Go Back   IceInSpace > Beginners Start Here > Beginners Talk

Reply
 
Thread Tools Rate Thread
  #1  
Old 08-02-2018, 06:24 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 6,031
Polar alignment for Visual Astronomy

I saw this quick method of polar aligning your mount for visual astronomy, let me know if it will work -

I have a Skywatcher HEQ5 mount

1/ level the mount with boat type bubble level or digital inclinometer like Accumaster Angle guage
2/ use a 600mm long x 50mm wide x 3mm thick aluminium flat bar and fashion a tight square hole one end to fit over the azimuth post or lug in the centre. Centre align the flat bar to north/ south on the tripod base and drill a hole on the opposite side of the mount base through the flat bar and mount base.Secure flat bar to base with nut and bolt
3/ use a good quality compass like a Silva Ranger 3 and sit compass on end of flat bar centre scribed line
4/ move tripod so compass is pointing magnetic south then adjust tripod again to line up with magnetic declination value of viewing site
5/place mount head on tripod and install telescope
6/ balance telescope with counter weights
7/ set latitude of mount using a digital inclinometer
Reply With Quote
  #2  
Old 08-02-2018, 07:11 PM
peter_4059's Avatar
peter_4059 (Peter)
Big Scopes are Cool

peter_4059 is offline
 
Join Date: Jun 2007
Location: SE Tasmania
Posts: 4,532
Yes that will work for visual.
Reply With Quote
  #3  
Old 08-02-2018, 09:35 PM
skysurfer's Avatar
skysurfer
Dark sky rules !

skysurfer is offline
 
Join Date: Dec 2011
Location: 52N 6E (EU)
Posts: 1,152
Try this which is rather similar.

https://www.skysurfer.eu/eqmount.php
Reply With Quote
  #4  
Old 08-02-2018, 11:19 PM
xelasnave's Avatar
xelasnave
Gravity does not Suck

xelasnave is offline
 
Join Date: Mar 2005
Location: Tabulam
Posts: 16,888
You have a camera.
During the day make sure scope via camera points at the same place as polar scope.
At night to align leave scope in home pos and take timed photo to show star trails...the mount is not switched on and stationary...the trails show part of a circle and the center of that circle is CSP.
Adjust mount until the center of the projected circle is in middle of photo.
Its relatively fast and close enough...Thats generally all I do pre astro photos.
Alex
Reply With Quote
  #5  
Old 09-02-2018, 11:43 AM
astroron's Avatar
astroron (Ron)
Supernova Searcher

astroron is offline
 
Join Date: Mar 2005
Location: Cambroon Queensland Australia
Posts: 9,313
4/ move tripod so compass is pointing magnetic south then adjust tripod again to line up with magnetic declination value of viewing site
You should point your scope to True south,Not Magnetic south.
I think the difference is about 11°.
Reply With Quote
  #6  
Old 09-02-2018, 01:15 PM
jenchris's Avatar
jenchris (Jennifer)
Registered User

jenchris is offline
 
Join Date: Nov 2010
Location: Ormeau Gold Coast
Posts: 2,067
Or just use your compass and mark 1 eyeball. It is close enough for visual.
Reply With Quote
  #7  
Old 09-02-2018, 01:32 PM
AstralTraveller's Avatar
AstralTraveller (David)
Registered User

AstralTraveller is offline
 
Join Date: Mar 2008
Location: Wollongong
Posts: 3,766
Quote:
Originally Posted by jenchris View Post
Or just use your compass and mark 1 eyeball. It is close enough for visual.
+1 You only need to be within a couple of degrees of true south.

For elevation I just have the tripod level enough and set the elevation to 34* on the mounts little scale.

