[Atmob-club] observatory design question

[John Sheff]

I am agnostic on the roll-off vs. dome issue, but just to add to what John
Small said about the roofdeck at Harvard, our 9" refractor is mounted on a
concrete pier and is very stable, but there have been numerous times when
we've had a half-dozen or so scopes set up on portable bases or tripods, and
yes, foot traffic vibration is DEFINITELY a problem. Even when you go out of
your way and be extra careful to position the tripod legs on masonry tiles
that viewers aren't likely to step on, nearby foot traffic vibration is
transmitted and is readily apparent when you're viewing your target - more
so, of course, at higher magnifications. For casual viewing, it's just a
nuisance, but for serious work, it might be a limitation you'd rather not
want to live with if you have a choice.

- John Sheff


-----Original Message-----
From: atmob-club-bounces at atmob.org [mailto:atmob-club-bounces at atmob.org] On
Behalf Of Small, John
Sent: Tuesday, January 15, 2008 12:56 PM
To: pbealo at comcast.net; George Roberts; atmob-club at atmob.org
Subject: Re: [Atmob-club] observatory design question

I am in agreement with Peter KISS and stay with the rolloff.  TO make
one small change to the building process of a new school (or any public
building) will cost far more than the roll off in the field. The
building committee, architect and contractor's will need change orders,
and they will charge through the nose for them.  You would need fences
and a walkable surface on the roof if the public comes up, snow removal,
access and ADA Acccessable Acess. Harvard is a private institution so
they can sneek around the ADA access

The fact that it may not cost much in materials is mooted by the
political process that you will need to go through, think of all those
countless nights at meetings that you could be observing instead.   

Harvard Public affairs has issues too with the roof scope.  Many nights
we have had to close observing due to snow removal problems and ice 

Just my 2 cents worth
John Small