Oh great, powerful, all knowing list. I bring my humble self before you
seeking light and guidence, as it is known by all that enlightenment can be
found only through following your teachings…..yadda yadda yadda

Now…that the smoozing is over….

I have had my 10” f10 LX-200 for about three weeks now, and it never did
GOTO very accurately out of the box. I have had the chance to use a couple
other LX-200 that just put every target smack dab in the middle of the
eyepiece, so I am convinced they all should be able to.

To that end I started tinkering…errr…improving…this thing. About this same
time my secretary sent me the “You might be an Engineer” list. I like
number 15, you might be an engineer if you see a good design and have to
change it, and number 14, if you look forward to Christmas so you can change
how the kids toys go together.

I did the light projection onto the RA bearing alignment that is found on
the MAPUG site. This seemed to improve things quite a bit, but still only
put most objects in the FOV, not in the middle of the eyepiece. Then I
found the alignment that uses a laser reflected off the corrector plate to
check the orthoganality. This made since and seemed like a good idea, and
besides, anything using a laser is sexy, isn’t it? . I adjusted that thing
down to a nats…butt…I mean the circle transcribed by the laser reflection at
30 feet was smaller than the diameter of the laser wavefront. Well, this
improved the GOTO even more, but it would still not be good enough to put a
target on a CCD, and that is my goal.

So I started thinking along the following lines. I need to take the whole
of the optics into account, as the corrector plate could be off by a small
amount in relationship to the axis of the OTA. If I put my LX-200 on my
wedge, and then set the Dec to 90, and then align the wedge so Polaris is in
the center of the eyepiece, I should be able to spin the mount in RA and
Polaris should stay centered. If the star produced an ellipse or a circle
this would be an indication that the scope was not orthoganal. Naturally I
should be able to remove any movement in one plane with the Dec axis, but
the other would have to be removed by adjusting the OTA alignment screws at
each side of the tube. Anyone see anything wrong with this thought process?
Am I missing something?

The reason I ask is, I tried this last night, and I never could get the star
to even stay within the FOV for one rotation. No adjustment would make it
better, only worse. This was using a 40mm EP with a FOV of about one full
degree. What am I missing?


Darrell
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