Hmm, looks quite strange. The first thing I would do, is check all nuts, bolts and grub screws that fasten drive gears to shafts and worms etc, to make sure that one hasn’t slightly worked loose and is allowing a gear to slip on a shaft in an ad hoc manner.
Im no G11 expert, however experience in my proffesion has taught me that when ever you have a closed loop type system that fails, you have to open the loop and fault find from there. In this instance stevie wonder could tell you that the guiding is stuffed. A simple way of isolating it to either mechanical or electronic could be unplug the auto guiding and see what the mount comes up with by itself over a minute or two. You may find that the guiding is not perfect but it definitely is somewhat better in a way, and you may not. The only experience I have had with images that look like this was a mount that had faulty electronic operation. The tracking would be ok until the system started making huger error corrections to try and get the guide star back.
If you get an identical result then you probably needn't look at the error correction side.
Wild guiding if you ask me. And in two axes as well, not just "no guiding" so elongated stars, but a bit of both. What is the guide camera Leon? While it is possibly not in your case, some guide (or think they are) on a hot pixel.
Guide-scope not loose?
I've had similar results when i first starte guiding and it turned out to be the settings I had in PHd. Might not be your problem but that what it was for me. check that you havent changed any settings by mistake.
Looks like PHD lost the guide star temporarily and then corrected for it?
Thats quite a shift in position though, and the drift would have been bad to move that much.
Guidescope secured correctly? Guiderings not tight enough ?
Frustrating is right, and more so now that it is wet and cloudy so I can't even get out there and try and fix it.
Gary, it is very weird indeed, but i feel it will have a simple explanation, I hope.
Gary I use the Orion StarShoot, and it has performed perfectly until now.
Leon, the best thing about the G11 is its modular design. It's like LEGO blocks. You can pull it apart in 5min and put it back together in 10. If you've never opened it then the most likely culprit is clutch slippage. The nylon discs get greasy over time. The grease will come from the bearings, mostly in RA. You don't even have to take the worms out to rectify this. Unscrew the knob at the end of each axis and take off the thrust bearings at the end of each shaft and slide off the axis. You'll see the discs. Give them a good clean with a rag and alcohol if necessary and try again, see if it makes things better. I actually glued mine on the bearing side with rubber Gel Grip to get higher break away friction.
Are you using PHD? There has been a bit of a thread on the Stark labs website about people's guiding going off for no apparent reason.
Yeah I've noticed that for the past couple of months. Loads of heated discussions about it. Since the 1.10.x batch of PHD was released. I have also noticed PHD is a bit more aggressive in RA and "slacker" in correcting DEC with the default settings but tweaking the parameters fixed all that. Most of guiding errors were mechanical or balancing on my end, not the software. Have you had issues with the GM8 and PHD?