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Old 09-10-2020, 05:40 PM
Gasmanwill (Will)
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Southern Hemisphere Drift Alignment Guide - 1st post

Hi to everyone out there

This is my first post and introduction to IIS.

Years of photography, only a few days of astro. I live in Fremantle WA. No view of SCP from my garden and too close to the harbour to look west
currently collecting gear at a good pace...

Taking my time to get under the stars 1) because of the cloud cover recently and 2) because i have just bought an Altas Pro azeq and i'm reading and trying to understand mount setup etc from first principles rather than just hitting "align" on my computer!

Limited web info that i could understand on SCP drift alignment so I thought I would write myself a guide, then I thought I would share it to ask for comments and suggestions possibly with a view to talking it though on a video in Youtube. Apologies, I diddn't look very hard on this forum.

Please think of this as a first draft, you can be brutal I have broad shoulders!

Cheers, hopefully some of you may find this helpful and I will meet some of you in due course.

Will
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File Type: pdf SCP Drift Alignmnet.pdf (253.3 KB, 65 views)
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Old 15-10-2020, 10:16 AM
AdamJL
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Hi Will

Welcome! You'll find this isn't a very "busy" forum, so don't be discouraged by slow replies. Cloudy Nights has a bigger audience, but less focus on Australian skies.

Thanks for the guide. I'm an absolute newbie at this too, so your research is really appreciated, especially as it's a subject I don't understand (boy there are lots of those!)

Cheers
Adam
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Old 15-10-2020, 11:33 AM
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Nikolas (Nik)
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i use a polemaster and/or sharpcap pole alignment but for those who don't have a clear view of the southern pole this guide would be useful.
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Old 15-10-2020, 11:44 AM
rrussell1962
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I found this site a very useful resource on drift aligning.

http://shadycrypt.com/pages/Polar/Polar.htm
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  #5  
Old 15-10-2020, 11:57 AM
Startrek (Martin)
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Will
Welcome to IIS
Your Atlas pro mount is made by Orion telescopes I assume , which is effectively a Chinese mount made by Synta. If it has a Synscan handcontroller Version 3 , 4 or 5 this handcontroller has a feature to polar align without a view of the SCP
All you need is 2 fairly bright alignment stars within 10 to 30 deg Azimuth and on the same side of the south meridian line and anywhere between 35deg and 65deg in Altitude. Drift alignment is fine but laborious, the Synscan method can be done in 5 or 10 minutes once you master it
You can either use an illuminated reticle eye piece to do your alignments or on a laptop using capture software (with zoom )
I have a procedure for this Synscan polar alignment routine and many IIS members just starting out have used it successfully
Before you can polar align you must ensure a few steps are done to get your telescope and mount ready like -
1/ Tripod set level NSEW on hard surface and aligned to True South ( not magnetic south )
2/ Mount head fitted set to “Home position”
3/ Telescope / mount fitted with counterweights all accessories and balanced in Dec and Ra then set back to home position
4/ Altitude of telescope / mount set to local altitude

Recommend you download a free copy of Stellarium on your laptop or desktop to learn the night sky. It can also be used with other software to remotely control your telescope later ( EQMOD )

I have procedures for all of the above plus the Synscan polar alignment routine if you wish to go down that path to polar align

Cheers and enjoy our hobby
Martin
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Old 15-10-2020, 01:19 PM
AdamJL
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Quote:
Originally Posted by Startrek View Post
Will
2/ Mount head fitted set to “Home position”
G'day Martin

I've seen this mentioned before, but what exactly does it mean? I've never had a "home position" menu on my SynScan that I could see? (EQ6-R).

When I've "parked the scope" at the end of a session (not even sure why I do this, considering I take it apart when done..), the axes are never centred.
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Old 15-10-2020, 01:49 PM
Startrek (Martin)
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Originally Posted by AdamJL View Post
G'day Martin

I've seen this mentioned before, but what exactly does it mean? I've never had a "home position" menu on my SynScan that I could see? (EQ6-R).

