Nextstar 8SE Goto problems

[Gryffster]

Hi - I'm a relative newcomer to telescopes with goto - still trying to figure them out.

I have a problem with Goto on the 8SE.

Alignment usually works (Not always, but usually)

I believe my set up is correct - time and date, DST and UTC (It's currently BST in the UK)

I usually use 2-star alignment (Currently, most convenient for me are Sirius and Procyon)

Alignment usually succeeds, but goto just doesn't. The scope slews away, sometimes even to a completely different part of the sky from the selected object (I'm familiar enough with

the sky to be able to identify several bright stars without assistance)

Bizarrely, this happens even if the goto object is one of the alignment stars - how could it possibly not be able to find a star when you've explicitly told it where it is?

I've read that goto sometimes doesn't work well on battery power, so I've aquired a mains adapter. No change.

I haven't yet updated the handset firmware (I'm waiting for a serial-usb adapter.)

Any help would be appreciated.

Thanks

[Oldfort]

I wonder if the problem is that Sirius and Procyon are at similar azimuth at the moment.  Perhaps try Sirius and Regulus.

You don't mention set up for your latitude and longitude.  Sometime mounts come with a default location a very long way from where you are (eg California), and it helps to have these set reasonably close to your actual location, although I think precision is not essential.

[noah4x4]

I assume you are using a Nexstar + HC?

1. It is wise to update Firmware. There have been many bug fixes in recent years including to the pointing model.

2. Try a Sky-Align or Auto Two Star Align.

It's quite easy to incorrectly identify cal-stars - so let the scope do the work. 

The 8SE instruction manual is one of Celestron's better efforts!  I think It is pages 12 & 13 you need.

3.  Have you checked your Location via Menu? This catches out many, especially errors due to not correctly selecting N, S, W, E (e.g. from Equator, Greenwich). 

4. Make sure your mount arm is on the correct side.

5. Make sure you are using the USA date format of mm/dd/yyyy

6. To ensure your calc-star is centre, defocus so you can see a doughnut. Centre that with reference to your eyepiece. It's easier than finding the centre with a tiny point of light.

It is almost odds on that your problem is user data error. The fact you scope heads off in the opposite direction suggests to me your error is highly likely to be either (3) or (5).

 

[Cosmic Geoff]

Your problem is likely to be either user data error, or a poor connection at the power input socket. I have had my Nexstars play up because of poor power plug connctions on a number of occasions. The cure is twofold: use a sharp craft knife to slghtly splay out the split 2.1mm centre pin for a better contact.  And fix a cable tie next to the socket and lead the power cable through it.  This will relieve any strain and twisting at the socket as the mount moves around.

I doubt very much that updating the firmware will cure your problem, even if the mount is old.  You can look up and read the small print that tells you what issues these updates are meant to fix. Does it say anything about the scope heading in the wrong direction?

[JOC]

Lot's of people have goto problems, I sometimes get on the wrong side of folks for suggesting that the Synscan Init 2.0 app for Skywatcher systems might be useful even for non Skywatcher systems, but most of these systems do have similar data input needs and the app. does normally give all the values in the correct format.  I last contributed the information to the thread linked to below and you might find that reading through to the end of the thread and the final problem/solution that the OP had is informative.  Such things as East and West, and leading zero's and the correct format of the Lats and Longs are really important and so easily missed.

 

 

[Wyvernp]

15 hours ago, noah4x4 said:

5. Make sure you are using the USA date format of mm/dd/yyyy

 

This got me so many times with my 8se...

[Ledge1962]

I had a similar problem to this on a Sky-watcher 250P.  It would align perfectly, then once I tried to Goto a target, it would head of in all sorts of directions, usually bottoming out on the mount.

I went into the handset, and in the Utility Func menu, - Show Position, the ALT coordinates did not update when moving the scope up and down. It turned out the Alt Encoder was broken. I hope this isn't your problem, but it is worth checking it to rule it out.

 

 

[jonathan]

I had power connection problems with my 8SE mount, I eventually ended up replacing the power socket with a BNC connection which was very effective and solved the random resets completely.  However, I'd already outgrown the mount with my additions to the 8SE OTA (focuser, 2" diagonal, 9x50 finder, among others) so replaced it with an NEQ6 Pro SynTrek - it might be overkill but it's rock steady even under windy conditions!  No Goto, can't say that I really miss it after all the problems it gave me.  HEQ5 Pro would no doubt be enough for the 8SE, can be upgraded to Goto.

Edited May 10, 2020 by jonathan

[Erling G-P]

56 minutes ago, jonathan said:

I had power connection problems with my 8SE mount, I eventually ended up replacing the power socket with a BNC connection which was very effective and solved the random resets completely.  However, I'd already outgrown the mount with my additions to the 8SE OTA (focuser, 2" diagonal, 9x50 finder, among others) so replaced it with an NEQ6 Pro SynTrek - it might be overkill but it's rock steady even under windy conditions!  No Goto, can't say that I really miss it after all the problems it gave me.  HEQ5 Pro would no doubt be enough for the 8SE, can be upgraded to Goto.

HEQ5 Pro is a goto mount - no upgrade needed (if bought new at least; don't know if older versions were without goto)

[John]

The very early HEQ5 mounts did not have GOTO. They are black rather than white. Then a GOTO upgrade came out which was popular. Then the GOTO version of the HEQ5 cam out and the non-GOTO version was dropped. It was at that point that the colour scheme changed to white. There used to be 2 versions of the HEQ5 GOTO, one with a basic handset (Syntrek) and one with the fully featured one (Synscan). I think the Syntrek version has been dropped now.

 

[jonathan]

On 10/05/2020 at 12:22, John said:

The very early HEQ5 mounts did not have GOTO. They are black rather than white. Then a GOTO upgrade came out which was popular. Then the GOTO version of the HEQ5 cam out and the non-GOTO version was dropped. It was at that point that the colour scheme changed to white. There used to be 2 versions of the HEQ5 GOTO, one with a basic handset (Syntrek) and one with the fully featured one (Synscan). I think the Syntrek version has been dropped now.

 

That would explain why I can't see the Syntrek version of my NEQ6 Pro mount for sale (new) anymore, it was the same thing with two versions available, the only difference being the handset and about £300.  I like the Syntrek, it's simple and doesn't require any handset setup from one session to the next.

Edited May 13, 2020 by jonathan