ATM (no subject)

[Gary Myers <gmyers@CetLink.Net>]

Richard Keppler wrote:
> 
> 
>  Yes, very true, but how do you manage to get it to _exactly_ 45
> degrees.  I have looked mine over and there is no way that I could get
> it aligned to that precision without the use of a laser after
> mechanically centering the spider's diagonal hole over the center of
> the primary, which would also have to be optically perfectly flat.  I
> know it could be done, and I remember reading about it on the ATM list.
>  Possibly it was your description of this very process I now recall.
> 

One rather easy way that I did it was to place the secondary holder on a
flat level surface. Tape a string level flat to the bolt end - adjust
the tip of the holder back and forth with pieces of paper under the
front or rear to make the level bubble centered. Now you know a
reference point. Now take a combination sq (it has a 45 built in) and
hold it over the mirror right on top of it but not quite touching it -
it can be done easily without threat of touching the mirror. Now it is
apparent which way the mirror is off! Mine was off by quite a bit!!! 

G.