Re: ATM Setting Circles.

["David Harbour" <scarab@peakonline.com>]

Joe-

Make your own. Get a quality drafting protractor, and have a photo buff make
a contact print of it in his darkroom on a piece of RC photo paper, cut it
out and laminate onto the material of your choice for the circle.

I made a super accurate large setting circle template for right ascension
(and one for declination) by laying out and bisecting angles with a beam
compass (trammel) starting by subdividing a circle into a hex. When the
angles become too narrow to lay out by further angle subdividing, simply
subdivide by setting the compass's center point on already laid out marks
farther away from the ones that are adjacent each other. For an example of
this kind of declination circle- it is super accurately laid out- look at
one of the pictures on the second page at my site- there is a picture
standing by my big fork mount and the large 21" diameter circle ('C") is
well shown. And I have close-ups of it if you would like to get one or two
as an email attchment. This is really easy to do . I like really big circles
for accuracy and ease of reading. Let me know if I've been of any help and
possibly put some new ideas in your head. Yes, setting circles are still
alive. Old guys like them. I am an old guy, and I like old technology- to me
old technological forms were some of the best art human beings ever
produced. I think on of the components of the word technology" is,
etymologically, derived from the word "art". See my big circle at:
www.greatplainsinstruments.com

Good luck-
Dave

----- Original Message -----
From: "Joe Mayenschein" <mayen1@mwt.net>
To: "ATM!" <atm@shore.net>
Sent: Saturday, August 04, 2001 8:36 AM
Subject: ATM Setting Circles.


>
> Setting Circles,
> Setting Circles? What are those? In this day of digital encoders and all
this GOTO
> stuff, does anyone still have a source of Setting Circles?  I'm looking
for a set
> that is about 3" in diameter. with a little over a 1" shaft size would be
perfect,
> but that I can work around. But the 3" OD is about as large as I can go on
the GEM
> I'm building.  Any one know of a source?
>
> Joe
>
>