Re: ATM [Fwd: Dobsonian Assistance]

[astrojoe@erols.com]

> MR CHRIS J KLINE wrote:
> 
> > Hello, I am constructing a 10" truss within the month (school has
> > delayed it 2 months!) but I have a few questions:
> >
> > -Is a single ring for the upper assembly adequite for high power work
> > with a 2" focuser?  I mean, is hanging the focuser off the ring ok?

Yes, just use a single thickness of 3/4" birch ply with 11 1/2" id and a
13 1/2" od.

> >
> > -I have a novak mirror cell now, can I use the top part of it (not
> > the tube connector section) and connect it to some steel rungs, like
> > a tailgate?


Yes, I would remove the back piece "Y" and replace it with another piece
of 3/4" birch ply and hinge the ply it so that it drops the mirror down
like a tailgate for servicing/cleaning. Use a drawlatch to hold it
closed.


> >
> > -How do I center the mirror cell with the mirror in it perfectly?
> > I've heard just the slightest error will ruin the scope.
> >

Just use a tape measure. It's kind of critical; but getting the center
good to 1/16" is enough.



> > PS: Is using 1/2" baltic birch and 3/4" poles good for the general
> > construction, keeping in mind I'm only 15 and 110lbs.
> 


Use a single thickness of 3/4" birch ply throughout. 1/2" is too thin
and the 3/4" poles are fine. Birch ply is fine to use if it's cheaper
than the baltic birch. It is available at HOme Depot or any lumber yard.
You can buy a half sheet at Home Depot which is all you should need for
this project. Cost is about $ 22.00 for 4 by 4 sheet.

Joe Castoro