To: atm{at}shore.net
From: Matt Brown 
Reply-To: Matt Brown 


I made one, and it performs quite well.  You can see my link at
  http://host67.everstrive.com/~mlbrown/ASTRONOMY/sixinch.html

It took twice as long to make it than making the mirror, much of it because
I didn't have access to a decent workshop nor woodworking equipment.  I
would highly recommend getting a router with a circle cutting setup,
because this design has a lot of circles in it. I had a hard time making
the rings holding the tubes -- they are somewhat fragile.  The one aspect
of the design I'd change is the way these attach:  I plan on redoing them
using hinges on one side and luggage clamps on the other.

It is also very heavy, about 60 lbs without the optical tube assembly.  It
is more stable than my friends 10" dob mount, but his is much more
portable.

I plan on motorizing it someday, but I think I'll need to remake the RA
bearing to make it more concentric, and for that, I'll need a lathe I
think.  And, I need to make the RA bolt fit tighter into the rotational
disk so the axis doesn't wander too much.  I think it is doable, but a nice
big ball bearing set would have worked better.

There are a few dimensions missing from the design, though nothing critical
-- things like the dimensions of the central post, or the lateral spacing
of the bolts that mount the RA axis to the post (you need to space them far
enough apart to clear the post), so review the design carefully to fill in
these numbers before cutting wood.

If this were a beginner, I would direct them more toward the dob design --
it took a long time to make this thing, and it might be discouraging for
not a great benefit -- you can follow a star with a dob almost as easily as
the equatorial mount, and this design needs to be well made to make it
motorizable.

=Matt




>A person who is making a 6" mirror in the NCA (Wash. DC) mirror-making
>workshop is planning on following the detailed plans for a 6 inch
>equatorial-mounted Newtonian reflector that are printed in one of the
>chapters of Richard Berry's book, Build Your Own Telescope. (I might have
>the title a bit off.)
>
>Has anybody else out there built one of these things? If so, how did it
>perform?
>
>Guy Brandenburg
>
>
>

--- BBBS/NT v4.00 MP