See the bevel 2 photos below. today=today.getTime()/10; Get Price Read More Mirror Grinding Machines telescope mirror grinding machine – Grinding Mill China Grinding and Testing a Telescope Mirror RASC St John s Centre You need special machinery to grind a mirror Indeed you do if you are going to use machinery at all The machinery must be made to mimic the human action Humans make … Next the big pulley was mounted in the center of the top of the frame. I started by mounting a 1 inch floor flange to the corner I I wrapped The collar will } from an 18 inch diameter tabletop and some scrap lumber. Then a slot was cut with my band saw to allow for locking the arm in place using a c-clamp. I also built another machine of the same They really do a Information for ATMs Zip archive of Mirror-o-Matic Yahoo Groups (2000-2019) 307 MB Contact Dennis Also I don't think it makes much difference what The 12 inch pulley is mounted on a long piece of 1/2 inch diameter shaft. everything in place. imagefront = ". I did it by using an In this view you can see how the c-clamp across the slot cut in the arm locks everything in place. This blade does make some chips on the the inside of the cut. A passage hole for the shaft was drilled in the center of the top surface. The position of the stroke can be adjusted The large circle only got it on one side and the edge, since only the top side and The blank would overhang the edge of the wood disk. Also a Hindle type machine for a southern firm to grind and polish and time consuming though. 2. Then the three pie-slice shaped pieces of wood are placed into the openings between the spokes of the pulley and screwed down to the large Instead of using multi-step pulleys to change speeds like the Mirror-O-Matic does, my machine will have infinitely variable speed at the turn of a dial. grinding drum will clean up the edge. Even going slowly and carefully to avoid making bad chips, the cutting process is really quite quick. I started with pre-made, thick, circular table-tops bought from The drums are hollow, and have holes to allow the cooling water to spray out on the work. is actually even easier to clean it with a wet-vac. elsewhere on this web site. [Email me] The motor control box has not yet been mounted, and can be seen on the seat of the chair to the right of the machine. stub of shaft protruding from the center of the turntable. A sturdy post is needed to mount the grinder arm on. The motor is only temporarily mounted at this point, held in place by the orange clamp. of the edge. … Bevelling is really easy. 8 Showing Lap & Mirror On the opposite, a shallow mirror (e.g. Dennis Rech's M-o-M designs finally inspired me to just get up and do it. M-o-M polishing a 16" mirror. Actually I go slowly, and only cut half-way through. It only took about a minute of running to get it this smooth. Yet, the larger the mirror you make the more money you can save when compared to buying a mirror already made. These are the spindle speeds and stroke rates I settled on, or should The 1/2 inch shaft rides in two pillow block bearings. document.write(imageback); fast for my liking. arm in position. I could find. Basically it is a pump sprayer. Here is a bottom view of the mounting for the turntable. { then hammered it in place. later for mounting a dam. The pulley was put in place and its set screw was tightened. Details of Stabalizer How I do it is explained One side of a large barn door hinge is mounted to the side of the arm. rpm. In this photo the control box has been mounted and wired to the motor, which has now been screwed in place. While it may be all right at slow spindle speeds, at the speed Other places to visit: [Back to Mike's Homepage] The grinder would grind the glass, but document.write(linkback); The bolts are long enough to go through the second bearing on the underside. I made my first mirror grinding and polishing machine over thirty years onto the other side of the hinge with a bolt through the hinge into the handle socket, and a couple of pipe clamps. telescope mirror grinding machines . see in commercial buildings. linkback = " target=\"blank\">"; I had the stroke faster than the spindle at first but changed it to On top of this I removed the set screw from the collar, I will try to remember to get some photos of the It will give your mirror its overall focal ratio. by Twyman for a 6" diameter block of lenses the speed should be 40 -50 This grinder is going to be getting a lot of work as I cast more and more mirror blanks in my kilns. Fig. 7. Though it is not shown in this photo, the nozzle gets mounted on the grinder arm so that the spray A long threaded eye-bolt passes through to carry them, and I have never seen them in a store. Polishing a mirror is one of the great joys you will experience as a maker and builder. The glass is secured to the tabletop with a few dabs of hot-melt glue. bearings would be mounted. After reading all I could find build a mirror grinding machine Grinding Mill China. bar. This provides a removable connection between the pulley and the wood circle. The tool is hanging over the mirror by 1/6 the diameter of the tool, or about 1/8 diameter of the mirror… Here is a close-up view of the edge after using the medium drum grinder on it. It is a set of tools that allow me to cut thick glass circles to size. the trigger on the grinder so it is always on. google_ad_height = 600; An extra plate of 3/4 inch wood was screwed to the underside of the top to beef up the area where the bearings, and their set screws were tightened down. 6. prevent vibration from working them loose when the grinder is running. If the disk needs to be chip free, I simply cut it a little oversize I salvaged this variable speed motor, control box and power cord from my old band saw after it broke. good quality dust mask is required. } octagons, so the corners don't interfere with the cutter arm. When I returned to telescope making I had to build another machine. 1. machine. Again, it was made out of scrap lumber and various and then grind down the edge to size (erasing the chips along the way) with the edge grinding attachment. They will provide the motive power for the turn table. I really only cut the rounded edge off of it so that it now has a square edge, which will be needed So it works. This machine and the polishing machine were fabricated from 1-1/2" square According to "Prism and Lens Making" number on glass. Along the front blade over the circle I want to cut, and crank the spinning cutter wheel down onto the rotating glass. [Mike's home-built jet engine page] of the machine is a bracket holding jars of carborundurn powders. slower. They are already curve-generated. minute and used this for grinding both 6 inch and 8 inch mirrors. Fig. document.writeln(adend); I like the fixed-post plan vs others with eccentric drives, because it gets the heavy grinding done in an automated manner, but still give you the chance to hand-figure. document.writeln(adbase); The 1/2 top of the pulley. I have built an accessory for the grinding table. was fitted to the spindle. In actual aluminum plate. I bought table-tops slightly larger in diameter The large circle is cut from a 20 inch diameter tabletop. only by gravity. document.write(rnd + count); By adjusting the swing of the eccentric to an amount that is slightly more than the diagonal of 1 pitch square we make sure that no ring zones are polished into the mirror. I didn't even The splash tray is made from a 15" diameter pizza tray. either way of centre over centre, A stabiliser bar holds the stroke adend = "

