From: "Tom Krajci" 
To: 
Reply-To: "Tom Krajci" 


From: "Mel Bartels" 

>...3/4 inch thick plywood rocker board for an 18 inch scope is very
>minimal.

Yes, it is, but I used as a 'baseline' the recommended materials in the
Kriege/Berry book for that size scope...so some folks may end up making
their scope with similar dimensions.

>...If the error is repeatable, then it can be characterized and removed
by
>software capable of pointing analysis.

Yes, but this is a rather complex error that does not merely create purely
an alt versus az (or similar variation) error...so to properly model and
correct this problem would require you to sample/analyze many points all
about the sky.  I'd prefer to avoid this sort of problem if possible.

My previous work to analyze mount pointing errors in a dob was to:

A. point due south and measure alt versus alt errors (about 6-9 data points)
B. set elevation at about 30 degrees, and measure az versus az errors
(about 36 data points

But that sort of analysis will not properly correct flexure problems in the
rocker box bottom.

Tom Krajci
Tashkent, Uzbekistan


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