I have been testing with NextStar 6SE Alt/Az and everything works BUT after slewing to a target the scope hunts up and down sometimes 10 to 15 times before it settles. This is a problem when plate solving is taking multiple exposures to refine the solve.
This is strange. It is supposed to be:
1. Fast GoTo to the position the object *was* at one minute ago
2. Slow GoTo to the final position
This is intended to cancel out any backlash by not changing direction on approach
It should never "hunt around". Are you sure you are not running alignment tool from EKOS in the "slew to target" mode?
On my last session under stars, I had similar issue. There was bad alignment calculation that gives me average of ~400arcsec error on goto and solve new image. After running "slew to target" in ekos alignment tab, function was not able to get error small enough jumping around and finally gave up. There was one time when error was not decreasing but increasing with every one try.
I believe this behavior is related to alignment issue that developers are aware, and trying to resolve it. Lets just give them time.
I have noticed this problem. This is indeed problem with alignment subsystem. Workaround for now is increasing the accuracy setting to realistic value (few arcmin). It starts to be usable - currently the driver is simply unable to get 30 arcsec goto accuracy. We are working on it. The other way is to switch to "sync on solution". Note that 1arcmin pointing accuracy is the error of the size of the Jupiter disc, so fairly small.
I spoke to soon Jochym, 10 minutes ago I did a normal GoTo and the scope is still hunting up and down.
Could it be something to do with tracking? as it is "slewing with tracking"
The hunting starts as soon as tracking turns back on after the slew. If one turns off tracking while it is hunting the hunting stops. If you turn tracking off and then quickly on again the hunting starts again. If you turn tracking off and wait about 5 seconds before turning it back on the hunting stops.
This doesn't happen for every goto but if I do goto's between Mizar and Alioth (in Ursa Major) it happens about 70% of the time. Nothing special about these two target except that they are close together and further testing doing goto's between other close targets shows that this seems to be the problem. This is probably why "slew to target" in the aligment tool shows the problem because it is just making small goto moves. A bit further testing and I can get the hunting virtually 100% percent of the time if the angular distance between the start and finish target is less than about 2 degrees.
Is there a setting for the settle time before tracking starts after a slew?
I hope this helps, if you want me to try anything just ask, I am a software engineer so can poke around in code if required.
Ken
P.S. I have tried putting a 10 second delay in the code (sleep(10) after the goto before turning tracking on but it doesn't help, as soon as the tracking kicks in the hunting starts. Manually stopping tracking for 10 seconds and re-starting tracking fixes it.
So as they say ASSUME makes an ass out of u and me.
AstroGene1000 was correct it is backlash settings on the scope that is causing the problem, I zeroed all the backlash settings and now I can't get it to hunt on a goto.
So I think this issue is closed but a note needs to go in the driver details that the backlash settings on the scope can cause this behaviour.