Help with HEQ5 guiding results

[Matt Zerbe]

I have been struggling to diagnose some RA issues seen in my guiding for the last several months. I am inclined to believe this is due to my settings in PHD2 or a worm gear issue, due the spikes being periodic. I am just not clever enough to determine which. 

Below is the link to my guide log from last night. I did not calibrate last night but I have recently, the problem does not improve following a recalibration. I also ran a guide assistant last night to see if my values were screwed up. I accepted the suggested values prior to beginning the imaging session. 

Any help would be appreciated! Thank you!

https://openphdguiding.org/logs/dl/PHD2_logs_WhFy.zip

[Bruce Waddington]

Hi Matt.  This looks like it's a problem with the mount, it's not being caused by PHD2.  Here's a look at one of the worst-case guiding sessions (RA in red):

These occur roughly on 10-minute intervals which may correspond with the worm period.  Another view shows how bad it is, this one with guiding corrections removed:

All of this occurred while the scope was on the west side of the pier.  Once you did the meridian flip, the tracking performance improved significantly and these very large excursions disappeared until around 00:24.  The meridian flip would presumably have rotated the worm gear to a different position so there may be a clue there as to where the problem lies.  You should look to see if this side-of-pier dependency has also appeared in earlier sessions.  Of course, having the RA drive system too tightly meshed is always a possible source of these kinds of problems.

Good luck,

Bruce

[Matt Zerbe]

Thanks Bruce, this is very helpful. Upon examination, the motor gears were tight so I readjusted them. Hopefully that resolves the issue. Thanks again!