http://tech.groups.yahoo.com/group/roddier/ Roddier Test Sat, 21 Nov 2009 17:23:37 GMT Marshall http://tech.groups.yahoo.com/group/roddier/message/698 http://tech.groups.yahoo.com/group/roddier/message/698 ... Dr. Biretta - it's wonderful to hear from you again and know you are still around. We can surmise what's been happening in your world since the Hubble Sat, 21 Nov 2009 03:01:12 GMT zeissnut http://tech.groups.yahoo.com/group/roddier/message/697 http://tech.groups.yahoo.com/group/roddier/message/697 Chris, I made some efforts along the lines of your item (1) some years ago using Aberrator. The primary issue is that Aberrator does not seem to have linear Sat, 21 Nov 2009 02:25:50 GMT zeissnut http://tech.groups.yahoo.com/group/roddier/message/696 http://tech.groups.yahoo.com/group/roddier/message/696 Hi Mick, I'm still here lurking in the shadows. Maybe I'll have more time for it in coming weeks. I don't have any insights yet to the apparent contradictory Fri, 20 Nov 2009 22:28:46 GMT Chris http://tech.groups.yahoo.com/group/roddier/message/695 http://tech.groups.yahoo.com/group/roddier/message/695 Yes, still here, thinking about, but no results on the following: 1)Testing Roddier with computer generated data, an extended Aberrator of some kind. Still Tue, 17 Nov 2009 19:08:29 GMT Marshall http://tech.groups.yahoo.com/group/roddier/message/694 http://tech.groups.yahoo.com/group/roddier/message/694 ... Bron - the 0.001 inch runout I measured on my focuser (JMI NGF-DX2) was reasonably linear and progressive, meaning that the sideways motion over an 8 mm Tue, 17 Nov 2009 17:48:26 GMT bron gervais http://tech.groups.yahoo.com/group/roddier/message/693 http://tech.groups.yahoo.com/group/roddier/message/693 If my rusty trigonometry is correct, that focuser runout gives an error in spot location on the primary of 0.83mm at 1524mm (60"). I thought that errors of Tue, 17 Nov 2009 14:25:07 GMT Jerry http://tech.groups.yahoo.com/group/roddier/message/692 http://tech.groups.yahoo.com/group/roddier/message/692 I read all of the posts. I think the roddier technique is very interesting but unfortunately I have not tried it yet myself so I have little to contribute. Tue, 17 Nov 2009 00:06:07 GMT bron gervais http://tech.groups.yahoo.com/group/roddier/message/691 http://tech.groups.yahoo.com/group/roddier/message/691 Mick, It's hardly a project in my eyes, compared to your other efforts ;-) A cheap laser, a cheap Barlow, and a spare filter turned into a target. The BL for Mon, 16 Nov 2009 23:43:59 GMT Marshall http://tech.groups.yahoo.com/group/roddier/message/690 http://tech.groups.yahoo.com/group/roddier/message/690 ... Bron - thanks much for the kind words and encouragement. I joined this group for exactly the same reason as you, and am still hopeful of that endeavor. Mon, 16 Nov 2009 23:29:29 GMT Marshall http://tech.groups.yahoo.com/group/roddier/message/689 http://tech.groups.yahoo.com/group/roddier/message/689 ... Bron - thanks for the suggestions. As explained in the documents mentioned in my last post, I carefully checked the motion of the focuser drawtube using Mon, 16 Nov 2009 23:19:59 GMT Marshall http://tech.groups.yahoo.com/group/roddier/message/688 http://tech.groups.yahoo.com/group/roddier/message/688 ... Sander - good to see you here and glad you're at least lurking; if you have any thoughts/opinions on some of the stuff in my latter posts I would be very Mon, 16 Nov 2009 22:53:46 GMT bron gervais http://tech.groups.yahoo.com/group/roddier/message/687 http://tech.groups.yahoo.com/group/roddier/message/687 Mick, I have been following and find this all very interesting. However, I'm convinced this is over my head and my needs at this juncture in my amateur Mon, 16 Nov 2009 22:51:44 GMT bron gervais http://tech.groups.yahoo.com/group/roddier/message/686 http://tech.groups.yahoo.com/group/roddier/message/686 Mick, Is it possible that the way you judge the holding of collimation might be improved? Have you removed focuser slop and laser internal misalignment for Mon, 16 Nov 2009 22:22:02 GMT Sander Pool http://tech.groups.yahoo.com/group/roddier/message/685 http://tech.groups.yahoo.com/group/roddier/message/685 Hi Mick, I'm here but just lurking. Sander Mon, 16 Nov 2009 21:51:04 GMT Marshall http://tech.groups.yahoo.com/group/roddier/message/684 http://tech.groups.yahoo.com/group/roddier/message/684 Group - with the exception of a single item on 1 Sept 09, I am the only person to post anything to this forum since 12 June 09, a span of slightly over 5