For azimuth I use a nice Suunto mirror compass. Look along the RA axis from the north side from about 6-8 steps away using one eye to make sure you are straight behind the axis and then sight up the compass. If the magnetic needle doesn't line up with the guidelines rotate mount to left or right as appropriate. Repeat until it's near enough. That works fine for me.
Reply With Quote
  #8  
Old 09-02-2018, 01:52 PM
astroron's Avatar
astroron (Ron)
Supernova Searcher

astroron is offline
 
Join Date: Mar 2005
Location: Cambroon Queensland Australia
Posts: 9,313
Quote:
Originally Posted by jenchris View Post
Or just use your compass and mark 1 eyeball. It is close enough for visual.
+2 on this one, no need for all that rigmarole.
If you have setting circles, or a go to system then only a reasonably flat piece of ground is all you need to visually observe.

Cheers
Reply With Quote
  #9  
Old 09-02-2018, 02:38 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 6,031
When I set my latitude on the HEQ5 to 35deg using my high quality inclinometer, the mounts scale shows approx 40 deg ( which one has the error of around 4 to 5 degrees )

I tend to trust my digital inclinometer

Has anybody else experienced a similar discrepancy ?
Reply With Quote
  #10  
Old 09-02-2018, 02:44 PM
skysurfer's Avatar
skysurfer
Dark sky rules !

skysurfer is offline
 
Join Date: Dec 2011
Location: 52N 6E (EU)
Posts: 1,152
Quote:
Originally Posted by Startrek View Post
When I set my latitude on the HEQ5 to 35deg using my high quality inclinometer, the mounts scale shows approx 40 deg ( which one has the error of around 4 to 5 degrees )

I tend to trust my digital inclinometer

Has anybody else experienced a similar discrepancy ?
Is this such a device ? This one is very reliable, has 0.1 degree accuracy, much better than a smartphone.
Attached Thumbnails
Click for full-size image (IMG_0437.jpg)
191.9 KB41 views
Reply With Quote
  #11  
Old 09-02-2018, 03:26 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 6,031
My inclinometer is a AccuMaster with accuracy of 0.1deg

I just tried the smartphone, it was out by a few degrees

Sticking with the AccuMaster digital inclinometer

Thanks
Reply With Quote
  #12  
Old 09-02-2018, 06:10 PM
Amaranthus's Avatar
Amaranthus (Barry)
Thylacinus stargazoculus

Amaranthus is offline
 
Join Date: Jan 2014
Location: Judbury, Tasmania
Posts: 1,203
Quote:
Has anybody else experienced a similar discrepancy ?
Absolutely, those printed gradations are for very rough guidance at best.
Reply With Quote
  #13  
Old 09-02-2018, 07:29 PM
Wavytone
Registered User

Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
I'll add:

- replace polar scope with a laser pointer aligned with the polar axis (figure that out in daytime)
- assemble mount and switch on laser
- adjust mount to point at the SCP (use Sky Safari or similar to locate the star field).

First really decent application I've found for a laser pointer.
Reply With Quote
  #14  
Old 09-02-2018, 08:58 PM
raymo
Registered User

raymo is offline
 
Join Date: Sep 2011
Location: margaret river, western australia
Posts: 6,070
I have never heard of the scale on a SW HEQ5 or NEQ6 being more than
a degree or two max. inaccurate. Four or five is IMHO extremely unlikely,
bordering on impossible; you would be able to see the irregularity just by
looking at it after the mount was accurately levelled.
raymo
Reply With Quote
  #15  
Old 09-02-2018, 09:07 PM
Merlin66's Avatar
Merlin66 (Ken)
Registered User

Merlin66 is offline
 
Join Date: Oct 2005
Location: Junortoun Vic
Posts: 8,904
The Accumaster specs quote +/- 0.2 deg accuracy away from the zero points....
https://www.ebay.com.au/itm/NEW-Accu...l-Angle-Gauge-
Reply With Quote
  #16  
Old 12-02-2018, 12:57 PM
ZeroID's Avatar
ZeroID (Brent)
Lost in Space ....

ZeroID is offline
 
Join Date: May 2010
Location: Auckland, NZ
Posts: 4,949
My EQ6 is about 3 deg out on DEC, useless for anything.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 05:01 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement