Re: ATM which one first

[Ari <Ari@birmingham-us.crosswinds.net>]

Tim wrote:
> 1. I have looked at different kinds of focuser, Ilike the helical the
> best. Rack and pinion are fine but just doesn't appeal to me. Is there
> any draw backs of this type? Is there a general "best"?

I don't think so...Crayfords are susposed to be really nice. As I
understand it, the problem with helicals is that they take to many
cranks to focus very far.

> 2. Upon construction, Which one is wise to make first, The mirrors or
> the base and tube? I want to make the base and all of the other stuff
> before the mirrors. Any comments?

It doesn't really matter...the only problem I can forsee is if the focal
length of your mirror doesn't exactly match your tube, you are going to
have some holes in the wrong place.

> 3. Whats easier (Time wise) to make 8" f/8 or 8" f/6?

>From what I've heard, the f/8 should be easier to make.

> 4. A parabolic curve is sunk in.(can't really explain it). Whats a
> sphere?(spherical)?  What is the ultimante goal for making a mirror?

"sunk in" means concave? Spherical is also concave. The atmpage explains
this fairly well.
http://www.atmpage.com/design/conic.html

> 5. Who funds this mailing list ?

Mel Bartels runs it, and as far as I know, it resides on his computer,
or his ISP account...

Good luck,
Ari Friedman
        There's light at the end of the Sonotube.