On Tuesday, April 21, 1998 2:53 AM, DM Roady wrote:
> Hi All,
>
> It looks like I may have to adjust the fork and tube alignment to
> achieve better orthogonality. The last time I calibrated my dec
> circles, I noticed that I have a large? (1/6th of 8x50 field)error in
> orthogonality. The calibration in declination went well. I have read
> the methods described in Stuart's MAPUG Archive, yet these methods don't
> seem to go into detail about how you actually fine tune the parallelism
> of the forks or the alignment of the tube using the 4-40 set screws. My
> specific questions are:
> 1. Is this a common thing that the more experienced mapugger's have
> routinely dealt with on their scopes? Either as a primary problem or
> related to fixing some other problem. There's not much reference to
> this in the archives.
> 2. Has anyone tried fine tuning the tube bracket set screws while
> observing the alignment star? Or is this procedure best done on the
> work bench?
> 3. If I loosen the tube bracket screws, what is the danger of the tube
> falling?
> 4. Is there anything inside the tube that I can mess up just by
> loosening the tube bracket screws?
> 5. Adjusting the fork arms would seem to be the most imprecise part of
> the whole operation. How does one accurately do this while fighting the
> weight of the tube?
> 6. My goal is for the star to remain inside the outer ring of my 9mm
> IREP (about 80".) Is this a realistic goal assuming a very stable
> mount?
>
> Any thoughts or methods would be greatly appreciated, just trying to be
> careful lest I screw something up!
>
> Dave Roady
>
>

See Doc G's Info Page for details to accomplish what you describe
with details and illustrations under Mechanical Concerns, LX-200
Mechanical Fixes, Rebuilding the Declination System:
http://www.mailbag.com/users/ragreiner/

The adjustments to the mount outlined would also apply to the LX-50
which uses the same physical mount and forks as the LX-200.


--
Michael Hart
Husen Observatory

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