Re: [ATM] History of moving mirrors for Schmidt Cassegrains.

[Ken Lowther <hermit@outofoptions.org>]

I saw a an old Celestron that had 3 lead screws that moved so that the primary
didn't 'flop' around.

Ken

Quoting Andy Saulietis <iss@pvtnetworks.net>:

> Re moving mirror focusing:
>
>> Designed for Celestron as a way to get a very large focal range.  The basic
>> design was then copied by Bausch and Lomb and then Meade (apparently no
>> patent on the method?) and is the way that the SCTs focus as a result.
>> The basic design does have the bad flaw of not being able to hold the
>> primary in collimation as focus changes but the spherical primary does help
>> a lot in hiding the problem.
>
> Questar also uses this method, their OTA is Maksutov. Don't
> know if they predate Celestron, but the Questar one doesn't
> go out of collimation..much better designed/made. Lots
> more $ also..
>
>
> Andy Saulietis
> ISS Enterprises
> 10 Milky Way
> Mayhill NM 88339
>
>
> World's first astronomy land development:
>
> http://www.pvtnetworks.net/~iss/starend1.htm
>
> 11 of 17 lots sold to astronomers as of 4/08/04
>
> 505-687-3067 voice/fax, call voice or e-mail to set up
> e-mail: iss@pvtnetworks.net
>
> Also available: Custom large telescopes/mounts,
> 25 & 50 mm manual filter wheels, HDPE worm gears & clutches,
> HDPE friction drives, CCD sliders & turrets, custom
> telescope parts machining.
>
>
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/



Hermit, holed up in Youngstown, Ohio
_______________________________________________
ATM mailing list http://www.atmlist.net/