http://tech.groups.yahoo.com/group/Astrograph/ Astrographs, Rosin Project and others Wed, 23 Dec 2009 14:41:12 GMT Thierry Fabre Yahoo http://tech.groups.yahoo.com/group/Astrograph/message/396 http://tech.groups.yahoo.com/group/Astrograph/message/396 hi, folks ;) i remember an ATM sled focuser, maybe a good way : http://www.binodob.de/bino_eng.html saw a 3D drawing, so maybe possible to ask for sled focuser Wed, 23 Dec 2009 04:09:32 GMT MorrisB http://tech.groups.yahoo.com/group/Astrograph/message/395 http://tech.groups.yahoo.com/group/Astrograph/message/395 Arthur, i shall shortly be approaching the corrector lens cell design point and I wondered what you decided to do. Anyone's ideas are welcomed at this point :) Fri, 23 Oct 2009 15:05:27 GMT a http://tech.groups.yahoo.com/group/Astrograph/message/394 http://tech.groups.yahoo.com/group/Astrograph/message/394 Greetings all, I thought I would provide an update on my progress with a 10" f/4.5 Rosin using COTS lenses, based on Ed's design (see the 4.1 in Ed's files). I Wed, 12 Aug 2009 13:09:50 GMT Ed Jones http://tech.groups.yahoo.com/group/Astrograph/message/393 http://tech.groups.yahoo.com/group/Astrograph/message/393 Arthur, You might ask OptoSigma and Melles Griot if they can coat just one side, it might even be cheaper. If they can't then you'll need to remove the coating Wed, 12 Aug 2009 03:52:46 GMT arthur suits http://tech.groups.yahoo.com/group/Astrograph/message/392 http://tech.groups.yahoo.com/group/Astrograph/message/392 Ed, I like this very much. I did manage to enter it into Oslo, and the good news for me is that it seems I can use essentially the same settings and lenses Mon, 10 Aug 2009 13:57:16 GMT Ed Jones http://tech.groups.yahoo.com/group/Astrograph/message/391 http://tech.groups.yahoo.com/group/Astrograph/message/391 Arthur, Yes there is some interference. The sags aren't listed in the lens catalogs so I decided to just grind down each lens flat until the airspace is right, Mon, 10 Aug 2009 11:08:12 GMT arthur suits http://tech.groups.yahoo.com/group/Astrograph/message/390 http://tech.groups.yahoo.com/group/Astrograph/message/390 This sounds great. But in the picture it almost looks like there is some interference between the lenses, Is that true? Two more questions: where are the Sun, 09 Aug 2009 16:58:22 GMT Ed Jones http://tech.groups.yahoo.com/group/Astrograph/message/389 http://tech.groups.yahoo.com/group/Astrograph/message/389 Forget the 12 inch astrograph, I uploaded a better one, 10 inch f.4/1, you just buy the lenses and don't need a spacer. Ed Thu, 30 Jul 2009 22:11:15 GMT Ed Jones http://tech.groups.yahoo.com/group/Astrograph/message/388 http://tech.groups.yahoo.com/group/Astrograph/message/388 I'm having fun designing these, don't know how useful they are though. Anyway I uploaded a 12.5 inch f/4.3 using a 12 .5 inch f/4 mirror refigured to a Thu, 30 Jul 2009 16:06:56 GMT Ed Jones http://tech.groups.yahoo.com/group/Astrograph/message/387 http://tech.groups.yahoo.com/group/Astrograph/message/387 Hi Mike! 3 of the 4 lenses are from OptoSigma and one is from Newport Optics, the catalog numbers are listed. The signs on the 2 curve are intentional, I Thu, 30 Jul 2009 02:06:35 GMT Mike http://tech.groups.yahoo.com/group/Astrograph/message/386 http://tech.groups.yahoo.com/group/Astrograph/message/386 Great application of commercial optics, and nice sharp images over the 0.4-0.85um band and 0.7" field diameter. Which companies are the lenses from? Note: Wed, 29 Jul 2009 19:45:49 GMT Ed Jones http://tech.groups.yahoo.com/group/Astrograph/message/385 http://tech.groups.yahoo.com/group/Astrograph/message/385 I uploaded another hyperbolic astrographic design that uses two meniscus corrector lenses. To make it easy to make I split each lens into a plano convex and Tue, 21 Jul 2009 17:19:00 GMT Frank Tomaszewski http://tech.groups.yahoo.com/group/Astrograph/message/384 http://tech.groups.yahoo.com/group/Astrograph/message/384 Good news!!! Protostar shipped my spider today. It should be here by the end of the week. I now have everything I need EXCEPT a way to attach the primary Thu, 11 Jun 2009 21:18:59 GMT Morris Bagnall http://tech.groups.yahoo.com/group/Astrograph/message/383 http://tech.groups.yahoo.com/group/Astrograph/message/383 Thanks Frank. I may hold off till yours arrives and you can let us know what you think. Any idea how long till you get it? Did you get a secondary heater built Thu, 11 Jun 2009 14:52:28 GMT Frank Tomaszewski http://tech.groups.yahoo.com/group/Astrograph/message/382 http://tech.groups.yahoo.com/group/Astrograph/message/382 Morris, I just recently ordered my spider from Protostar. I chose to have the vanes straddle the focuser with my offset built in. Frank