Back to Home

ATM Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | Amateur Telescope Making | Post
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
Grinding

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Robert May on August 9, 2002 18:56:48 UTC

When you're using a iron tool, the ROC of the tool doesn't change very much (it can and does move a little bit but that is a lot slower than the glass does) with one mirror so you really need to have the right ROC in the first place.
Once you go to a tile or glass tool, the ROC will change a lot faster and you do need to keep track of the changes to that ROC. Even at the 25 micron grit size, you can quickly change the ROC by sevral percent in a few wets.
FWIW, I have a pair of 2" end caps for iron pipe that the group's mirror grinders have been using and, after a fair number of different users (several years now) the fat ring around the end of the cap is about 2/3 gone. These caps have been used as ring tools for anything from 6" to 12.5" mirrors. This, I think, tends to indicate how slow the iron will move with grinding over the use on a single mirror - yep, it will move but not very far!

Follow Ups:

    Login to Post
    Additional Information
    Google
     
    Web www.astronomy.net
    DayNightLine
    About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
    Unless otherwise specified, web site content Copyright 1994-2025 John Huggins All Rights Reserved
    Forum posts are Copyright their authors as specified in the heading above the post.
    "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
    are trademarks of John Huggins