I have been using the Gemini.net ASCOM interface or the physical hand controller to nudge the mount because both of them have STOP buttons. I’ve noticed it’s a necessity.
I have experienced 3 other types of wild slews with my G11. One I can tie to the behavior of PHD2. For instance if I have been imaging a target in SGP and guiding with PHD when I pause the sequence to do a manual focus on a nearby star, I frequently experience a wild slew or mount stutter if PHD is still guiding when I issue the manual slew the star I want focus on. I think that PHD is fighting me in that case and doesn’t know that I have issued a manual “over ride” slew.
I experienced two other wild slews last night. One occurred when SGP had finished with one imaging target in the sequence and started slewing to the next target. The scope just kept slewing until it ran into a limit that I had set in the mount configuration. I have not experienced this type of slew very often.
On another occasion last night when SGP was centering on a target in the sequence the mount started slewing wildly until it ran into a limit. This type of wild slew happens more often than any other that I have encountered. It’s concerning because it means that I really can’t leave the mount unattended and I have had to set the limits tighter than recommended to ensure that equipment and cameras are not damaged by these occasional problems.
I checked the Gemini.net ASCOM object target log and it appears that the RA and Dec coordinates the driver received were OK and not corrupted. This would seem to implicate either the ASCOM driver, the Gemini 2 Losmandy onboard computer/software or perhaps the stepper motor drive circuitry/cables, but not a SGP problem. Not sure how to further debug this.
Anyway, just wanted to apprise you of other potential wild slews you might encounter and I am trying to document them more publically so that we might eventually figure out the root cause and correct them.
On the other hand I experienced the best steady guiding I’ve ever had on my G11 last night, .7 arcsec PE RMS.