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question re. my 8se and the SkySync I just got...

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#1 bluenote

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Posted 29 September 2013 - 11:01 AM

I have had problems with Star alignment since I got my 8SE.
So I got a SkySync hoping that might help...My question is: Once I have the SkySync up and running, GPS on etc., Do I still need to do a 3 or 2 star alignment to get the damn thing to do what it is supposed to? :confused:

#2 philippe44

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Posted 29 September 2013 - 12:43 PM

When did you buy that scope ? Are you sure this is alignment problem or is this goto problem ? I happened to have similar issues and it was due to a faulty motor assembly - See this thread and tell me if you experience the same problem. You should do the test of moving the mount vertical to horizontal and also do a full rotation and see what you read on the HC

#3 bluenote

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Posted 30 September 2013 - 09:23 PM

Thanks for your reply Philippe...Im not sure if it is an alignment or a go to problem.
I will try your recommendations..Im getting very frustrated with the whole thing. Its a p.i.a.

#4 philippe44

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Posted 30 September 2013 - 09:28 PM

I mean is the alignment successful but the goto fails or is the alignment failing ? The Get Alt/Azm reading is in the Utility menu

#5 Midnight Dan

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Posted 01 October 2013 - 06:05 AM

Hi bluenote:

Can you provide details about what you're doing and what the results are? We've had pretty good luck on this forum with helping people that are having alignment problems. Usually it's a simple change in procedure, but sometimes it indicates an underlying malfunction like in Philippe's case.

-Dan

#6 Bob Griffiths

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Posted 01 October 2013 - 07:21 AM

Yea I'm with Dan on this ...its pretty uncommon to have alignment problems IF you use the correct procedures ...

Give us a detailed step by step write up of how you align the scope...,.

Not saying its not a firmware or mechanical problem but I seriously doubt it

The GPS does not do a darn thing to help you do an alignment EXCEPT enter the location date and time...

Bob G

#7 bluenote

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Posted 01 October 2013 - 09:16 PM

Thanks for the support guys..I do the alignment exactly as stated in the owners manual and seem to get 'alignment failed' every time. I was hoping that the Sky Sync would solve the problem but no such luck. My next step I think I should take is to find someone who has an 8SE and have them see if they can align mine...that would rule out some inherent bug in my scope.

#8 hamdul

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Posted 01 October 2013 - 10:25 PM

The owners manual states several different methods of alignment. Which do you do? When I first used "Sky align" quite often I would get "Alignment Failed" , But since using the "Auto 2 Star Alignment" I've never gotten that message. So tell us, What exactly do you do? Saying following the manual doesn't cut it. :question:
Also, when approaching the alignment stars do you approach "Up & Right"
Fred

#9 bluenote

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Posted 02 October 2013 - 06:55 PM

Hi Chaps....I have been using the 2 star alignment . But I just found out from Celestron today that they now have the 'Starsense' which is a relatively new accessory that does what I thought the Sky Sync would do, it aligns your scope within 2-3 minutes and you are ready to start observing. This is what I wanted from the get go, plug it in and have the scope set up for you automatically. Its worth it to me to not have to dick around trying to get up and running, especially now its getting colder. Once again,I thank everyone for their help.

#10 Tel

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Posted 03 October 2013 - 03:07 AM

Hi Bluenote,

I can't help thinking that you're going to regret this purchase if the problem lies, as it is most likely to lie, in the possibility that your 'scope is not initially set up correctly. If this is the case, no "bolt-on goodie" is going to magically effect a cure.

Perhaps take a look at this thread, (below), before you act, and, in particular, at the 19th posting down. It will at least provide you with a basic but very necessary "check-list" on what you need to have done primarily, in order (hopefully) to achieve good Auto Two Alignment results.

Remember, that your 'scope was designed to work as supplied and not only as a result of "extras" peddled by the manufacturer.

http://www.cloudynig...5417848/page...

Best regards,
Tel

#11 Midnight Dan

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Posted 03 October 2013 - 06:25 AM

As regards the Skysync accessory, I agree with Tel. However, the StarSense accessory should do what you want by automating the entire startup/alignment process ... assuming there is no problem with your mount.

