Guiding goes crazy after meridian flip

[Jack Bernstein]

I have had some issues with guiding with my somewhat new rig using a QHYMinicam, a QHY OAG and a ASI220MM. To my eyes, stars are relatively tight with the minicam (which is guiding at 644mm, the same focal length as the main scope). After the meridian flip (at ~0244 10/14), I had runaway dec drift and it never recovered. Last night, I could never get it well aligned and I was not really able to image. 

I have read the documentation but I am obviously doing something wrong. Any help would be appreciated.

Equipment:

Mount - EQ6R-Pro
Scope: AT115EDT at 644mm
Camera: QHYMinicam8 main camera and ASI220MM guide (using an OAG)

Software PhD2 + NINA + Green Swamp Server for mount.

[Rick Cohen]

Try searching this forum for "Reverse DEC output after meridian flip".  There's a setting for that in the advanced (brain) menu under the Guiding tab.

And the experts usually like to see both the PHD2 guide AND debug logs.  You can upload those to this forum using the appropriate menu item in the PHD2 Help menu.  The upload will give you a link to paste into a forum post.

[Jack Bernstein]

Here is a link to all the logs.

https://openphdguiding.org/logs/dl/PHD2_logs_PTxu.zip

[Brian Valente]

>>> After the meridian flip (at ~0244 10/14), I had runaway dec drift and it never recovered. 

you need to change your reverse dec after meridian flip setting. 

 

you can also run the calibrate meridian flip tool and find this for yourself

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Brian Valente

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[Brian Valente]

PS

I'm not sure what documentation you referenced, but the built-in help includes the following:

'Reverse Dec output after meridian flip' -  tells PHD2 how to adjust the calibration data after a meridian flip.  Some newer mounts track their 'side of pier' state and automatically reverse the direction of the declination motor after a meridian flip.  Older mounts do not do this.  In either case, PHD2 needs to know if the mount will automatically change its behavior based on side-of-pier.  You may have difficulty finding information about how your mount behaves in this respect, so PHD2 provides the Meridian flip calibration tool to determine the correct setting automatically. It's also easy to figure out the setting manually with this quick experiment:

With the checkbox disabled, calibrate on one side of the pier, then move the mount to the other side.

If you are guiding via ASCOM or Indi or are using an 'aux mount' connection, just start guiding.

If you're guiding only via ST-4 and PHD2 has no scope pointing information, first select 'Flip Calibration' under the 'Tools' menu, and then start guiding.

In either case, if the guiding works normally, leave the box un-checked; but

if you see guiding run-away in declination, check the box and repeat the entire procedure, including calibration.  You must repeat the procedure, simply checking the box doesn't "fix" anything.
 Note: this procedure must be following in its entirety until you determine the correct setting.  Changing the 'Reverse Dec' setting only determines what will happen in the future, at the next calibration.  

[Jack Bernstein]

Will do this next clear night. I checked my 'run away dec'  for the last 2 nights and they were both right after the meridian flip.