When I've "parked the scope" at the end of a session (not even sure why I do this, considering I take it apart when done..), the axes are never centred.
Home Position is not primarily a function of Synscan
Home Position is the mechanical position of your mounts axis at the start of a session and end of a session. It sets the mount at a fixed starting point close to the PA position so that when the mount is polar aligned and the Alt and Az are adjusted to PA , the Synscan will save the alignment data and return the mount mount back to that position again or “home position”
If you strip down and set up each night it’s still good practice to set home position as then if you lose power or your Synscan fails you still have the mounts mechanical axis set to start again from that home position. Plus you know the mount will return back to home and not crash into your tripod legs on the same side of the meridian
Does the above make sense !

I also set Home Position ( starting point ) on my 12” Goto AZ dob although it’s a different process than an EQ mount
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Old 15-10-2020, 02:00 PM
Startrek (Martin)
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Originally Posted by AdamJL View Post
G'day Martin

I've seen this mentioned before, but what exactly does it mean? I've never had a "home position" menu on my SynScan that I could see? (EQ6-R).

When I've "parked the scope" at the end of a session (not even sure why I do this, considering I take it apart when done..), the axes are never centred.
Another reason to set home position is once home position is set and your Ra and Dec green rings are locked in at zero with the pointers or arrows , when your mount returns back to home posting after a session and the pointers are not back at zero , this tells you the Ra or Dec clutches have slipped and your alignment will be out if you start another session again. It has happened to me on a few occasions scratching my head why the scope didn’t end up exactly in the centre of a particular star like it did say half an hour ago after starting from home position again. Looked at the dec and ra rings and the pointers were off 5 or 10 degrees so picked up the problem straight away !!
Make sense !
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Old 15-10-2020, 06:07 PM
AdamJL
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Originally Posted by Startrek View Post
green rings are locked in at zero with the pointers or arrows
haha, whoops! I've never ever paid attention to these
I guess they are necessary then?
All I've done in the past (because I can see the SCP) is polar align with Polemaster, 1 star aligned to Jupiter, away I go.
I'm such a noob.
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Old 15-10-2020, 06:34 PM
Startrek (Martin)
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Originally Posted by AdamJL View Post
haha, whoops! I've never ever paid attention to these
I guess they are necessary then?
All I've done in the past (because I can see the SCP) is polar align with Polemaster, 1 star aligned to Jupiter, away I go.
I'm such a noob.
Adam
Here’s my procedure to set Home Position

Home Position on your HEQ5 , EQ6 ,EQ6-R and AZEQ6 ( also refer to AZEQ6 manual as well ) Telescope Mount

1/ Level your tripod pointing to the SCP
2/ Install the mount head and ensure the counterweight shaft is pointing down towards the south tripod leg
3/ Set you Altitude on the mount using the altitude adjusting bolts (Long chrome bolts with thumb tabs ) to the latitude of your current location
4/ Ensure the Azimuth bolts ( black knobs) are screwed in and equally spaced each side of the mount and tighten ( finger tight only )
5/ Do not install the counterweights yet
6/ Stand behind the mount looking south , release the RA clutch and rotate the mount anti clockwise until the counterweight shaft is level . Use a builders bubble float level to check and then lock the RA clutch
7/ Release the RA clock ring and rotate it anticlockwise until the pointer reaches 6.00 (18.00) don’t tighten up yet
8/ Unlock the RA clutch and rotate the RA axis back to the home position and lock it when the pointer reaches 12.00. Lock the RA clutch
9/ Unlock the Dec clutch and rotate the Dec axis until the saddle is exactly level .Check with a bubble float level then lock the Dec clutch
10/ Release the Dec clock ring and rotate it until it lines up with the pointer at 90 deg. Don’t tighten up yet
11/ Unlock the Dec clutch and rotate it anti clockwise until “0” on the Dec lock ring lines up with the pointer then lock the Dec clutch
12/ The Mount should be now in the “Home Position”
13/ Rotate both RA and Dec clock rings so the pointer lines up with “0” and screw down the clock rings
14/ You are now ready to install your counterweights and balance your telescope