-Dan

#12 hamdul

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Posted 03 October 2013 - 08:33 AM

Hi Bluenote
I agree with Tel (He is the voice of reason)
When I had start up problems he posted the following. As you can see there is more here than what the manual tells you.

Both Francois and Mark have provided excellent suggestions and tips on how to improve the GoTo accuracy of your Nexstar 8SE. For my part, I'm not exactly sure what I can add in these terms so perhaps the best I can do is take you through the whole setting-up and follow-up procedures which I (personally) find, works extremely well for me.

Before starting, you need to balance your 'scope tube away from the mount.

Having therefore placed all accessories, (finder, diagonal, eyepiece etc.) on the tube, rest it on a pencil on a flat, (table top), surface and find the point at which it balances. Mark the point and replace the tube on the mount arm so that there is a little fore-end weight bias.

Now with your 'scope switched on, select "Menu" and then "Scope Set-Up". Press "Enter" and then, by toggling either the 6 or 9 button, find "GoTo Approach".

Press "Enter" to find the "Azm Approach" which must be set to POSITIVE. Then similarly, find the "Alt. Approach" Approach". This might be set to NEGATIVE, the default setting. If it is not on default, set it so. You can always change it following experimentation at a later date. The purpose of this exercise is to get you up and running NOW !

As already mentioned, you now need to ensure that your antibacklash settings are optimised for both the altitude and azimuth axes.

To achieve this, (and the operation can be carried out in broad daylight),keep you 'scope loaded with all usual accessories, (finder, diagonal, eyepiece etc.), level it and, as Venus is currently available in the daytime sky, perform a "Solar System Align" on this planet.

Note there is no need to seek it out, you are merely trying to achieve "Align Success" on the screen of your hand controller. This will ensure the 'scope is tracking which is necessary to antibacklash adjustment.

Thus just point your 'scope to approximately where you think Venus to be at the (daytime) time and date you have entered, press "Enter" and "Align" buttons and your 'scope will be tracking thereafter.

Now slew your 'scope around and focus it on a distant brick wall or a tiled (shingled) roof. The idea behind using a brick wall or tiled area of a roof is to provide an improvised grid pattern on which to work.

Now select "Menu" and by means of pressing either the 6 or 9 button, select "Scope Set-Up". Press "Enter" once again and use the 6 or 9 to toggle to "Antibacklash". Press "Enter" once again.

Let's assume that "Azm. Positive" appears on your hand controller's screen.

Press "Enter". A figure between 0-99 will be seen on your screen.


Set your slew rate to 3 or 4 and then move your scope HORIZONTALLY ONLY across the brick or tiled grid pattern noting how long it takes before the 'scope begins to move, whether the movement is at all jerky in its action and whether, when you have traversed the grid by a reasonable distance, the motion stops when you take your finger off the direction button.

Move the 'scope several times back and forth across the grid in order to get a "feel" for what how it responds. If the drive take up is exceptionally slow, (and allow a few seconds here and there), or the motion is jerky either on drive take up or on stopping, adjust the shown figure in say, increments of 5.

When you are satisfied that you have a smooth action, that there is no great delay in drive take-up and that your 'scope stops when you take your finger from the direction button, then "Enter" the figure you have chosen and move to "Azm. Negative", repeating the exercise once more.

You should have now set both the Azm. Positive and Negative antibacklash.

Now move to adjusting the Alt. Positive and Negative antibacklash in exactly the same way but this time, moving the 'scope tube ONLY UP and DOWN. You will however probably find that the vertical (altitude) axis is much more sensitive in its response to adjustment of the Positive and Negative figures.

The above should now put you in a position to make accurate alignments.

ALIGNMENT:

Choose the "Auto Two Star" method. (This method appears by concensus, to be the most reliable).

Thus with your 'scope tube pointing North and with the mount arm on your left as you stand behind the instrument. Switch on your 'scope and enter all relevant data, Time, Date etc. (I assume from your previous posts that you are acquainted with the procedure and the necessity for the relevant accuracy here).

Irrespective of what your hand controller offers, choose Polaris as your first star. (I make the assumption that you can see it). If it is not the first star on offer, you will need to toggle either the 6 or 9 buttons to produce it on screen.

