NEQ6 & PDS250 getting failure on 3-Star alignment

[Maddad]

Am new to EQ mounts having previously owned an LX200. Having completed polar alignment, I think, and checked main scope and finder scope are centred on Polaris, I then go for the 3-star alignment having entered Lon, Lat and Altitude. Arcturus is the first star it tries to slew to, but the scope ends up pointing just above the horizon, and about 45’ to the west, way off. I therefore manually slewed it to Arcturus and entered it, then selected Merek and Vega for the next two stars and it found them almost perfectly. However, after the 3rd star, Vega, it then says 3-Star alignment failed. I’m obviously doing something wrong. Can anyone please help a beginner to EQ goto mounts. PS I did do the Alt-Az manual adjustments as part of the polar alignment.

Regards

Perry

Edited July 12, 2020 by Maddad
Missed word

[Jiggy 67]

7 minutes ago, Maddad said:

and checked main scope and finder scope are centred on Polaris,

What do you mean? After polar alignment you shouldn’t have the scope centered on Polaris. Once polar aligned, ensure you return the scope to the home position and commence 1,2 or 3 star alignment. By the way, there’s no need for a 3 star alignment, the 3 rd star is only for correcting cone error, if you’re not worried about that, then the third star serves no purpose 

[jonathan]

When you say you manually slewed it, do you mean with the hand controller or by releasing the clutches / pointing the scope with your hands?  It may be that you must not release the clutches on your scope, and only use the hand controller.  I think some mounts do keep track of manual slewing (by releasing the clutches) but I don't know enough about it to say which mounts do or don't do this.

Edited July 12, 2020 by jonathan

[Maddad]

On 12/07/2020 at 15:41, Jiggy 67 said:

What do you mean? After polar alignment you shouldn’t have the scope centered on Polaris. Once polar aligned, ensure you return the scope to the home position and commence 1,2 or 3 star alignment. By the way, there’s no need for a 3 star alignment, the 3 rd star is only for correcting cone error, if you’re not worried about that, then the third star serves no purpose 

Thanks for response. The manual does not explain what the home position is, so I assumed that after polar alignment, where you have to have the scope to the horizontal to allow the polarscope to see Polaris through the EQ mounted with the counter-weight rod fully retracted, I assumed that you then had to manually turn the scope and align it with Polaris so it all matched up. Obviously this assumption is looking incorrect. What is the home position you set the scope to after Polar alignment then?

 

Thanks for any help you can give a struggling EQ novice. 😉

[Maddad]

23 hours ago, jonathan said:

When you say you manually slewed it, do you mean with the hand controller or by releasing the clutches / pointing the scope with your hands?  It may be that you must not release the clutches on your scope, and only use the hand controller.  I think some mounts do keep track of manual slewing (by releasing the clutches) but I don't know enough about it to say which mounts do or don't do this.

I used the hand controller to slew it to Arcturus. Probably wrong.

[Jiggy 67]

This video will show you the best home position and how to save it. The home position is needed so Synscan knows where it is pointing and starting from. Once you have polar aligned place the scope in the home position. Then do a one or two star alignment. The first star will be off, the better your PA and home position the less so but it will be off. Centre the star with the hand controller as you have done before. 

The second star may also be off, centre it again and you should be good to go. You should receive an “alignment successfull” message. It is useful to use a low power eyepiece, illuminated with a crosshair to center the star accurately 

Some people say you don’t need accurate PA for visual but I think the more accurate it is, the more accurate your GoTo will be. The same applies to the home position and even leveling the mount, these things only take a few minutes so my view is, why not do it right. 

The third star is not required. That is designed to correct cone error which is where the scope is not perpendicular to the dovetail (not level with the dovetail if you know what I mean) . This becomes a problem when crossing the meridian to view an object (not a problem if you keep to the same side of the sky) and will throw the GoTo accuracy out, the third star corrects this and your third star in the alignment process should be on the opposite side of the meridian from your first two. There are ways to check for cone error but I wouldn’t worry about that for now 

[Maddad]

45 minutes ago, Jiggy 67 said:

This video will show you the best home position and how to save it. The home position is needed so Synscan knows where it is pointing and starting from. Once you have polar aligned place the scope in the home position. Then do a one or two star alignment. The first star will be off, the better your PA and home position the less so but it will be off. Centre the star with the hand controller as you have done before. 

The second star may also be off, centre it again and you should be good to go. You should receive an “alignment successfull” message. It is useful to use a low power eyepiece, illuminated with a crosshair to center the star accurately 

Some people say you don’t need accurate PA for visual but I think the more accurate it is, the more accurate your GoTo will be. The same applies to the home position and even leveling the mount, these things only take a few minutes so my view is, why not do it right. 

The third star is not required. That is designed to correct cone error which is where the scope is not perpendicular to the dovetail (not level with the dovetail if you know what I mean) . This becomes a problem when crossing the meridian to view an object (not a problem if you keep to the same side of the sky) and will throw the GoTo accuracy out, the third star corrects this and your third star in the alignment process should be on the opposite side of the meridian from your first two. There are ways to check for cone error but I wouldn’t worry about that for now 

Many, many thanks for that. I think I've missed at least two of the steps, maybe three of them. I've just re-read the manual and cannot find most of the stuff he discusses. I've also bookmarked stages 2, 3, 4 & 5 from his video's. That's me sorted now for the next couple of nights! Again, many thanks.

Maddad (Perry)

[irtuk]

Hey.

Another beginner here, I seem to be having a similar issue with my NEQ6. Having polar aligned the mount and returned the scope to the home position I start two star alignment, the first star it goes for is Arcturus but it's miles off, 20-30 degrees.  Is this normal?

Ed.

[smashing]

On 10/10/2020 at 14:22, irtuk said:

Hey.

Another beginner here, I seem to be having a similar issue with my NEQ6. Having polar aligned the mount and returned the scope to the home position I start two star alignment, the first star it goes for is Arcturus but it's miles off, 20-30 degrees.  Is this normal?

Ed.

Maybe, mine was way off until I made double sure that my BST setting was correct, my time was spot on and made absolutely sure that I had entered the correct date in mm-dd-yyy format and not dd-mm-yyyy.

[irtuk]

Ahha! ok I am pretty sure I have been entering dd-mm-yyyy, I also spotted the daylight saving time thing a couple of days ago, I had to look that up. I always thought daylight saving time was a winter thing which apparently its not. I will go have a try with this now. 

/update/

Yes thats significantly better! It's daylight here, well, ok its overcast and miserable so I am using skymap mounted on a bar to have a guess at what the mount is pointing to, but it was pretty close to its first target, Arcturus, second target was Capella which to be honest I could not find but, still, knowing the right settings to put in the mount is bound to be better from the off.

 

Ed.

 

Edited October 12, 2020 by irtuk