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
Trepanning

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Jon Caldwell on December 27, 2001 19:18:47 UTC

You didn't mention the diameter of the disk you were cutting out; this would affect the time it takes. My recent experiences with trepanning have been cutting a 13-1/2" dia. disk from 3/8" thick plate, using 120 grit. This took about two hours, mainly because my motor was under powered. A 2-1/2" dia. hole through a 2-1/4" thick Pyrex mirror took an hour and a half, also with 120 grit. Things to check--cut some teeth or v-shaped notches in the edge of the metal so grit can get in. A notch about every inch along the edge should be enough. If the sheet metal is thin, it might be moving the coarse abrasive out of the way instead of trapping it under the edge of the metal. A thicker sheet metal or finer abrasive might help. 1/16" thick is not too thick; it just makes a wider groove. Apply as much pressure as the motor will take and move the cutter in and out in the groove to let more abrasive/water mix flow in. Good luck.

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 1994-2024 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