Now locate it in your finder and, having done so, press "Enter". You should now see it in your eyepiece, (a 25mm will be quite sufficient), although it may not be in focus.

Keep it defocused as I think Francois suggested, so that it looks rather like a large doughnut. This shape allows you to centralise it in your eyepiece far more easily since your eye is very susceptible to the concentricity of rings.

Thus, by comparing the position of the doughnut with the edge of the field of view, you should be able to centre it very accurately.

However, the doughnut may not be in the the centre to start with. No matter ! Using the direction buttons on the hand controller, move it to the bottom left quadrant of your eyepiece.

Now from this position, move it right and upward to centralise. If you overshoot, take it back to the bottom left quadrant and begin again. When you are satisfied that you have it centralised it, press "Align" and you will be offered your second alignment star.

This star should be between 30 and 70 degrees in altitude and at least 90 degrees from your first choice; Polaris.

Let's assume it has chosen or that you have chosen Altair.

Press "Enter" and your 'scope will automatically slew to this star. If it "lands" nowhere in the vicinity of Altair you will know immediately that something is wrong, but all being well it should be near. Now merely go through the same procedure as you did when aligning Polaris and you should have a good alignment.

Note that your 'scope will be now tracking in sidereal time and that the "Cordwrap" feature will now be "On" by default. (I choose to operate with it "Off" but I leave that to you. If you leave it "On", you may need to set a "No Cross Line").

Now for the GoTo and tracking performance of your 'scope.

If your alignment has been successful, any object you "GoTo" should be within the field of view of a 25mm eyepiece although not necessarily in its centre. Thus if you wish to bring it to centre, (as is normal), use the same movement (bottom left to the right and up) as used when you aligned, to do so.

There is a caveat however:

This procedure should keep your 'scope tracking well when operating between North and South through East but you may find that objects may begin to slip from the field of view in very short time when operating the 'scope between South and North through West. If this occurs, simply align or realign the "slipping" object by placing it in the UPPER left quadrant of the eyepiece and recentralising it by moving it to the right and DOWN.

I have attached the paper describing this method and its effects to this post which I hope will help you further.

Hoping though that this helps overall,

Best regards,
Tel

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Truth is the cubed root of Verbosity.

#13 bluenote

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Posted 03 October 2013 - 11:28 PM

Again, thanks to everyone for their input here. Hamdul, I will follow your instructions to the 't' this Sat. at my astronomy society star party (on a mountain top here in No. California) and see if that solves the problem. I do agree with Tel that if the problem I have been having is caused by the mount then no accessory out there will fix it. Will report back with results next week

#14 Tel

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Posted 04 October 2013 - 04:29 AM

Hi Bluenote,

Well, I may be wrong in my analysis but to reiterate, I really don't think this problem can or will be solved through the use of "Starsense".

Unless there is something mechanically or electrically/electronically fundamentally adrift within your 'scope, as was the case with Philippe's, (which of course "Starsense" and its like would not have remedied either), then there should be no reason why your 8SE should not function if all the basic set-up requirements have been implemented correctly.

Going to your star party at the weekend should give you a golden opportunity to check out, make, and perhaps correct these basic settings, perhaps with the help of another society colleague. (?) :idea:

All success for the weekend and please keep us posted as to the outcome.

Best regards,
Tel

#15 hamdul

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Posted 04 October 2013 - 08:11 AM

Bluenote,
I wish I could take the credit for those instructions BUT (Isn't there always a BUT) They really are instructions from our Guru Tel, :bow: :bow: who sent them to me when I was in your shoes. :bawling:

Fred

#16 bluenote

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Posted 06 October 2013 - 10:05 PM

Success! After following Tel's instructions carefully, I was amazed to see
'Alignment successful' on the hand control...I think what clenched the deal was using Polaris as my first alignment star and then going to Altair (I think it was Altair) for my second alignment...anyway right after I got the 'successful alignment' confirmation my scope was up and running like a champ. Great team effort chaps, drinks all round.

#17 hamdul

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Posted 06 October 2013 - 10:36 PM

Bluenote

Just think of all the money you saved. Now you can buy some accessories. :jump:

Fred

#18 Tel

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Posted 07 October 2013 - 02:03 AM

Good to hear, Bluenote.

Happy future viewing !

Best regards,
Tel






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