Re: ATM - Where to buy mirror blanks, grit etc.

[Robert Duvall <rduvall@pixworks.com>]

Jay Shroff wrote:
> 2. Would an 8" mirror be okay as a first project or should I go with a
>    6" mirror ? I prefer an 8" as I've a 6" but I would like to hear
>    what's worked best for all the experienced opticians!

I had an old f/10 6" mirror that I refigured to be a faster f/4.8. All
told, it took between 25-30 hrs, depending on how you count every idle
minute. It was a piece of cake. Yes, I had some some nerves making my
first pitch lap, etc. but after it's done, you realize it's not hard. 

If I were to start from scratch, I'd make an 8". The difference in what
you can see between an 8" and a 6" is significant- you've got almost
twice the area collecting photons and better resolution. If you look in
deep sky catalogs, you'll find that there's a real difference in what an
6" and 8" scope can detect, or detect WELL (which is what you want). 

Dozens of first timers have finished 8" mirrors at the Chabot TM
workshop with very little help. I encourage everyone to start with an
8". The mount is hardly any bigger/heavier/or more difficult, the tube
is about the same, and the eyepieces, focuser etc are the same. Thus you
get alot more for your money with an 8". In fact, you can BUY an Orion
6" mirror for less than you can make and aluminize one. That's NOT true
with the 8" or larger.  

As far as larger sizes, say a 10" or 12... Well, I'm now making a 12.5"
and it's a LOT more work than the 6" ever thought of being! Of course
the 'cass hole in the center isn't helping me either. Good thing I enjoy
pushing glass!  I would not recommend bigger than a 10" to start. My 6"
will be used mostly by my kids and their friends once the 12.5's done. 

Long term, I think you'll be much happer with the larger 8" scope. Just
the thoughts of a relatively new mirror maker.