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INDI Library v1.8.1 Released (09 Sep 2019)

Monthly maintenance release INDI v1.8.1

polar alignment moved????

4 months 4 weeks ago
Gonzothegreat
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polar alignment moved???? #38146
Last week or so, being at the observatory I was able to achieve a good polar alignment.
See first picture, then tonight I decided to check again from remote.... I don't understand how this can move??




Kstars Mac osx
Odroid C1 running indiserver (kept up-to-date with apt-get update/upgrade)
HEQ5 pro / QHY5 / Atik 314L+
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4 months 4 weeks ago 4 months 4 weeks ago by wvreeven.
wvreeven
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polar alignment moved???? #38205
What do you mean with move? In the first image the polar alignment error is 12", in the second 1'43" and yes that is a difference. Not sure what could have caused that. If you refer to the different star field in the images then the telescope simply is pointed at a different part of the sky.


Wouter

ASI1600MM-Pro Cooled and filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro

ASI1600MM-Pro Cooled and filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R

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4 months 4 weeks ago
Gonzothegreat
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polar alignment moved???? #38207
yes, the image field is pointing to a different part, but it's not that far away from the first picture. Surely the polar error should be the same, no?

Kstars Mac osx
Odroid C1 running indiserver (kept up-to-date with apt-get update/upgrade)
HEQ5 pro / QHY5 / Atik 314L+

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4 months 4 weeks ago
wvreeven
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polar alignment moved???? #38209
Well, if you are 100% and more sure that nothing has touched and moved the mount then I'd say yes, the polar alignment error should stay the same. When you got the 12" polar alignment error, did you park the mount, close the box, opened it again and redo the polar alignment to check and verify that it kept the same alignment error? 12" is much better than 1'43" in terms of polar alignment error but 1'43" is not that different from 12" in terms of physical displacement. I am not trying to imply that you haven't been careful to make sure that all is tightened and stable but there are loads of things that screw up polar alignment. It is hard to tell what could explain the polar alignment error change without having been there physically.

ASI1600MM-Pro Cooled and filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro

ASI1600MM-Pro Cooled and filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R

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4 months 4 weeks ago
Gonzothegreat
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polar alignment moved???? #38213

wvreeven wrote: When you got the 12" polar alignment error, did you park the mount, close the box, opened it again and redo the polar alignment to check and verify that it kept the same alignment error?


That's something I did not do.

wvreeven wrote: 12" is much better than 1'43" in terms of polar alignment error but 1'43" is not that different from 12" in terms of physical displacement. I am not trying to imply that you haven't been careful to make sure that all is tightened and stable but there are loads of things that screw up polar alignment. It is hard to tell what could explain the polar alignment error change without having been there physically.


Could be an imbalance in the imaging gear, too heavy on one side etc.. maybe?
I will be double check it when I'm over there next time.

Kstars Mac osx
Odroid C1 running indiserver (kept up-to-date with apt-get update/upgrade)
HEQ5 pro / QHY5 / Atik 314L+

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4 months 4 weeks ago
nmac
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polar alignment moved???? #38216
I would check that next time, that could be exactly the source of all your problems.

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4 months 4 weeks ago 4 months 4 weeks ago by wvreeven.
wvreeven
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polar alignment moved???? #38217

Gonzothegreat wrote: Could be an imbalance in the imaging gear, too heavy on one side etc.. maybe?
I will be double check it when I'm over there next time.


Yes, that is exactly what I mean. See also nmac's comment.

EDIT Recently I was made aware of this presentation about the importance of balancing your astro gear .

ASI1600MM-Pro Cooled and filter wheel with a SkyWatcher Esprit 80 ED on a SkyWatcher HEQ5-Pro

ASI1600MM-Pro Cooled and filter wheel with an 8" TS Ritchey-Chrétien on a SkyWatcher EQ6-R

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4 months 4 weeks ago
pentaxian23
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polar alignment moved???? #38233
We noticed that the PA was not consistent unless you always start from park and always move in the same direction during the process. Also, one problem was a pin that the az bolts pinch. It was not solid. The HEQ5 mount does not have a pin but a boss instead that is part of the structure so it can't move. But I'd say you have something not screwed down solidly - like the house! Haha - sorry just kidding.

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4 months 4 weeks ago
Gonzothegreat
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polar alignment moved???? #38235

wvreeven wrote:

Gonzothegreat wrote: Could be an imbalance in the imaging gear, too heavy on one side etc.. maybe?
I will be double check it when I'm over there next time.


Yes, that is exactly what I mean. See also nmac's comment.

EDIT Recently I was made aware of this presentation about the importance of balancing your astro gear .


Interesting presentation, I always tried to balance the RA first, I shall try this method next time.

Kstars Mac osx
Odroid C1 running indiserver (kept up-to-date with apt-get update/upgrade)
HEQ5 pro / QHY5 / Atik 314L+

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4 months 4 weeks ago
Ihoujin
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polar alignment moved???? #38249
If you were to use phd2 for an evening, you can use the logs to measure your polar error based off the corrected drift. It could serve as an independent test.

INDI/KStars on Raspberry Pi 3B+
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Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG @280mm Guide Scope
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Adafruit Motor Hat shield
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Startech 7 port powered USB Hub.

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4 months 4 weeks ago
knro
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polar alignment moved???? #38250
I have been asking for this for a long time.. I never really measured PAA against any other method.

Jasem Mutlaq
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4 months 4 weeks ago
Ihoujin
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polar alignment moved???? #38258
Jasem. Based off of what I have seen, the polar error reported by PHD2 agrees almost exactly with the remaining error I have after the PAA routine. At least within ± 10 seconds

INDI/KStars on Raspberry Pi 3B+
Lubuntu 16.04
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG @280mm Guide Scope
PHD2
Adafruit Motor Hat shield
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
The following user(s) said Thank You knro

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