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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

Guiding issues near zenith

  • Posts: 149
  • Thank you received: 10
Hello,

I always have guiding problems near the zenith. Yesterday I was observing M31 and it worked flawless with guiding variation around 1". Today I tried IC5067 (pelican nebula) which is right now close to the zenith and I canÄt even finish guiding calibration. I had that in the past and I wonder, if my mount is defect or if there are any settings to change.

I am using the EQ-6R with a very lightweight wide field set up currently and the RA calibratrion fails.

2018-10-11T22:03:26 GUIDE_RA: Scope cannot reach the start point after 35 iterations. Possible mount or backlash problems..

any hints?

Regards

Amin
Skywatcher Newton 200/1000, Sharpstar 60ED, Canon Lenses
Skywatcherr EQ-6 R, AZ-GTI
StellarMate @ Raspberry Pi 3B+
ASI 183 MC Pro
ASI 290 MC guiding cam on APM 60 ImageMaster
Sesto Senso 2 Focuser + Astromechanics Canon Focuser

Last edit: 5 years 5 months ago by Amin Sharaf.
5 years 5 months ago #30311

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Are you sure that:
- you are using the guide cam and guide telescope in the guide module
- you entered the focal length of the guide telescope correctly
- you entered the CCD specs (number of pixels and pixel size) correctly
- you did a real good polar alignment

If all yes, how do you connect your mount to INDI? SynScan, SynScan with PC direct mode, EQDir/Mod cable?
The following user(s) said Thank You: Jasem Mutlaq
Last edit: 5 years 5 months ago by Wouter van Reeven.
5 years 5 months ago #30313

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Hello wvreeven,

thanks for the quick reply. I am pretty sure, it has nothing to do with the things you mentioned. I just tested again with an object near 30° height, calibration works like a charm. back to the zenith it fails.

I am using a stellar mate with the Indi_eqmod_telescope driver. The mount is connected via the PC-direct cable (lynx) to the raspberry.

Regards

Amin
Skywatcher Newton 200/1000, Sharpstar 60ED, Canon Lenses
Skywatcherr EQ-6 R, AZ-GTI
StellarMate @ Raspberry Pi 3B+
ASI 183 MC Pro
ASI 290 MC guiding cam on APM 60 ImageMaster
Sesto Senso 2 Focuser + Astromechanics Canon Focuser

5 years 5 months ago #30315

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Now the object is a bit more away from the zenith and calibration worked. Guiding deviation 0.8".
Skywatcher Newton 200/1000, Sharpstar 60ED, Canon Lenses
Skywatcherr EQ-6 R, AZ-GTI
StellarMate @ Raspberry Pi 3B+
ASI 183 MC Pro
ASI 290 MC guiding cam on APM 60 ImageMaster
Sesto Senso 2 Focuser + Astromechanics Canon Focuser

5 years 5 months ago #30316

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well, isn't this a classic Zenith inbalance problem then from the looks of it? When the mount reaches zenith, the loading on the gear changes and they are not as securely meshed as before. This is at least one of the primary reasons for this behavior.
5 years 5 months ago #30320

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Hello Jaseem,

okay, thanks for the confirmation, so I know what to do, tilt the earth a bit ;-)

Cheers

Amin
Skywatcher Newton 200/1000, Sharpstar 60ED, Canon Lenses
Skywatcherr EQ-6 R, AZ-GTI
StellarMate @ Raspberry Pi 3B+
ASI 183 MC Pro
ASI 290 MC guiding cam on APM 60 ImageMaster
Sesto Senso 2 Focuser + Astromechanics Canon Focuser

5 years 5 months ago #30321

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There are many suggestions online on how to "imbalance" the weights to reduce this effect. It also depends on the mount and the polar alignment, so I never had to worry about this with my EQ8.
5 years 5 months ago #30324

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