"; Fig. A c-clamp tightens the arm in place once it is positioned. It was made document.writeln(adstart); Finer and finer grits Rough indeed! type. blanks. Rough grinding. Before I did any more grinding though, I decided the edge of the glass needed to be bevelled, to prevent chipping. I obtained a 27 to 1 worm and wheel and built it into a reduction box. from the blank to be ground. The rough grinding drum very quickly got the edge trued up and round and to the correct diameter with a minimum quality dust mask is required. document.write(linkfront); of the center of a 16 inch diameter, 3/4 inch thick glass disk. The drums are designed for use on special A jet of cooling water was directed at the grinding drum at all times to prevent over-heating the glass and causing chips to spall out Without the water though, a lot of glass dust goes airborne, so a good I drilled a hole in the center of the large wood circle large enough for the 1 inch shaft collar to be a tight fit in it. yet. Mirror Grinding Machine posted in ATM, Optics and DIY Forum: I have some interest in building a grinding machine for possible up to an 18 mirror , but something that will also do a 6 or 8 mirror. { operation a 14 or 14.5 blank would be attached to this disk. Then a switch to a finer adbase= ""; There are lots of good ideas there. the base tile around the turntable and secured it in place with numerous short screws. A 1 inch diameter pulley on the motor drives a 12 inch pulley with the belt. Front view of top of F/D = 4) well suited for deep sky observations. I started the build by making a sturdy frame for the unit out of 2x4 lumber and 3/4 inch thick plywood. adstart = "

"; These diamond grinding    Plan view of drive arrangement. Update The smallest circle was cut to 12 inches in diameter for use in edging 12.5 inch diameter blanks. google_ad_slot = "2101760792"; Over the years, I'd been collecting motors, gear boxes, pulleys, etc. By slipping on and off a couple of belts, the machine can quickly be reconfigured for spinning work or for stroking work. len=30; Jun 15, 2016 - Homemade sphere machine constructed from angle iron, steel plate, electric motors, hinges, and reducers. So I decided to try using adhesive backed Velcro instead. on top of the pulley. Anyone building machinery for cold-working glass should have a look at the MOM web site and plans. Then a hole was drilled through the them to allow A 13.5 diameter wood disk has been installed on the grinder. With the Mirror on top, the tool on the bottom, and coarse grit in between, we start grinding with the mirror overhanging the tool. I drew concentric circles on the top of the tabletop in the sizes of common telescope mirror blank A flap of Velcro holds down The spray nozzle was removed to get this photo. The edge isn't terribly important, and I don't want to waste Much is also unchanged - mirror grinding techniques are very similar to those written up by Porter and Ingalls in the 20´s and 30´s. I have plans for the Mir O Matic but would like to do something a bit more modern. Here is a photo of the grinder in operation actually edging a 12.5 inch blank I cast in my kiln. document.write(rnd + count);    Ring zones on 12" mirror. Side view of drive arrangement. A stiff spring was added to pull the hinge closed. time and money making it beautiful. The long screw-eye passes through an embedded nut in the top wooden plate, and presses on the assembly below. I finished up using a spindle speed of 72 rpm. Holding Details The table tops were 8 mm. keep the large wood circle centered on the shaft. Here is a short video of a test of the turntable drive. and the stroke 80 -100 per minute. used peanut butter bottles. I say what I finished up with after the pulleys were made. can be used to further smooth out the edge. The grinder is controlled from a remote air valve in the air line. That is really messy It used the working principle of the machine illustrated at "A" Fig.3, Page 163, "Amateur Telescope Making" Book 1. The grinding operation will be messy, so it will need to be done outside. thread onto an ordinary angle grinder, and seem to work just fine with an external water spray. belt. I'm thinking that a thinner Many amateur astronomers still choose to fabricate their own instruments, for the pride of accom… None have been totally satisfactory. This makes it easily removable for cleaning. with industrial strength, adhesive-backed Velcro. Fig. Fig. hinge to allow for the curved profile of the grinder body. I had a 1/4HP 1350 rpm. I started construction of the arm to hold the grinder by gluing and screwing two short lengths of 2x4 together. I built a circle-cutting jig for my band saw and cut out some circular parts for the grinder. in edging 14 inch diameter blanks. Grinding & Polishing Machine. Polishing may be a different story. Grinding Machine for Large Telescope Mirrors I designed and built a grinding machine for mirrors up to 42 inches [1.1m] in diameter. wet grinders that can pump water into the drum. Enough of the shaft was left protruding above the top bearing that it would stick up 1.5 inches above the 3. drums have diamond bits brazed onto their surfaces. I wouldn't have even thought this was possible until I tried it. The 12 inch pulley is mounted on a long piece of 1/2 inch diameter shaft. I cut half way through from one side, then flipped it over and cut air-powered die grinder with a diamond blade, pressed against the spinning glass. In fact, I haven't cracked one the outside, and silicone caulk on the inside. Torque will be transmitted through the pie-shaped pieces of wood. //-->,

Click on a lady to learn how to meet her.