140304

140304 Telescope Workshop notes 730-9p Tuesday evening
Attendees:  TomT, JerryW, TimC, DmitriiZ, ChrisU

JerryW brought in motorized JMI focuser, w/o motor controller, to donate to 8” donated mirror telescope TimC is working on.  TimC checking curve to see if it would fit 8” tube.  Tim doing 5 micron polishing this evening.

 Dmitrii brought in 12.5” mirror for evaluation.  He thinks 12 hours of 12.5 micron polishing has been put in since the improper polish was used.  A little scratch in the surface, but laser checking is otherwise fairly consistent across the mirror.  Green higher power laser seems to give a sharp reflection off the surface.  Jerry looking at Jean Texereau polishing chart with a curve of number of pits left as hours are put into polishing.

Some time was spent on inviting folks to an Apple icloud area to post photos, then looking at a 3D optical illusion of Saturn stored there.

ChrisU having trouble getting in touch with Newport Glass for cerium oxide.  Jerry says China drove people out of business making the stuff, so now hard to get. CR Lawrence, National Abrasives, and Willman Bell may be other sources.