Re: [ATM] Hello list, some basic question for a new Dobsonian builder

[Mike Lockwood <melockwo@uiuc.edu>]

Mike,

Mike Shuken wrote:
> e-scopes has a 10" f/5 with a 1/10 wave and they include a secondary for 
> $399.00 http://e-scopes.cc/

Just remember, you get what you pay for.  This mirror will probably be 
good, but not perfect.  If you ever decide to grind a mirror, you can 
always learn to test on a purchased, coated mirror.  You can also have 
it refigured if you demand perfection later on.

> For the focuser, I was going to pick up an Orion $39 job that is 2" with 
> a 1 1/4" adaptor - seems to be a nice piece for the price.

I used this focuser on a small scope.  It works OK, but at F/5 you may 
have a little trouble doing critical focusing.  I still recommend a 
well-made Crayford.  My favorite mid-priced model is MoonLite, but 
they're not cheap.  This is one item where spending $$ really makes 
observing more enjoyable, IMO.

> I decided to build my own spider, but use masonite instead of ceder 
> shingles.  We'll see how it goes, I might end up buying a commercial 
> one, but I wanted to try my hand at it first...

You want to make the vanes as thin as possible.  Thin metal or wire is 
used by many of us.  Thinner vanes cause less diffraction.

> Can't wait to get started, http://e-scopes.cc/ says they have the 10" 
> f/5 in stock - if you think this is a reasonable mirror and price, I'm 
> ready to order and get started building!

Excellent.  Just make sure you have fun with the building process.

	Mike Lockwood

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