamond grinding drum is installed on the grinder. It will be used to take off the rough edges, and make blanks truly round. Then a switch to a finer grinding drum will clean up the edge. The edge grinder is done! Here I am doing a dry run to make sure everything works. A 13.5 diameter wood disk has been installed on the grinder.
DetailsAmazon: Glass Sander tip Sand Paper, Sandpaper, Sander Sheets 120 to 3000 Assorted Grit Sanding paper, 9 x 3.6 Inch Wet Dry Fine Grit Sandpaper for Wood, Plastic, Glass, Metal Sanding and Automotive Polishing 42 PCS. 4.6 out of 5 stars. 1,270.
DetailsRe: Building a fixed post mirror grinding machine. I I had a nice piece of 3/4" stainless dowel that was begging to be used. So I bought a cheap pillow block to provide the locator for the metal dowel, and then drilled the overarm to fit. These pillow blocks are $8 and come complete with a locking collar - great deal.
DetailsPage 2 of 5 - Making a Mirror grinding & Polishing machine - posted in ATM, Optics and DIY Forum: The machine I made is just driven by a drill press and pulley system. Variable speeds could be nice, but so far this system has worked. The turntable goes about 40 RPM for spin grinding and polishing, which works quite well. I can add a reduction and the …
DetailsMirror grinding machine construction log I started thinking about building my own mirror grinding machine several years ago. Having been on the ATM list now since almost the beginning of it here on the web, I had lots of of inspiration reading …
Detailsorbital mirror polishing machine LPC 160 MIRROR is suitable also for grinding and surface preparation prior to mirror polishing. Machine is delivered complete with Inverter device for an optimal mirror finishing Browse Grinders and Grinding Machines Datasheets for …
DetailsGrits & Pitch. Grits and Polishing Compound are the consumables in the mirror making process. Grits, typically of Silicon Carbide or Aluminum Oxide, in various grades, are used as an abrasive between the mirror and tool to grind the glass. Pitch is used to make a soft, conforming pitch lap for polishing and figuring. It is used with a Polishing Compound such as Cerium Oxide, which …
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