Cheers
Martin
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Old 15-10-2020, 08:10 PM
morls (Stephen)
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I've been using a different way to set the DEC home position, one which is done with the scope and counterweights in place.
- Following Martin's procedure, I complete step 7 then lock the RA scale;
- Keeping the RA clutch tightened and the RA axis horizontal and level, I then rotate the telescope on the dec axis until it is level, measuring with spirit level;
- Lock the DEC clutch;
- I set the DEC scale to (90 minus latitude). I'm in Melbourne, so this is 90 - 38 = 52.
- I then lock the DEC Scale, loosen the clutches and rotate the axis to read RA = 0 hours, DEC = 90 degrees.
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Old 06-11-2020, 03:31 PM
AdamJL
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Quote:
Originally Posted by Startrek View Post
Adam
Here’s my procedure to set Home Position

Home Position on your HEQ5 , EQ6 ,EQ6-R and AZEQ6 ( also refer to AZEQ6 manual as well ) Telescope Mount

1/ Level your tripod pointing to the SCP
2/ Install the mount head and ensure the counterweight shaft is pointing down towards the south tripod leg
3/ Set you Altitude on the mount using the altitude adjusting bolts (Long chrome bolts with thumb tabs ) to the latitude of your current location
4/ Ensure the Azimuth bolts ( black knobs) are screwed in and equally spaced each side of the mount and tighten ( finger tight only )
5/ Do not install the counterweights yet
6/ Stand behind the mount looking south , release the RA clutch and rotate the mount anti clockwise until the counterweight shaft is level . Use a builders bubble float level to check and then lock the RA clutch
7/ Release the RA clock ring and rotate it anticlockwise until the pointer reaches 6.00 (18.00) don’t tighten up yet
8/ Unlock the RA clutch and rotate the RA axis back to the home position and lock it when the pointer reaches 12.00. Lock the RA clutch
9/ Unlock the Dec clutch and rotate the Dec axis until the saddle is exactly level .Check with a bubble float level then lock the Dec clutch
10/ Release the Dec clock ring and rotate it until it lines up with the pointer at 90 deg. Don’t tighten up yet
11/ Unlock the Dec clutch and rotate it anti clockwise until “0” on the Dec lock ring lines up with the pointer then lock the Dec clutch
12/ The Mount should be now in the “Home Position”
13/ Rotate both RA and Dec clock rings so the pointer lines up with “0” and screw down the clock rings
14/ You are now ready to install your counterweights and balance your telescope

Cheers
Martin
I haven't posted in a while, and it's been wet and awful in Sydney of late, but just wanted to pop in and say thanks for this.
I'll give it a go as soon as I can setup outside and image again.
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Old 06-11-2020, 04:19 PM
Wilsil (Wilco)
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I never used the setting rings. I tried the first time and when moving the declination back to home, it was binding on the ring.
Never had the need to use it.

Although I am always using the Home/park location.
This is also important when using Stellarium to control your mount as if I understand it correctly, the RA/Dec location is taken from the mount.
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Old 06-11-2020, 07:14 PM
Startrek (Martin)
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Wilco
The polar aligned “Home Position” is important for most telescope control software ( eg EQMOD and Stellarium) as it provides a frame of reference or pointing model to your first alignment Star or alignment point once centred.After that first alignment point the software ( mount) knows exactly where it started from so when you finish your session the mount will return back to it’s starting point or “home position” ready for another session.The alignment data is usually saved in the mount until you switch power off.The more expensive mounts save the alignment data even when the power is switched off.
In the case of EQMOD and Stellarium, the more alignment points or alignment stars that are centred and saved ( Syncronised or Sync’d ) around the night sky , the more you create a sophisticated pointing model and the more accurate your Goto’s become. On most imaging nights I usually only need to Sync 3 to 5 alignment points to easily and accurately find objects.
Cheers
Martin
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Old 09-11-2020, 03:10 PM
AdamJL
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Quote:
Originally Posted by Startrek View Post
On most imaging nights I usually only need to Sync 3 to 5 alignment points to easily and accurately find objects.
Cheers
Martin
Hi Martin

