Go-to alignment help

[dc22957]

I’ve purchased a National Geographic/Bresser 90mm go-to telescope after reading a good review for it from Sky at Night and I’m having a little trouble with the alignment.

It goes to the right area of the sky but the star is always slightly to the left and the controller only allows you to fine tune by going up and down, not sure to side and it says not to move the telescope in any other way without confusing it. Any suggestions?

 

 

[Sabalias]

Hi there,

I'm not familiar with that scope so I'm afraid I can't comment on the functionality; however, my immediate thought is that the polar alignment might be slightly off? Of course, that assumes that polar alignment is required in the first place.

Stu

Edited June 10, 2021 by Sabalias

[dc22957]

I don’t believe it has polar alignment. You simply have the tube level facing north, enter your location and select one, two or three star alignment. 

[Sabalias]

Just now, dc22957 said:

I don’t believe it has polar alignment. You simply have the tube level facing north, enter your location and select one, two or three star alignment. 

This may sound like a silly question, but how are you finding north? Does the scope require magnetic or true? The only other thing I can think of is that the latitude may be off by a small amount....

[Alan64]

The review...

https://www.skyatnightmagazine.com/reviews/telescopes/national-geographic-90mm-automatic-telescope/

Specs, manual and user-reviews... 

https://www.bresser.de/en/Junior/NATIONAL-GEOGRAPHIC-Automatic-Telescope-90-mm.html

Make certain that the Daylight Savings Time entry is correct.

You don't want to use AA-batteries to power the mount.  It uses six, and for a total of 9V.  Use the AC adaptor if you have one, or get one if you don't.  You can also connect a 12V lithium-ion battery-pack or power-tank.  You'll need to research that...

Best wishes for your success.

Edited June 10, 2021 by Alan64

[Sabalias]

Ah yes, daylight saving. I'd forgotten that.

Stu

[dc22957]

51 minutes ago, Sabalias said:

This may sound like a silly question, but how are you finding north? Does the scope require magnetic or true? The only other thing I can think of is that the latitude may be off by a small amount....

You slot a compass into the eyepiece slot and the compass has a bubble so you know when it is level.

[dc22957]

52 minutes ago, Alan64 said:

The review...

https://www.skyatnightmagazine.com/reviews/telescopes/national-geographic-90mm-automatic-telescope/

Specs, manual and user-reviews... 

https://www.bresser.de/en/Junior/NATIONAL-GEOGRAPHIC-Automatic-Telescope-90-mm.html

Make certain that the Daylight Savings Time entry is correct.

You don't want to use AA-batteries to power the mount.  It uses six, and for a total of 9V.  Use the AC adaptor if you have one, or get one if you don't.  You can also connect a 12V lithium-ion battery-pack or power-tank.  You'll need to research that...

Best wishes for your success.

I’m using AA’s for now but will get a plug. The main problem is that once it has found the star it says to centre it in the field of view, but it only allows you to go up or down whereas for me the star, in this case Vega, is to the left of the scope out of field of view.

[Alan64]

49 minutes ago, dc22957 said:

I’m using AA’s for now but will get a plug. The main problem is that once it has found the star it says to centre it in the field of view, but it only allows you to go up or down whereas for me the star, in this case Vega, is to the left of the scope out of field of view.

Hmm, I'm seeing that there are four directional keys on the hand-controller.  But your controller's screen is telling you only up or down?  If so, that doesn't make sense.  You should be able to go up and down, and left to right with those keys.  It may be the AA batteries causing that glitch.  Also, are you having this problem when performing a one-star, two-star, or three-star alignment?

Do research about using a lithium-ion power pack, as it will power the mount for a long time without a hiccough.  For example...

https://www.amazon.co.uk/TalentCell-Rechargeable-11000mAh-20000mAh-Portable/dp/B06Y5G3C8Z/ref=sr_1_6?crid=14PBWBFSJF761&dchild=1&keywords=lithium+ion+battery+12v&qid=1623325074&sprefix=litium+ion+battery+%2Caps%2C302&sr=8-6

That one can be attached to the mount with Velcro®.  You do want to get the polarities, +/-,  correct at the C12V connection at the mount-head, whether you use an external battery source or the AC adaptor.

Edited June 10, 2021 by Alan64

[dc22957]

38 minutes ago, Alan64 said:

Hmm, I'm seeing that there are four directional keys on the hand-controller.  But your controller's screen is telling you only up or down?  If so, that doesn't make sense.  You should be able to go up and down, and left to right with those keys.  It may be the AA batteries causing that glitch.  Also, are you having this problem when performing a one-star, two-star, or three-star alignment?

