RE: ATM 20": first light

["Ashish, Balaya (IE10)" <ABalaya@meghadoot.hiso.honeywell.com>]

Congrats Hugues and "Wow" - a 20 incher. Wish I had one!!
   It always makes me happy when a fellow astronomer also makes his own
'scope. Believe me, I save all mails like these in a folder called
"Experiences" and it gives me great joy to read them in my spare time.

Hope you enjoy your instrument for ages to come.

clear skies,
Balaya

> -----Original Message-----
> From: Hugues_Laroche@ses-astra.com [SMTP:Hugues_Laroche@ses-astra.com]
> Sent: Monday, July 26, 1999 6:38 PM
> To:   atm@shore.net
> Subject:      ATM 20": first light
> 
> 
> 
> Yahoo!
> 
> Yesterday evening I completed my 20", whatever it means... I am
> probably particularly thick and slow: what an amount of time
> the building of such a scope requires! Also, to all
> big-dob-builders-to-be:
> be warned that an assembled scope is bigger than what you would
> expect when handling the mirror alone! That does not say "dont do
> it", just be prepared for a certain form of surprise.
> 
> Sooo. It is a 500mm diameter (so not exactly 20") f/4.2; it is not
> correctly
> collimated so far, so I guess that's why M13 was a bit deceiving: the
> stars
> hardly resolved. The effect of bad alignment was quite visible on brighter
> stars. But I could see M57 much more intense than with the 10", it
> was marvelous! Not speaking about the moon, which spoiled more than
> half of the sky.
> 
> A nuisance: the scope is considerably bottom-heavy. OK, it is easier
> to cure than the inverse. Still need to baffle the sec. cage and put
> a shroud around the truss.
> 
> And, finally, the truss should still be shortened a bit: only a 30mm
> eyepiece pushed to the max. towards the secondary could focus :-(
> Once corrected, it will agravate my bottom-heavy problem BTW
> (normal, if one take Murphy's law into account).
> 
> It is such a marvelous moment when looking for first time through an
> instrument you have done with your hands (well, with some tools too ;-)!
> It has been said several time, and although if I experienced it already
> myself, it remains nearly magical. Sorry to take a bit of bandwidth with
> that.
> 
> To make it, I am in debt of help from Mel for figuring,
> Richard Schwartz for an unequal loads cell computation,... and many many
> of
> you, directly or indirectly. I have still not motorised it yet (sorry
> Andy!).
> Thanks to all (and Mr Texereau!)... just wished I had know this list
> earlier (I
> would
> have ordered a blank of better quality, in particular)!
> 
> Still need tracking, a CCD and a web site and I hopefully can supply
> pictures
> too
> (not tomorrow, seemingly)
> 
> A bit euphoric...
> 
> Hugues
>