Astroberry/Kstars/Ekos alignment problem with near due south stars

[peterstmsloan]

Hello,

I have a nicely working imaging system controlled through Ekos. I can get the plate-solving and alignment working perfectly for, say M101 (nearly straight up at the moment) to within about 15 arcsecs. BUT when pointing at star WASP-43 (to record a exoplantery transit) that is presently nearly due south and close to the horizon, I find the following:

• The initial slew is about 1000 arc sec away from the target.
• Plate solving works and it computes a correction factor
• But after those corrections are sent to the mount and it re-solves a new image it turns out it hasn't moved. 
• Around and around this loop, but the scope never moves.

We ended up using the handset to position the scope to allow the transit to be recorded. So the telescope can reach this target - the question is why is doesn't get this automatically?

The set up:

• EQ6 Pro mount with SynScan handset (v4 of the firmware)
• Recently (1 month ago) updated Astroberry/Kstars/Ekos
• The Pi is plugged into the SynScan handset by USB.
• We have a roll-top observatory with permanent aligned pier.
• The mount-scope are polar aligned accurately using the polar-alignment tool in Ekos.
• Battery powered.

We've tried various different batteries to make sure the input voltage to the mount is 12 V. Still get this problem. We've slackened the cabling to ensure there is no tightening at the extreme orientation needed for WASP-43. We've re-balanced the system. Nothing seems to solve this issue. 

The system then works perfectly for, here M101, slews, aligns, and guide allowing 10 min exposures.

Any one have a clue why due south is such an issue? Or has seen similar behavour?

Peter

 

Edited May 1, 2022 by peterstmsloan
Spelling

[michael8554]

Flip or Limits settings ?

Michael

[dph1nm]

I have had a similar problem immediately after a meridian flip (this with an EQ8). Solver finds the offset, says it is moving the scope but it doesn't. So the next solve finds exactly the same offset (and so on).  Weirdly, choosing another target just a few arcminutes away solves and centres OK, but if you then return to the original target is still won't move the scope.  I put it down to a bug in ekos/indi and moved on to another target. It isn't the only problem I have found with the solver, but, hey, its free!

NigelM

[wimvb]

On 01/05/2022 at 21:09, peterstmsloan said:

Hello,

I have a nicely working imaging system controlled through Ekos. I can get the plate-solving and alignment working perfectly for, say M101 (nearly straight up at the moment) to within about 15 arcsecs. BUT when pointing at star WASP-43 (to record a exoplantery transit) that is presently nearly due south and close to the horizon, I find the following:

• The initial slew is about 1000 arc sec away from the target.
• Plate solving works and it computes a correction factor
• But after those corrections are sent to the mount and it re-solves a new image it turns out it hasn't moved. 
• Around and around this loop, but the scope never moves.

We ended up using the handset to position the scope to allow the transit to be recorded. So the telescope can reach this target - the question is why is doesn't get this automatically?

The set up:

• EQ6 Pro mount with SynScan handset (v4 of the firmware)
• Recently (1 month ago) updated Astroberry/Kstars/Ekos
• The Pi is plugged into the SynScan handset by USB.
• We have a roll-top observatory with permanent aligned pier.
• The mount-scope are polar aligned accurately using the polar-alignment tool in Ekos.
• Battery powered.

We've tried various different batteries to make sure the input voltage to the mount is 12 V. Still get this problem. We've slackened the cabling to ensure there is no tightening at the extreme orientation needed for WASP-43. We've re-balanced the system. Nothing seems to solve this issue. 

The system then works perfectly for, here M101, slews, aligns, and guide allowing 10 min exposures.

Any one have a clue why due south is such an issue? Or has seen similar behavour?

Peter

 

 

20 hours ago, dph1nm said:

I have had a similar problem immediately after a meridian flip (this with an EQ8). Solver finds the offset, says it is moving the scope but it doesn't. So the next solve finds exactly the same offset (and so on).  Weirdly, choosing another target just a few arcminutes away solves and centres OK, but if you then return to the original target is still won't move the scope.  I put it down to a bug in ekos/indi and moved on to another target. It isn't the only problem I have found with the solver, but, hey, its free!

NigelM

Have either of you posted this problem on the indilib forum? One of the developers might be able to help.

[JonCarleton]

What is the setting for your target precision?