131119

131119 Telescope Workshop notes 730-9p Tuesday evening
Attendees:  EdK, TomT, TomW, JerryW, ChrisU, DmitriiZ

EdK brought in his 12.5” mirror for retesting as he worked 3hrs of polishing at home in the past week; TomW will setup the Ronchi test.  Inside R still showing a turned down edge but center spherical zone is expanding.












 Dmitrii polishing his 12.5" and he made a very sensual video of the polishing motion and stroking action.  Of his mirror. Check the link to Flickr photos at the end of this blog for my take.

TimC starting with 320 grit on the donated 8” mirror.  It was a very quiet and smooth grinding action at that grit.  Found a pit showing a shadow inside the glass, in the surface at the end of the grinding with the loupe.
 









ChrisU reviewing the positioning of the secondary on his Dobsonian with TomW.  No one had a collimator to check, but long allen wrenches were needed as well.  TomW finds small plastic thumbscrew covers for socket head screws to eliminate the need for wrenches.  This might be a link:  http://www.mcmaster.com/#thumb-screws/=phclpe


TimC is working on some star hopping charts at home with Photoshop layers involved in his work.