Re: [ATM] Ultra-Thin EdgeSupportIdea-RE:[atm_free]ULTRA-THIN30"mirror from Hong Kong

["A. Suijkerbuijk" <a.suykerbuyk@wxs.nl>]

Hi James,

Three of the levers are replaced by bolts, these serve for collimation. The 
bolts are 120 degrees apart. The outer ring of supports is close to the 
edge, and side supports are placed close to the bolts, so there is less 
danger for astigmatism.

Regards,
Adrie

----- Original Message ----- 
From: "James Lerch" <jlerch1@tampabay.rr.com>
To: "ATM" <atm@atmlist.net>
Cc: <atm_free@yahoogroups.com>
Sent: Saturday, January 28, 2006 7:32 PM
Subject: Re: [ATM] Ultra-Thin Edge 
SupportIdea-RE:[atm_free]ULTRA-THIN30"mirror from Hong Kong


> CS> I posted a link to a picture of such a cell but the link was 
> truncated, so
> CS> let's see if this works:  http://tinyurl.com/acww5
> CS> Here is one for a 36": http://tinyurl.com/df6vq
>
> Asides from the fact I still don't see how an astatic support is superior 
> to a
> whiffle tree support, I've always wondered "How do they keep it 
> collimated?"
>
> Astatic = not static = something moves = And / Or combinations of
> friction,stiction, hysteresis, oscillation
>
> If the system is disturbed, what guarantees it will return to its starting
> position?
>
> I gather the idea behind an astatic cell is the weight of the mirror 
> presses on
> a lever.  The lever attempts to pivot around a hinge.  This attempts to 
> move an
> equal mass an opposite direction.  With the hope being that the forces 
> cancel.
> As I see it a whiffle tree does the same thing, but with less parts...
>
> Take Care,
> James Lerch
> http://lerch.no-ip.com/atm (My telescope construction,testing, and coating 
> site)
> http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


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