Succeeded in filling the pop. Everything was very cold and so mixing by hand was difficult. The top (to become bottom) is not level. It rises above the edges...
13872
Dnepr
smolensk1
May 1, 2009 9:15 am
Hello, Just joined the group tonight and glad to be here. I was wondering if there are any here who have test information on the 12 and 16 inch GSO mirrors?...
13873
a
ak6666666
May 1, 2009 9:20 am
It flow was like cone ice cream, not thick milk. ... From: a To: atm_free@yahoogroups.com Sent: Friday, May 01, 2009 2:59 . Subject: [atm_free] pop success ...
13874
brock.family
debrock2
May 1, 2009 11:08 am
Hi Steve, I haven't got any test info but a friend of mine bought a 16" GSO mirror and it performs very well indeed. Judging from the star test I would say...
13875
a
ak6666666
May 1, 2009 12:44 pm
Welcome to the group Steve. Ali ... From: Dnepr To: atm_free@yahoogroups.com Sent: Friday, May 01, 2009 10:44 a Subject: [atm_free] Looking for mirror quality...
13876
a
ak6666666
May 1, 2009 12:44 pm
Welcome to the group Steve. Ali ... From: Dnepr To: atm_free@yahoogroups.com Sent: Friday, May 01, 2009 10:44 a Subject: [atm_free] Looking for mirror quality...
13877
Mark Holm
holmmd17
May 1, 2009 10:42 pm
That is about right. Some atm's recommend a more fluid consistancy, but the products are designed to be thick. You can quickly flatten the back by grinding it...
13878
Robert
robt2112
May 2, 2009 2:25 am
I have had one 12 inch GSO on the bench that I tested. Overall the surface error was figured to 1/8 wave, but the surface was rough. The owner of the mirror...
13879
Steve
smolensk1
May 2, 2009 2:55 am
Robert/ et al, I got a reply to an inquiry I sent to GSO about the quality of their mirrors. Below is the text of what they sent me. He attached 2 photos of...
13880
Steve
smolensk1
May 2, 2009 2:58 am
Also, I made an error in naming one of the scopes below - it is Astro-Tech, not AstroCat. ... -- "Where the people fear the government, you have tyranny; where...
13881
Tony Gondola
sailguy28
May 2, 2009 3:00 am
1/2 wave isn't acceptable, even 1/4 isn't anything to get excited about. Also they don't say if it's surface or wavefront error, it makes a difference. Tony ...
13882
a
ak6666666
May 2, 2009 3:16 am
Is surface error a bigger bad news than wavefront error? ... From: Tony Gondola To: atm_free@yahoogroups.com Sent: Saturday, May 02, 2009 10:00 a Subject: Re:...
13883
Mark Whitaker
tnut55
May 2, 2009 4:15 am
For a mirror, a surface defect is doubled in the wavefront. So a 1/4 wave surface error would correspond to a 1/2 wave wavefront error. There are many...
13884
Mark Whitaker
tnut55
May 2, 2009 4:57 am
The ads for the Astro-Tech RC's are inconsistent. I don't know whether that's a distributor oversight or not. I have seen the claim of "1/12 wave or better...
13885
Jan van Gastel
janvangastel
May 2, 2009 5:24 am
Ali, If you want to know what the quality figures mean, study http://www.bbastrodesigns.com/ratemirrors.html Jan ...
13886
Dale Eason
atmpob
May 2, 2009 6:33 am
See files dale eason \ hubble12.5.jpg This is my interferometer analysis of a Hubble 12.5 mirror. A real foucault image is on the right and the surface error...
13887
paulp
paul_p_2002
May 3, 2009 12:29 am
Hi, nice to see a group that is active and not totally spam. my question is how heavy of a spring should I use on a 8" mirror cell? wire spring or standard...
13888
a
ak6666666
May 3, 2009 11:54 am
While pop base is drying out, I restarted the six inch project. After cordal I went to coc but fl increased a lot so back to cordal for a while. Also, for 10...
13889
Greg
gregfurtman
May 3, 2009 12:13 pm
Just about any hardware store will have a selection of different weight & length springs. That's where I get mine for various projects....
13890
a
ak6666666
May 3, 2009 2:20 pm
A large bevel has left the outer 3mm useless. Outer 1 inch of mirror and tool are in contact, not the central 4 inches. How to spread the contact region? ...
13891
Mark Whitaker
tnut55
May 3, 2009 3:19 pm
Here's what you are supposed to do: Grind (MOT) using the chordal stroke until you have reached the desired sagitta for your focal ratio goal. Do not worry...
13892
a k
ak6666666
May 3, 2009 3:46 pm
Thanks a lot Mark. My 45 degree bevel has eaten up 3 mm of radius. Ali ... From: Mark Whitaker To: atm_free@yahoogroups.com Sent: Sunday, May 03, 2009 9:19 . ...
13893
Mark Whitaker
tnut55
May 3, 2009 4:03 pm
Good luck, Ali. What are you using for a tool on the 6" mirror? Mark ________________________________ From: a k <ak666666@...> To:...
13894
a k
ak6666666
May 3, 2009 5:51 pm
11:48 pm COC 1/3 continued. Central 4 inches still not in contact yet. Central pit has spread out. Contact still in one inch ring along the edges....
13895
a k
ak6666666
May 3, 2009 5:51 pm
Thanks Mark. My mirror is 15mm thick and the tool is 8mm thick disk of plate glass. ... From: Mark Whitaker To: atm_free@yahoogroups.com Sent: Sunday, May 03,...
13896
Steve
smolensk1
May 4, 2009 2:14 am
Well, we tested my Hubble-Optics 14" mirror yesterday. I was pleasantly surprised to the max! We do not have an interferometer, but our club has a very nice...
13897
Mark Cowan
toolontop
May 4, 2009 7:55 am
Well, two points (assuming that's 1" thick plate f/5), or two points (if it's a 2" sandwich f/5 at effective 1.2" thickness): 5 zones isn't optimal for a 14"...
13898
gyaneshwar_singh1999
gyaneshwar_s...
May 4, 2009 8:09 am
Dear Sirs, I am new to this group, pl, somebody let me know to assemble a reseaonably good telescope. Wg cdr G Singh(Retd)...
13899
gyaneshwar_singh1999
gyaneshwar_s...
May 4, 2009 8:10 am
Dear Sirs, I am new to this group, pl, somebody let me know to assemble a reseaonably good telescope. Wg cdr G Singh(Retd)...
13900
Steve
smolensk1
May 4, 2009 12:49 pm
Mark, Yes, you are totally correct about the 7 zones. It was an oversight, and I had driven 2 hours one way to get there and had a time definite to be home....
