Re: ATM 6" Dob: How Easy? How Cheap? How Heavy?

[Gary Seronik <gseronik@direct.ca>]

At 03:08 PM 7/21/1998 +0000, you wrote:
>
>OK, so I'd like a telescope. I think a 6" Newt would be very nice and 
>a slick Dobsonian mount should work well enough.

A good choice, although many will tell you that an 8" isn't much more work.
 Are you planning on making your own mirror?

>
>Recently, I came across a couple of interesting Web sites. University 
>Optics seems to sell everything you need to build a Newtonian OTA

The more you build, and the less you buy, the less expensive your scope
will be and probably the happier you'll feel about it.


>FWIW, I'm looking at the mount from the 
>sidewalk plan but would prefer more of a "high-tech" focuser and 
>secondary mirror mount than their do-it-yourself versions - not that 
>there's anything wrong with that ;-)

For focusers and spiders, check out Gary Wolanski's Web page:
http://www3.bc.sympatico.ca/gwolanski/

In my opinion, Gary makes the best focuser and spiders out there.

>
>For a 6" mirror in an 8" x 48" tube, is all that 3/4" plywood really 
>necessary? I checked Home Depot last week and a 4' by 8' sheet of 
>3/4" birch ply cost 50 bucks and weighs more than my sofa.

I can't imagine why you would need a full sheet of plywood!  You should be
able to get away with considerably less than half that.  For good Dobsonian
plans, I'd spend my first $25 on the excellent "Build Your Own Telescope"
by Richard Berry.  It's loaded with good information and tips.  It's
available from Sky Publishing and elsewhere.

>
>What are the "hidden" difficult steps in building a basic, ugly 
>Dobsonian mount like in the sidewalk 'scope plans? 

If you'll forgive the self-promotion here, I'd suggest picking up the
August Sky&Telescope for the article "Teaching an Old Dob New Tricks."  The
not so obvious elements are discussed there.

>
>Finally, here's how I'm evaluating the financial feasibility of the 
>whole thing. 

Don't forget a couple of eyepieces and a decent barlow lens.  You should
also expect to spend some money on a few books too.

Hope this helps.  Regards,
Gary Seronik