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Old 08-07-2013, 09:26 AM
Barrykgerdes
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Barrykgerdes is offline
 
Join Date: Feb 2007
Location: Beaumont Hills NSW
Posts: 2,900
Quote:
Originally Posted by Merlin66 View Post
Barry,
With a GEM, I'm not sure I agree....
The final outcome is to get the optical axis of the OTA parallel with the RA axis.?
No orthogonality is to get the declination rotation axis perfectly orthogonal to the RA axis. Shimming the dovetail will only to get rid of the OTA cone error, it will not correct orthogonality, that can only be done by correctly aligning the declination and RA axes.

Quote:
This can be achieved by shimming the mount joints or by doing the same with the saddle/ rings/ OTA - the SW method of "cone" correction - push pull screws at the ends of the dovetail/ rings should work
This is cone error correction not orthogonality

Barry
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