Polar Alignment

[Neila1975]

Hi all, 

Appreciate some advice on polar alignment.
So far i’ve watched multiple tutorials but have essentially narrowed it down to…

1. Centre reticle
2. Level mount
3. Adjust height angle according to location
4. View Polaris
5. Move Polaris using mount height & left/right adjustments to location on the clock face as per Polar align app

I attempted this yesterday but found after about an hour Polaris had moved inside the reticle 'clock face’ when viewing through the polar scope.
I think i’m right in thinking that this suggests either my reticle isn’t quite centred and/or that I haven’t positioned Polaris quite correctly on the clock face.
It maybe that I’ve the entire process wrong, so any help would be much appreciated.

BTW the mount im using is an HEQ5

Many thanks 
Neil

[Tomatobro]

Three grub screws are used for centring the optics.  In daylight adjust the mount till you can put a distant object on the centre cross then rotate mount to see if object remains centred. Adjust screws till object remains centred.

A distant roof Ariel is a good object to use

[Seelive]

13 minutes ago, Neila1975 said:

Hi all, 

Appreciate some advice on polar alignment.
So far i’ve watched multiple tutorials but have essentially narrowed it down to…

1. Centre reticle
2. Level mount
3. Adjust height angle according to location
4. View Polaris
5. Move Polaris using mount height & left/right adjustments to location on the clock face as per Polar align app

I attempted this yesterday but found after about an hour Polaris had moved inside the reticle 'clock face’ when viewing through the polar scope.
I think i’m right in thinking that this suggests either my reticle isn’t quite centred and/or that I haven’t positioned Polaris quite correctly on the clock face.
It maybe that I’ve the entire process wrong, so any help would be much appreciated.

BTW the mount im using is an HEQ5

Many thanks 
Neil

1. This only needs to be performed once, it can be done in daylight using a distant object as a target (so no need to waste valuable telescope time).

2. The mount doesn't need to be leveled to polar align, but it can help in lessening the amount you need to adjust the azimuth and altitude screws.

5. Ensure that 0 o'clock and 6 o'clock are aligned vertically in the polarscope eyepiece by rotating the RA axis as necessary before setting Polaris to the 'time' given by the handset (or app).

Once polar aligned you will need to reposition the RA axis if necessary to the home position (counterweights vertically downwards) before starting star alignment.

[Neila1975]

36 minutes ago, Tomatobro said:

Three grub screws are used for centring the optics.  In daylight adjust the mount till you can put a distant object on the centre cross then rotate mount to see if object remains centred. Adjust screws till object remains centred.

A distant roof Ariel is a good object to use

Yep, ive attempted this & thought i'd had it centred.

[Neila1975]

38 minutes ago, Seelive said:

1. This only needs to be performed once, it can be done in daylight using a distant object as a target (so no need to waste valuable telescope time).

2. The mount doesn't need to be leveled to polar align, but it can help in lessening the amount you need to adjust the azimuth and altitude screws.

5. Ensure that 0 o'clock and 6 o'clock are aligned vertically in the polarscope eyepiece by rotating the RA axis as necessary before setting Polaris to the 'time' given by the handset (or app).

Once polar aligned you will need to reposition the RA axis if necessary to the home position (counterweights vertically downwards) before starting star alignment.

Thanks - yes should have pointed out I centered (or thought I had) the reticle on Sunday morning.

From what I can see I have followed the correct procedure so something is off, I'm guessing my reticle alignment.

[Tomatobro]

There are so many variables that it is a pure fluke if you get it 100% especially if you set up and take down each session. I have not polar aligned using the polar scope for a few years now but I recall I could never get it spot on.  No harm in having a go though.

 

 

[Jiggy 67]

This might sound daft but are you polar aligning with scope and all accessories mounted including the counter weights. If you’re not then when you mount everything, the mount could move and lose alignment 

Sounds like the mount is moving slightly 

Edited February 2, 2021 by Jiggy 67

[M40]

Hello Neil, try this site for an excellent polar alignment method....  https://darkskies.space/easy-polar-alignment/

It does rely on the tripod being level, the polar scope being aligned and the mount in the home position. 

This is my little routine for setting the home position, you only need to do it the once then mark the mount so you can very quickly set it to the home position. I hope it makes some sort of sense....

Setting Home Position:

1.       Position North tripod leg to face North Celestial Pole (Polaris)

2.       Set and level tripod

3.       Position motor so that the weight bar is at lowest point and pointing to the North

4.       Set the telescope mount so that the telescope locking knobs are to the right

5.       Extend weight bar

6.       Stand facing ON/OFF switch

7.       Release RA clutch lock, rotate body anticlockwise and set body and weight bar to the horizontal position

8.       Level with bubble and lock RA clutch

9.       RA graticule scale is located adjacent to the polar scope cover

10.   Release RA graticule locking screw.

11.   Adjust graticule scale to show 12.00 against marker

12.   Release RA lock

13.   Rotate body clockwise until RA graticule scale shows 6.00 against marker

14.   Lock RA clutch lock

15.   Release DA clutch lock

16.   Rotate telescope mount clockwise so that the telescope locking knobs point down

17.   Level with bubble

18.   Lock DA clutch lock

19.   Declination graticule scale is adjacent to the weight bar

20.   Release the two Declination graticule scale screws and rotate the scale to show zero against marker

21.   Retighten the two DA scale screws

22.   Release DA clutch lock

23.   Rotate telescope mount anticlockwise until the DA scale is at the 90’ position

24.   Lock DA clutch lock

This is the home position.

