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Drift Alignment frustration

polar alignment
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#1 Quoth

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Posted 24 January 2021 - 07:56 PM

Hi all,

 

I was hoping someone could give me some assistance after I spent about 2 hours last night tearing my hair out and missing out on a couple of objects I really wanted to see.

 

Requisite southern hemisphere note here so no Polaris.

 

Last night, I set up my ED80/HEQ5 Pro and got it pointing south; 3 star alignment off Sirius, Acrux and Rigel; found the error; went to drift align off Sirius and that's where it all went wrong. I got Sirius mostly centre in the eyepiece then hit the button to start the drift alignment, heard a rather loud whir and the telescope seemed to move a lot more than I expected, checked the eyepiece...no Sirius. Okay, the page I was using said that might happen even though I had a 32mm eyepiece in there for the widest possible view. It said if that happened to check the finderscope for a wider field of view. Checked the finderscope...not there either when I'm supposed to be adjusting the T-bolts. I had a bit of a fiddle with the T-bolts to see if that might bring it back in view and...it made the error worse. Same with the knobs. Nothing I did seemed to get any kind of success and every alignment came back with a worse error than the last time, I think at one point I was out by 34 minutes, minimum of around 6 - 8 minutes.

 

I spent a good couple of hours trying to figure out this issue with no success so I did another 3 star alignment and just adjusted the view whenever the Orion Nebula was drifting out of centre, but I couldn't use it to view anything else :( I was really hoping for some trickier objects last night like Flame and Horsehead.

 

Can anyone offer any suggestions or advice on how to potentially correct this problem? I'd really like to know what I was doing wrong. Not having Polaris to align on is frustrating but them's the pains of being down under, I'm just hoping that I can rectify this issue so I can properly use my new toy (camera).

 

Thanks!



#2 michael8554

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Posted 25 January 2021 - 09:06 AM

According to this the first adjustment is with the handset, not the T-bolts:

 

https://www.cloudyni...n-sirius-mount/



#3 Quoth

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Posted 25 January 2021 - 11:13 AM

According to this the first adjustment is with the handset, not the T-bolts:

 

https://www.cloudyni...n-sirius-mount/

That's the process I followed, I got to step 6 and the reference star was completely gone out of both fields of view, eyepiece and finderscope.



#4 sevenofnine

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Posted 25 January 2021 - 02:27 PM

My tracking got better when I did this. Use a high power eyepiece for your alignment. A zoom eyepiece works good if you have it. Center the star in the eyepiece. Now defocus the star until it becomes a large white blob. Re-center the white blob until the black area around it is equal all the way around. Quickly hit enter. Do the same procedure on the second star. I normally start with Polaris so my first star is much easier. You will have to work quickly. If this doesn't help then look for something called PAE (pointing accuracy enhancement) in your manual or sub menu on the hand controller. This allows you to slew to a known object to fine tune the alignment. Good luck waytogo.gif



#5 JorgeDeAroGarcia

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Posted 25 January 2021 - 08:57 PM

To align the mount in the southern hemisphere you will need an eyepiece with a reticle (illuminated or not) and if it is double like the SkyWatchers better, they usually have short 9/12 mm focal lengths.  It seems silly but maybe the error is in its location, to give the correct data to the mount at altitude.  Initially it is a tedious process and it takes time, then it is done very quickly.  Another thing ... if you do not do astrophotography, the GoTo is not so demanding in the station setting.  There is a summary, I hope it serves you.  Cheers and clear skies!  😀

 

Screenshot_20190303-050842_1.png



#6 bignerdguy

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Posted 26 January 2021 - 02:23 PM

I see two possible issues:

 

1) you are not properly polar aligned.  you might need to go back and redo the polar alignment.  

2) your three star alignment was done using the wrong stars.  If you do a manual choice of the 3 stars and not from the auto suggested list (you have automatic selected list turned off in the HC) then you may have chosen the wrong stars that were either too far apart or too close together or too high or too low in the sky.  Star choices should be between ~25 Deg low and 55 Deg high and roughly 30 degrees apart for the first two.  If you use the automatic list option then all the stars selected will be correct and this should not be an issue.  However, try using different stars anyway for your initial alignment and don't choose something tool ow or high in the sky, about middle low to middle high works best I have found for my mount (Orion Sirius EQ-G/HEQ5).  Also don't use Sirius for the drift star as it is too bright, use something a little dimmer for the alignment star for better accuracy.




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