A fixed primary and the degrees of freedom of the 2ndry miss an important adjustment. The focal plain of the mirror must be square to the axis of the focuser...
... important adjustment. The focal plain of the mirror must be square to the axis of the focuser so that the focal plain of the eyepiece or camera etc is also...
It is not clear what you mean exactly by "offsetting" - then again, you are far from alone here. As long as you do an optical centering of the secondary as...
John, ... A section (right) through a cone *is* elliptical (a bit counter-intuitive to me as to others, but the old greeks knew it well), so there's no...
Skywatcher is a UK brand too. I believe all is made by syntra in china. The scopes are also rebadged a lot. I don't think it's worth worrying about the loss...
... counter-intuitive to ... problem. If ... centered as ... any light ... center the ... center of ... it away ... into one, ... diagonal ... centered in the ...
I have a full thickness borosilicate 11 1/2 ins blank. (4.3 mirror actually) and am thinking about making a cass out of it (f4/20). I would like to remove...
... Hi John- Do a search for mirror blank curve generator or curve generation and you will get a few hits. At least the ones I'd found used grinding stone...
... You might try searching on "Paul Yoder, Daniel Vukobratovich", or "Lighweight single-arch mirrors". Also, you may want to consider contacting Newport...
... Just a quick reminder that with grinding that much glass off, you'll will want to review safety and material hazards. I'm not an authority on the matter,...
... will ... contains any ... there's no ... I had already come to the conclusion that it's an out side job with much water, polythene and me not in it. Makes...
... From: a.johnw To: atm_free@yahoogroups.com Sent: Thursday, June 05, 2008 8:31 PM Subject: [atm_free] Re: Shaped back mirrors - removing glass and how much...
... how much glass - and ans all ... interested ... Further thoughts such as the one mentioned here might stop me from selling it - but a thin blank might be a...
I read sowhere we can cur plastic or paper whit laser diode from dvd burner I do not have any of these only cd reader for the moement but do someone in the...
You could shape it conical if you don't mind removing all that glass but you better confirm that the blank is free of all strain with crossed polarizes before...
... but you ... polarizes ... came from ... conical ... support ... just ... you run ... small ... much glass ... Thanks Tony. That's something I had worried...
It wasn't a matter of rough and fine grinding but rather flexing of the blank during polishing and figuring. That's what I couldn't get under control. Shaping...
I've always had a bit of a problem thought with complex mirror suspensions. The original now called full thickness blanks were sized to ensure that flexure...
It obvious that supporting thin mirrors has it's difficulties but much depends on how large and how thin. As a practical matter, using a thin mirror in the...
Group, I remember it because it is counter-intuitive. Except that a cylinder may be considered a short section of an infinitely steep cone? The drawings at the...
... A small offset from center of the primary will correct this. It is probably not detectable to the eye in a telescope. For undersized diagonals it may not...
Hi all, I wanted to contact Albert Highe (famous for lightweight scope designs) for some info . . . is he on this list, or does anyone have an email link for...
Have you tryed looking here? http://pw2.netcom.com/~ahighe/home.html ... designs) for some info . . . is he on this list, or does anyone have an email link...
Mel, Maybe I am missing something as I do not see how offsetting the primary or not offsetting it causes pointing error. I guess I'll find out. I want to try...
... Maybe I am missing something as I do not see how offsetting the primary or not offsetting it causes pointing error. I guess I'll find <<< If the primary is...
In discussing adhesives that were coating safe with John Hudek he recommended high quality two-part epoxy but noted that cyancacrylate (super glue) needs water...
Hi Tony, If you don't mind, could you detail what supports you tried that _didn't_ work? It might take a special support of the same glass pitched on to make...
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