130910

130910 Telescope Workshop notes
Attendees:  EdK, TomT, TimC, TomW, Martin Meza, ChrisU

TimC-showed us the Kindle book “Understanding Foucault” by David Harbour [ http://www.amazon.com/Understanding-Foucault-David-A-Harbour/dp/1934916013 ] on his Samsung tablet.

TomW- on EdK's 1968 pyrex 12.5” f/5 mirror:  polishing 60min the raised center with a 6” and center only motion.  TomW also set up the Ronchi tester, with the grating, to check the mirror progress.  Foucault test was done also. Center looking better, but a lot of heat was coming from the mirror due to the polishing.

TimC-continued his work on donated 8” mirror grinding to f/5 with 120.  TimC let TomT practice the grinding cycle/motions (1/3 over centers) with the mirror.  Since proper depth has been reached, the mirror glass blank and the tool were switched bottom/top positions about every 3 grinding cycles around.  At the end, TimC showed us the cleaned off surface of the mirror glass showing a more evenly ground surface.

Martin brought in his 8” Dobsonian with a dovetail mount that he had purchased from Mike Farris.  The unit has a mirror that was aluminized in San Carlos, May 2008.  The focuser was donated to Mike by JerryW.  He will be offering this unit up to ChristopherU for $175 or so as CU has been looking for a finished 8” mirror.  Chris accepted the deal, and TomW bought the dovetail assembly from Martin.
More Photos/Vids here: http://www.flickr.com/photos/27241501@N03/sets/72157635600207075/with/9792371316/