Better guiding one side of the meridian

[Chris Pendred]

Hi Bruce and team

Since you helped me with the camera settings I have had a go a slightly loosening the bearings for both axes and both axes are gliding much better and I believe this has addressed the stiction you mentioned previously.

I've done a further set of 20 minute logs either side of the meridian.

It looks like the second set is much better than the first set however both sets are better than any I had previously. I'd like to understand why. Is it a slight difference in balance ?

I'd appreciate it if you could please  review the logs and provide any recommendations for improvements.

https://openphdguiding.org/logs/dl/PHD2_logs_8dpG.zip

Thanks in advance

Kind regards

Chris

[Bruce Waddington]

I don't think there's much that can be said about this.  Once you're guiding behavior is down below 1 arc-sec total rms, your results will increasingly be affected by changing seeing conditions.  Your total rms while pointing west was 0.73" vs. 0.9" while pointing east.  But looking at the RA and Dec components of that total, the Dec behavior was 33% worse in the east while the RA was only 21% worse.  The Dec numbers are not strongly affected by the mount mechanics because the Dec motor is mostly idle, so they generally reflect seeing or unusual things like vibration.  Bottom line, I don't see anything here to suggest that anything needs to be done with the mount.  I think a better question is whether your imaging results, over a long period of time, are negatively affected by any sort of side-of-pier dependency.  There's no point in just chasing numbers here.

Regards,

Bruce