Telescope should now be in the following position:

North leg pointing towards North Celestial Pole

Weight bar at lowest position and pointing to the North Celestial Pole

When standing facing ON/OFF switch, Telescope mount knobs to the right

RA scale shows 6.00

DA scale shows 90’

 

[Neila1975]

2 hours ago, Tomatobro said:

There are so many variables that it is a pure fluke if you get it 100% especially if you set up and take down each session. I have not polar aligned using the polar scope for a few years now but I recall I could never get it spot on.  No harm in having a go though.

 

 

Yep, totally agree.

[Neila1975]

2 hours ago, Jiggy 67 said:

This might sound daft but are you polar aligning with scope and all accessories mounted including the counter weights. If you’re not then when you mount everything, the mount could move and lose alignment 

Sounds like the mount is moving slightly 

Yes, counter weight, DSLR & lens.  

[Neila1975]

2 hours ago, M40 said:

Hello Neil, try this site for an excellent polar alignment method....  https://darkskies.space/easy-polar-alignment/

It does rely on the tripod being level, the polar scope being aligned and the mount in the home position. 

This is my little routine for setting the home position, you only need to do it the once then mark the mount so you can very quickly set it to the home position. I hope it makes some sort of sense....

Setting Home Position:

1.       Position North tripod leg to face North Celestial Pole (Polaris)

2.       Set and level tripod

3.       Position motor so that the weight bar is at lowest point and pointing to the North

4.       Set the telescope mount so that the telescope locking knobs are to the right

5.       Extend weight bar

6.       Stand facing ON/OFF switch

7.       Release RA clutch lock, rotate body anticlockwise and set body and weight bar to the horizontal position

8.       Level with bubble and lock RA clutch

9.       RA graticule scale is located adjacent to the polar scope cover

10.   Release RA graticule locking screw.

11.   Adjust graticule scale to show 12.00 against marker

12.   Release RA lock

13.   Rotate body clockwise until RA graticule scale shows 6.00 against marker

14.   Lock RA clutch lock

15.   Release DA clutch lock

16.   Rotate telescope mount clockwise so that the telescope locking knobs point down

17.   Level with bubble

18.   Lock DA clutch lock

19.   Declination graticule scale is adjacent to the weight bar

20.   Release the two Declination graticule scale screws and rotate the scale to show zero against marker

21.   Retighten the two DA scale screws

22.   Release DA clutch lock

23.   Rotate telescope mount anticlockwise until the DA scale is at the 90’ position

24.   Lock DA clutch lock

This is the home position.

Telescope should now be in the following position:

North leg pointing towards North Celestial Pole

Weight bar at lowest position and pointing to the North Celestial Pole

When standing facing ON/OFF switch, Telescope mount knobs to the right

RA scale shows 6.00

DA scale shows 90’

 

Thanks  - to be honest Ive haven't bothered to set the home position (is there any need to?), but I have followed the process outlined in my initial post which I understand would be the correct way to polar align, at least I think so.  I also think Tomatobro hit the nail on the head.  In guess it's now a question of what Im prepared to live with.  

[Jiggy 67]

20 minutes ago, Neila1975 said:

to be honest Ive haven't bothered to set the home position (is there any need to?

If you’re using GoTo, an accurate home position is essential, not so much if you’re just tracking 

[Neila1975]

10 minutes ago, Jiggy 67 said:

If you’re using GoTo, an accurate home position is essential, not so much if you’re just tracking 

OK thanks - not quite got that far down the line yet but at some stage no doubt I'll need to

[AstroMuni]

On 02/02/2021 at 14:12, Neila1975 said:

I attempted this yesterday but found after about an hour Polaris had moved inside the reticle 'clock face’ when viewing through the polar scope.

That is expected. Polaris does move around the clock face through the day. As long as its still moving around at the same distance (radius) from centre of reticle then you are good, as the centre is hopefully centred on True North.

[Jiggy 67]

1 hour ago, AstroMuni said:

That is expected. Polaris does move around the clock face through the day. As long as its still moving around at the same distance (radius) from centre of reticle then you are good, as the centre is hopefully centred on True North.

That’s a good point but, if perfectly (which very few will be) aligned Polaris should move around the clock, not inwards as the centre of the polar scope will be bang on the NCP.  More likely to be imperfect pa which would be worse the more imperfect it is. The fact it’s moved so much in an hour makes me think mount instability 

Edited February 3, 2021 by Jiggy 67

[Seelive]

22 hours ago, M40 said:

Hello Neil, try this site for an excellent polar alignment method....  https://darkskies.space/easy-polar-alignment/

It does rely on the tripod being level, the polar scope being aligned and the mount in the home position. 

 

I initially set Polaris on the 0 o'clock graticule line then adjust the RA axis position so that, just using the altitude adjuster, it moves to the 6 o'clock graticule line. Then I set Polaris to the 'time' on the graticule using both the altitude and azimuth adjusters, no need for the mount to be leveled or for the mount to be in the home position but the graticule must (as for any other method) be correctly centered in the polar scope with respect to the rotation of the RA axis but it's actual orientation is irrelevant.

And I know that my SW mount 'spirit level' is nowhere near to being accurate!