Do research about using a lithium-ion power pack, as it will power the mount for a long time without a hiccough.  For example...

https://www.amazon.co.uk/TalentCell-Rechargeable-11000mAh-20000mAh-Portable/dp/B06Y5G3C8Z/ref=sr_1_6?crid=14PBWBFSJF761&dchild=1&keywords=lithium+ion+battery+12v&qid=1623325074&sprefix=litium+ion+battery+%2Caps%2C302&sr=8-6

That one can be attached to the mount with Velcro®.  You do want to get the polarities, +/-,  correct at the C12V connection at the mount-head, whether you use an external battery source or the AC adaptor.

The left and right arrows seem to be to scroll through menus and when entering date and location. Batteries seem fine as when it is automatically slewing it has no problem.

[Alan64]

1 minute ago, dc22957 said:

The left and right arrows seem to be to scroll through menus and when entering date and location. Batteries seem fine as when it is automatically slewing it has no problem.

But when you're trying to center a star during the alignment procedure, you must be able to go left to right.  There's something amiss there.  You should also be able to slew left to right, as when moving from one part of the sky to the other.

[dc22957]

2 minutes ago, Alan64 said:

But when you're trying to center a star during the alignment procedure, you must be able to go left to right.  There's something amiss there.  You should also be able to slew left to right, as when moving from one part of the sky to the other.

So you can move manually left and right and up and down but not if using the goto. The arrows only work when aligning, and again only up and down very very finely to centre the star, other than that you have to select an object for it to find.

[dc22957]

5 minutes ago, Alan64 said:

But when you're trying to center a star during the alignment procedure, you must be able to go left to right.  There's something amiss there.  You should also be able to slew left to right, as when moving from one part of the sky to the other.

It does slew left and right when it is moving to a target but you can not move it left and right with the controller yourself in bless manually with hands if unlocked but it says that will mess with alignment.

 

you see my problem!

[Swoop1]

Could it be the slewing rate that is set?

I had this problem with my SW HEQ5Pro until I sussed out how to change the manual slew rate (press the rate button until Rate 2* show (where 2 represents the current rate) then press another number up to 9 to increase or decrease the slewing speed). RA would slew perceptibly but Dec wouldn't. Adjusted the rate and all was good.

[dc22957]

5 minutes ago, Swoop1 said:

Could it be the slewing rate that is set?

I had this problem with my SW HEQ5Pro until I sussed out how to change the manual slew rate (press the rate button until Rate 2* show (where 2 represents the current rate) then press another number up to 9 to increase or decrease the slewing speed). RA would slew perceptibly but Dec wouldn't. Adjusted the rate and all was good.

It allows you to change rate but it has options called star speed and moon speed. You can go to custom but it says “star speed +0100”

[iapa]

I think the option you are looking at is Setup | Tracking Rate.

Try Setup | Telescope Settings menus? You are looking for Slew Rate.

At @Swoop1 says, slew rate may be slow when manually going “left/right”.

 

Edited June 10, 2021 by iapa

[Alan64]

Page 12 and 13 of the manual details the alignment procedures quite clearly.

54 minutes ago, dc22957 said:

It does slew left and right when it is moving to a target but you can not move it left and right with the controller yourself in bless manually with hands if unlocked but it says that will mess with alignment.

 

you see my problem!

It could be that the left/right buttons on the controller are worn out; wonky.  Was this a previously used kit when you purchased it?

Edited June 10, 2021 by Alan64

[dc22957]

19 minutes ago, Alan64 said:

Page 12 and 13 of the manual details the alignment procedures quite clearly.

It could be that the left/right buttons on the controller are worn out; wonky.  Was this a previously used kit when you purchased it?

Yes however was marked as opened but never used. Handset still has sticker protecting the screen.

Edited June 10, 2021 by dc22957

[Alan64]

It could have been a return, and with the controller being defective from the factory.  It wouldn't be the first time that that has happened.  If you can't return the kit, or if it's out of warranty, you can take the controller apart and attempt a repair; cleaning underneath the buttons, for example.

[Alan64]

Incidentally, I had a relative who never removed the clear, protective covers from their electronics, and no matter how old the item was.  They considered it sacrilege to do so, even.

 

[dc22957]

37 minutes ago, Alan64 said:

Incidentally, I had a relative who never removed the clear, protective covers from their electronics, and no matter how old the item was.  They considered it sacrilege to do so, even.

 

Luckily it’s all sorted now. Turns out (not in the manual) that if you press 1-9 on the keypad at any point, not a particular menu, that changes the speed. It was on speed 1 which means almost impossible to the eye movement.

[iapa]

Great news.

@Swoop1 good call on that.

[Alan64]

All's well that ends well.