From: "Dwight K. Elvey" 
To: atm{at}shore.net
Reply-To: "Dwight K. Elvey" 


>From: Arthur 
>
>Hello fellow astro engineer's,
>
>I mistakenly messed with the focal length of all my optics, and made the
>tri-point, screw in mirror cell holes 1/2 inch oblong Inaddition, I moved
>the spider down with the new holes centered between the origian two.Stupid,
>yes I know, but I did it. Now I need help determining how to fix this mess.
>My questions are:
>1.  how do I fill in the holes (with what substance), and redrill the
>original holes,or
>2. fill those holes and re drill new holes for the mirror cell and spider a
>half inch or so to the left or right; but if I do this, what will be the out
>come in relation to the focuser hole?

Hi
 There is no requirement that the mirror cell holes be aligned with
the focuser. The spider mounting holes also have no special alignment
either( most spiders allow the secondary to rotate on axis ). There are
some wood putties that work well as filler but I recommend that you drill
new holes slightly away from the holes you have. Do it a step at a time.
First mount the spider and get it right. Next slide the primary into the
tube. Make sure that the primaries screw adjustment are at mid range. With
the help of a friend, adjust the primary to focus an image of something far
off( Moon works very well ). Mark where the cell should be and then drill
holes.
 Take your time and worry about the old holes later.
Dwight

>
>or, if you have another suggestion, please let me know. Replacing the tube
>is out of the question.....
>
>Arthur
>
>
>

--- BBBS/NT v4.01 Flag-4