Are you referring to Star Alignment here?
That's interesting, as I tend to only do 1 star alignment, after polar aligning (with PoleMaster), and usually on Jupiter because it's so bright currently
I've been able to track 4 mins unguided, albeit at shorter focal lengths (550mm).
No idea if this is "good" or not, as I'm still a newb, but I'm happy with the accuracy for now.

Haven't started thinking about autoguiding, but I guess I'll have to when I need to go deeper (and then will likely require more star alignment points?)
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Old 09-11-2020, 03:41 PM
Startrek (Martin)
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Originally Posted by AdamJL View Post
Hi Martin

Are you referring to Star Alignment here?
That's interesting, as I tend to only do 1 star alignment, after polar aligning (with PoleMaster), and usually on Jupiter because it's so bright currently
I've been able to track 4 mins unguided, albeit at shorter focal lengths (550mm).
No idea if this is "good" or not, as I'm still a newb, but I'm happy with the accuracy for now.

Haven't started thinking about autoguiding, but I guess I'll have to when I need to go deeper (and then will likely require more star alignment points?)
Adam,

I was referring to alignment when you use EQMOD and Stellarium to navigate across the night sky , not Star alignment using a Synscan handcontroller etc...
As your using a relatively short focal length system super accurate alignment is not so critical
Not quite sure what you mean by track for 4 minutes unguided ? Tracking on what ? And what frame of reference ?
We usually test out polar alignment on a bright star say magnitude 0.75 to 2.0 and good polar alignment keeps the star stationary in the centre of our reticle for at least 3 to 5 minutes until you see some drift but again this at a certain image scale where the star is “zoomed in “
It all depends if you want to take 30 sec to 60 sec sub exposures ( unguided ) when imaging or from 1 minute to 10 minute sub exposures where guiding is an absolute must
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Old 10-11-2020, 11:26 PM
AdamJL
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Originally Posted by Startrek View Post
Adam,
from 1 minute to 10 minute sub exposures where guiding is an absolute must
Hi Martin

This is the bit that confuses me, because when I shoot, I've been able to hit 4 mins without a guide scope. Short focal length definitely in my favour as you say, but all I do is a polar align and then I frame Jupiter in my DSLR screen and make sure it's centred (there's a cross pattern to help me). Once that's done, I just go to my target and it tracks pretty well.
Mount is a EQ6-R


Quote:
Originally Posted by Startrek View Post
I was referring to alignment when you use EQMOD and Stellarium to navigate across the night sky , not Star alignment using a Synscan handcontroller etc...
Thanks. For Star Alignment I use the SynScan Pro app (haven't yet connected everything to Stellarium or NINA) on my PC... it's the same as the hand-controller, right? That I don't even plug in anymore.

Quote:
Originally Posted by Startrek View Post
Not quite sure what you mean by track for 4 minutes unguided ? Tracking on what ? And what frame of reference ?
Confused again (not hard!)
Tracking on whatever my target is (usually nebula) on my EQ6-R. Not sure what you mean by frame of reference

Quote:
Originally Posted by Startrek View Post
We usually test out polar alignment on a bright star say magnitude 0.75 to 2.0 and good polar alignment keeps the star stationary in the centre of our reticle for at least 3 to 5 minutes until you see some drift but again this at a certain image scale where the star is “zoomed in “
Good tactic, thanks! I'll try it out this weekend if the weather holds.
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