#21  
Old 18-10-2015, 12:11 AM
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lazjen (Chris)
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I would assume flexing would be caused by problems with weight at these "various angles"? Wouldn't I also see the problem in Dec as well then (which I do not seem to have)?

And how realistic is it to have flexure in a RC10? Or a moonlite focuser?

I should clarify, that except for removing the 0.67 reducer (so it was at approx 1340mm), the set up was the same that I was using for taking 30 min subs before. I wanted to refine the PA further for the change to the 2000 mm, which I thought would be more sensitive to any inaccuracy I had.
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  #22  
Old 18-10-2015, 08:25 AM
bugeater (Marty)
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Quote:
Originally Posted by lazjen View Post
PE can still be part of the problem, just like the seeing will be. It's just that I think we can rule out both as being the major component of the RA problem.

With my next set up I'll be able to leave it in place for a long time, so I'll be able to work through the issue(s) in less of a rush.
If we are talking drift alignment, then you shouldn't pay attention to the RA chart.
If we are talking guiding in the RA axis, then things like PE, seeing and wind will be involved.

I'm envious that you have a permanent setup. It'll certainly reduce the alignment headache once you get it right.
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  #23  
Old 18-10-2015, 09:07 AM
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Slawomir (Suavi)
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Quote:
Originally Posted by lazjen View Post
I would assume flexing would be caused by problems with weight at these "various angles"? Wouldn't I also see the problem in Dec as well then (which I do not seem to have)?

And how realistic is it to have flexure in a RC10? Or a moonlite focuser?

I should clarify, that except for removing the 0.67 reducer (so it was at approx 1340mm), the set up was the same that I was using for taking 30 min subs before. I wanted to refine the PA further for the change to the 2000 mm, which I thought would be more sensitive to any inaccuracy I had.
Fair enough. I might have gotten confused what the issue is in here. From the screenshots you have attached I saw a drift in Dec (red line) indicating either inaccurate alignment or flex under gravity (could be mirror, tubes, focuser...).

At 2000mm any flexture (something not being 100% rigid) will be more noticeable.

Just throwing some ideas into the basket....
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  #24  
Old 18-10-2015, 10:36 AM
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vlazg (George)
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I also have trouble with PHD2 drift alignment tool.
What about EQ Align, doesn't seemed to be mentioned on the forum.
Haven't used it but it seems a simpler process, a bit more accurate than Alignmaster.
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  #25  
Old 18-10-2015, 12:20 PM
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lazjen (Chris)
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Quote:
Originally Posted by bugeater View Post
If we are talking drift alignment, then you shouldn't pay attention to the RA chart.
If we are talking guiding in the RA axis, then things like PE, seeing and wind will be involved.

I'm envious that you have a permanent setup. It'll certainly reduce the alignment headache once you get it right.
With the permanent setup, the wind doesn't affect the mount at all, thankfully. And it got to the stage that if I couldn't have a (semi)permanent setup I think I would have had to pack it all in and give up. I just could not handle the setup/teardown all the time.

I've got everything set up again in the obs, so if tonight has any clear skies I'll start the process again.

Quote:
Originally Posted by Slawomir View Post
Fair enough. I might have gotten confused what the issue is in here. From the screenshots you have attached I saw a drift in Dec (red line) indicating either inaccurate alignment or flex under gravity (could be mirror, tubes, focuser...).

At 2000mm any flexture (something not being 100% rigid) will be more noticeable.

Just throwing some ideas into the basket....
No worries. I have used 2000mm in the past when I was using my DSLR, although I think the maximum guided images I took were 10 min. From memory, the subs were ok, but not great. I'd like to be able to get good images at 30 min, if possible.

Quote:
Originally Posted by vlazg View Post
I also have trouble with PHD2 drift alignment tool.
What about EQ Align, doesn't seemed to be mentioned on the forum.
Haven't used it but it seems a simpler process, a bit more accurate than Alignmaster.
The main reason I haven't tried it is that I don't have a camera it supports, I think. Just checked: Ok, it supports QHY5, hopefully that means QHY5Lii, so I might try that as well.
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