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Alignment Problelm__go to off target

Celestron
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#1 ToKepler

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Posted 21 March 2018 - 12:32 PM

I'm a Newbie to Telescopes. My 7-year got a hand-me down Celestron 130SLT. I read through the manual and got it all lined up. The problem has been that it doesn't stay with the object being observed, the moon for instance. Within a minute falls our of view. From there I have to continually adjust it with the up-and-down-sideway arrows on the controller. This, of course throws the whole alignment out of sync and we are done for the night.--As there's no chance of slewing to a second object.

On a separate feed, Michael Swanson recommended I look at my power source. Michael has laboriously done the "leg work" on all things Celestron it appears. On the following link he game  http://www.nexstarsi...owerSources.htm he recommends a 12v-5amp (min) set up. Well, well... the power supply I got from Celestron has an output of 2.amps. That's not even half of the amps recommended--And this is where I am. Now I need to come up with the right power source. So if anyone is experiencing issues as I described please look at your power source set up. Why Celestron sells the half-baked power source beats me. Be that as it may, I am glad to be on the right track at solving this problem, with Michael's handy-dandy advise I shall "save the day" for my 7-year old and share on father-son wonderment of the celestial for years to come.  I'll shall update my findings next.  And Thank you Michael Swanson.



#2 jakecru

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Posted 21 March 2018 - 12:35 PM

Are the altitude and azimuth clutches tightened? Is the mount level? These would be the first two things I would check. Hopefully someone else could help out more! 



#3 ishorx

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Posted 21 March 2018 - 01:09 PM

hi,do you do a polar alignment also,depending on how close you are to the pole will determine how much drift your getting,the 2 amp power should be okay as recommended by celestron.



#4 theastroimager

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Posted 21 March 2018 - 01:55 PM

Celestron sells a half-backed power supply for the same reason that Meade does...maximize profits.

 

My 12" LX200 won't even initialize properly at any temperature much below freezing using the Meade supply.

 

I now use a 30 amp power supply made for amateur radio. More than enough power to run the 'scope, dew heaters, camera and even an electric deadlock detangler :-)



#5 mclewis1

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Posted 21 March 2018 - 01:57 PM

Mike's recommendation of a 5 amp power supply is a good all round suggestion. More amperage just ensures extra insurance when running and the price difference between a 5 and a 2 amp model is minuscule.

 

A 2 amp power supply will also be fine for an SLT but you probably don't want to go down to a 1 amp model.

 

With the mount working properly using the direction arrows on the hand controller does not ruin the alignment, you can slew around with the direction arrows all you want and then do a goto an object and expect the same accuracy as before.

 

Clearly there's an issue somewhere with your SLT. It also sounds to me like one of the axis connections are loose. To adjust these you'll have to get inside the mount. Normally you'll just be tightening up a large bolt just a little bit. You'll also need to roughly balance the tube, it should not be putting a lot of pressure in one direction on the altitude axis.

 

As a hand me down scope I would also do a Factory Setting reset of the hand controller and then re enter the user data including the DST and Time zone settings.

 

Once all that is taken care of and the finder scope is aligned with the primary scope you can do your initial alignments again. Choose well separated stars and center them using only up/right motions for the final centering movements.



#6 GoFish

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Posted 21 March 2018 - 02:12 PM

I did not see where you described the alignment procedure you used.  Perhaps there is something sinister lurking there smile.gif

 

Also, there is backlash in this mount (and really all mounts to a degree).  This exhibits itself in many ways. 

 

One of the things that backlash can do is create a time lag between when the mount is done slewing to the target (say the moon), and when tracking actually seems to start.  An object can drift a ways during this time lag and give the impression that tracking isn't working. 

 

So it may be the case that the moon would drift for a while until the backlash is cleared, and then tracking will engage and keep up with the moon's movements.  You would need to slew the scope a little bit manually with the hand control buttons to recenter it initially, however.

 

(It would be easier for me to read your posts if the font were larger.  Just sayin').



#7 RMannix57

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Posted 21 March 2018 - 02:56 PM

There are different tracking modes for stars, moon, and planets. Set the tracking mode to "Lunar" 



#8 mclewis1

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Posted 21 March 2018 - 07:59 PM

Use lunar tracking rate if you are spending a lot of time at high magnifications studying individual lunar features but in general it's not necessary. The difference in the rates usually isn't enough to worry about for most.



#9 Bean614

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Posted 21 March 2018 - 08:48 PM

"do you do a polar alignment"...???????  Does everyone here actually understand that the OP's SLT is an Alt/Az Go-To Mount, and does NOT require Polar Alignment???

 

   And this: "Are the altitude and azimuth clutches tightened?"....???????

WHAT Clutches????????

 

Again, I will never understand why anyone, not intimately familiar with the item being discussed, would post ANY statement about it, no matter how well intentioned.  For new members, especially, this can be very, very confusing, and do more harm than good.


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#10 Michael_Swanson

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Posted 21 March 2018 - 09:42 PM

I'm a Newbie to Telescopes. My 7-year got a hand-me down Celestron 130SLT. I read through the manual and got it all lined up. The problem has been that it doesn't stay with the object being observed, the moon for instance. Within a minute falls our of view. From there I have to continually adjust it with the up-and-down-sideway arrows on the controller. This, of course throws the whole alignment out of sync and we are done for the night.--As there's no chance of slewing to a second object.

On a separate feed, Michael Swanson recommended I look at my power source. Michael has laboriously done the "leg work" on all things Celestron it appears. On the following link he game  http://www.nexstarsi...owerSources.htm he recommends a 12v-5amp (min) set up. Well, well... the power supply I got from Celestron has an output of 2.amps. That's not even half of the amps recommended--And this is where I am. Now I need to come up with the right power source. So if anyone is experiencing issues as I described please look at your power source set up. Why Celestron sells the half-baked power source beats me. Be that as it may, I am glad to be on the right track at solving this problem, with Michael's handy-dandy advise I shall "save the day" for my 7-year old and share on father-son wonderment of the celestial for years to come.  I'll shall update my findings next.  And Thank you Michael Swanson.

Hi ToKepler,

 

In that article at my website I recommend a minimum of 1.5 amp for the smaller NexStars like your SLT.  As long as the Celestron power supply is functioning properly, it will work fine for your scope.

 

Manually slewing with the arrow buttons does not cause any problem with later GoTo operations.  The mount keeps track of where it is pointed even when you manually slew.

 

GoFish's post about backlash is a likely cause of the momentary drift you are experiencing.  Here is an article at my website describing one method to adjust the anti-backlash settings:

http://www.nexstarsi...ds/Backlash.htm

 

But...we need to know more details about how you are aligning the scope (pointed at 3 stars, got "alignment successful" message or ???).

 

Best regards,
Mike Swanson
Author of "The NexStar Users Guide II"
Author of "The NexStar Users Guide"
Author of "NexStar Observer List"
http://www.nexstarsite.com


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#11 Jim4321

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Posted 22 March 2018 - 04:55 AM

I'd also suggest first going back to the beginning and being sure all the basic data you've entered in the hand controller is correct.  Lat & long (or city), time, daylight vs standard time, etc.  Be sure your tripod is close to level, especially if using a single object alignment.  Until you get the hang of it, center alignment targets by using a longer eyepiece followed by a shorter; de-focusing to enlarge your target also helps with centering. 

 

Good luck with it!

 

Jim H.




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