Flexure?

I am taking photos through my fork-mounted Meade 14", at a scale of about 1.39" per pixel.

I am guiding with a 80mm APO piggy backed on the Meade.

Although my guiding error graphs are tight, I keep getting elongated stars along the RA axis.

Would this be a sign of flexure? Should I try off-axis guiding?

Your thoughts are appreciated.

Flexure is the most likely culprit with RA elongation. It can be in the focuser where the camera is mounted or the guide scope setup.

Where are you pointing when you see these errors? Overhead?
East? West? South?

Are you aligning and stacking sub-exposures?
How long are your sub-exposures?

If you are pointing east or west, then I think flexture could
indeed be the problem. If it is flexture, going to shorter
sub-exposures (like half or third as long) might fix it.
This would be one way to test for flexture. Off-axis
guiding would fix it.

If you are pointing overhead or south, and have reasonably short
sub-exposures, I am inclined to suspect some oscillation in
the drive gearing with few seconds or less period. If this
is the case, you would need to make some adjustments to the
gearing or balance of the scope.

Flexure is one suspect.....mirror flop could be another.

Does this go on for hours and hours, or does it eventually settle out?

Alex