131112

131112 Telescope Workshop notes 730-9p Tuesday evening, Nov 12, 2013
Attendees:  EdK, TomT, TomW, JerryW, ChrisU, DmitriiZ
-JerryW talking w/ EdK on big mounts for his 12.5inch; plywood split ring equatorial mount picture is on stellafane site.














EdK brought in his 12.5” for retesting as he worked 3hrs of polishing at home in the past week; TomW setup the Ronchi test.  Inside R still showing a turned down edge and flat center.  TomW and JerryW reviewing proper chordal stroke and butterfly stroke with EdK practicing.  JerryW reviewed the article that discussed using different hand pressure on the strokes, but he said that was a very advanced method to correct a turned down edge. http://www.loptics.com/ATM/mirror_making/oblate/oblate.html


















-Dmitrii just starting with his new pitched tool that TomW made a couple of weeks ago.  Little pieces of new pitch coming off during the initial use, but diminished after a few polishing starts.
-ChrisU brought in the finished “flaming tomato” dobsonian assembly, excellent work.  Wants to know how to properly collimate.  Jerry says to make sure diagonal mirror is in the center and the focuser is very perpendicular to the tube.

Using the diagonal mirror longer length, place marks on the back of the secondary holder to correlate with center of the diagonal mirror.  Also center the spider hole with the center circle of the mirror using the mirror cell adjusters.  Laser collimator is last step after mechanically aligning and squaring the components.

See more images / videos here:   Flickr 131112 Tele Work