Click here if you are having trouble logging into the forums Cloudy Nights - Official Forums of the 2009 International Year of Astronomy Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User   You are not logged in. [Login] Entrance · Main Index · Search · New user · Who's Online FAQ · Calendar Equipment Discussions >> ATM, Optics and DIY Forum Previous   Index   Next   Flat   Indianajones member Reged: 09/16/07 Posts: 25 Re: 26" thin mirror, anyone?       07/01/08 06:02 PM Edit   Reply   Quote   Quick Reply:   Hi, I apologize for not responding to the questions several of you had posted. I wanted to wait to have the blank in my hands before answering!I finally took delivery of the blank this morning, and I'm pretty impressed at the sheer size. For those with more expertise at discerning the type of glass, the color seems to be a silvery grey. I'll try to answer the questiions I've been asked: 1. Perhaps I should have tried a 6" mirror first, but the price for this mirror was irresistible, costing what a 6" pyrex blank would have! 2. Grinding machine: I've asked help from the local astronomy club. I find out if they have a machine, otherwise I'll build one myself. I've got to put that Mechanical Engineering Masters Degree to some use sooner or later! 3. This mirror was used in an optical comparator, so I'm guessing it should be optically flat, it ground on the back and coated on the front although the coating's seen better days. 4. I'm considering an 18 point mirror cell for the support although that could change. I'm not planning on starting the grinding process immediately, got a 10" f/4.73 telescope to assemble! By the way, how would I get the existing coating off this mirror? (It's a flat mirror that I'd like to grind to a f/5 to f/6.) A big thank you to everyone who pipped in with their comments, you've helped me look at this problem from more than one angle. Clear skies IJ Post Extras       Entire thread Subject Posted by Posted on 26" thin mirror, anyone? Indianajones 06/22/08 07:38 PM Re: 26" thin mirror, anyone? Stadius   06/22/08 07:58 PM Re: 26" thin mirror, anyone? Indianajones   06/22/08 08:00 PM Re: 26" thin mirror, anyone? helpwanted   06/24/08 09:50 PM Re: 26" thin mirror, anyone? ken scharf   06/24/08 10:26 PM Re: 26" thin mirror, anyone? greenglass   06/24/08 10:39 PM Re: 26" thin mirror, anyone? Dick Parker   06/24/08 11:38 PM Re: 26" thin mirror, anyone? HiggsBoson   06/25/08 12:03 AM Re: 26" thin mirror, anyone? tatarjj   06/25/08 11:29 AM Re: 26" thin mirror, anyone? sixela   06/25/08 03:49 PM Re: 26" thin mirror, anyone? ken scharf   06/27/08 11:41 AM Re: 26" thin mirror, anyone? Indianajones   07/01/08 06:02 PM Don't touch that flat! mark cowan   07/01/08 10:31 PM Re: Don't touch that flat! Indianajones   07/02/08 08:22 PM Re: Don't touch that flat! mark cowan   07/03/08 12:38 AM Re: Don't touch that flat! Indianajones   07/03/08 06:44 PM Re: Don't touch that flat! mark cowan   07/04/08 02:33 PM Re: 26" thin mirror, anyone? ken scharf   06/25/08 12:18 PM Extra information 3 registered and 4 anonymous users are browsing this forum. Moderator:  Don W, Joe Cipriano  Forum Permissions       You cannot start new topics       You cannot reply to topics       HTML is disabled       UBBCode is enabled Rating: Thread views: 718 Jump to *International Year of Astronomy 2009* -----   Global Coordination   Cornerstone Projects   Special Projects   Special Task Groups   Global Activities   National and Regional Activities   IYA 2009 in Africa   IYA 2009 in the USA*Announcements and News* -----   Cloudy Nights Announcements   Discussion of CN Articles, Reviews, and Reports   Beginners Forum   Celestial Events   Light Pollution*Equipment Discussions* -----   ATM, Optics and DIY Forum   Binoculars   Binoviewers   Cats & Casses   Classic Telescopes   Equipment   Eyepieces   Mounts   Observatories   Reflectors   Refractors    Celestron SkyScout and Meade mySky   Video and Electronically Assisted Astronomy*Astrophotography and Sketching* -----   Beginning Imaging   Film Astrophotography   DSLR & Digital Camera Astro Imaging & Processing   CCD Imaging & Processing   Solar System Imaging & Processing   Sketching   Astro Imaging/Sketching Contest *Observing* -----   General Observing   Planetary and Solar System Observing   Lunar Observing   Deep Sky Observing   Double Star Observing   Solar   Variable Star Observing and Radio Astronomy*Telescope Specific Forums* -----   Celestron NexStar    NexStar GPS / CPC Telescopes   Questar Forum   Meade ACF/RCX / LX / GPS    Meade ETX*Other* -----   Science of Astronomy & Space exploration   AstroWebsites   Space Rocks*Speciality Forums* -----   AstroArt   Astronomy Software & Computers   Stellar Media   Astro Outreach, Clubs and Star Parties*CN Feedback and Vendor Announcements* -----   Vendor and Group Announcements CN Forums Home

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