Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Mounts

Pages: 1 | 2 | (show all)
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Can't accurately star align CG5-GT new [Re: magnus]
      #3823396 - 05/23/10 09:31 AM

Quote:

Rod!
Thanks for your advice: "Are you doing the final centering with up and rights buttons only?"
I had missed that detail and at last my 8"f/6 Newt find it`s targets on my CG-5GT. Had just given up hope that my Newt could work on the CG-5GT but now it sure does!

All the best,
Magnus




The up/right bidness is Celestron's way of taking backlash into account--like Meade's Drive Training. You wouldn't think it could make much difference...but...yeah, it sure does.


Post Extras: Print Post   Remind Me!   Notify Moderator  
seeker372011
scholastic sledgehammer


Reged: 03/05/04

Loc: Sydney , Australia
Re: Can't accurately star align CG5-GT new [Re: rmollise]
      #3827396 - 05/25/10 06:50 AM

Quote:

Quote:

Rod!
Thanks for your advice: "Are you doing the final centering with up and rights buttons only?"
I had missed that detail and at last my 8"f/6 Newt find it`s targets on my CG-5GT. Had just given up hope that my Newt could work on the CG-5GT but now it sure does!

All the best,
Magnus




The up/right bidness is Celestron's way of taking backlash into account--like Meade's Drive Training. You wouldn't think it could make much difference...but...yeah, it sure does.



yes it is incredibly important-I found that you cant autoguide well unless you follow this mantra

it eventually becomes second nature-I find myself doing it even on my EQ6 now


Post Extras: Print Post   Remind Me!   Notify Moderator  
xcy
sage


Reged: 05/15/06

Loc: Europe
Re: Can't accurately star align CG5-GT new [Re: seeker372011]
      #3841829 - 06/01/10 11:27 PM

What is the correct procedure to add new alignment and calibration stars in case I chooce the wrong ones without having to power off and on the mount again?

Post Extras: Print Post   Remind Me!   Notify Moderator  
Chris Rowland
professor emeritus


Reged: 02/28/05

Re: Can't accurately star align CG5-GT new [Re: xcy]
      #3842055 - 06/02/10 03:58 AM

Select a star you wish to use.
Press the align button
Select Replace Alignment Stars or Replace Calib Stars
Follow the instructions on the screen.

It's more or less like that, this is from memory.

Chris


Post Extras: Print Post   Remind Me!   Notify Moderator  
Terrance
professor emeritus


Reged: 08/11/04

Loc: Near Portland Or.
Re: Can't accurately star align CG5-GT new [Re: Chris Rowland]
      #3843729 - 06/02/10 10:55 PM

You select the star you want to use for a replacement, and send the scope there. then return to the top of the menu, and press the align button. If you want to replace an alignment star hit alignment stars, and you will be given an option to "replace..." with the star you selected, and then you simply center and hit enter. If you want to replace a Calibration star, select "calibration stars" instead of alignment stars, and do the same thing.

Note I have had bad luck "replacing" a solar system alignment that stared with either the moon or sun, but no difficulty with replacing a solar system alignment that began with a planet.


Post Extras: Print Post   Remind Me!   Notify Moderator  
xcy
sage


Reged: 05/15/06

Loc: Europe
Re: Can't accurately star align CG5-GT new [Re: Terrance]
      #3866716 - 06/15/10 04:37 PM

I finally got the chance to try the mount again tonight with a 6" f/5 Newtonian and this time I choose only two alignment stars and one calibration star. First alignment star was Regulus which was out of the field of view of the finder and second was Mizar which was inside the field of view of the finder, but not in the eyepiece. Calibration star was Vega which was way off. However, alignment was succesfull and every object I tried to locate was in the center of the field of view (except the ones I could not see, which were probably there too).

Is the first calibration star supposed to be out of the field of view of the finder and so far away?

This was also my first attempt to use the mount with a 12V 12Ah rechargeable battery. The session lasted about two hours and I did approximately 50 GOTOs with no apparent problems, but I was wondering if the use of such battery could cause a problem to the mount.


Post Extras: Print Post   Remind Me!   Notify Moderator  
jrcrillyAdministrator
Refractor wienie no more
*****

Reged: 04/30/03

Loc: NE Ohio
Re: Can't accurately star align CG5-GT new [Re: xcy]
      #3866909 - 06/15/10 06:21 PM

Quote:

Is the first calibration star supposed to be out of the field of view of the finder and so far away?




The accuracy of the first calibration star slew is dependent on the quality of the initial polar alignment, and on the orthogonality of the mount and optical tube. If polar alignment is off, or if the mount axes aren't square to each other, or if the tube isn't square to the mount, or if the optical axis of the telescope isn't aligned with the tube, the first cal star can be way off. That's a lot of variables. That's why the cal stars exist; without them, all goto operations on one side of the meridian would be subject to those errors.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Can't accurately star align CG5-GT new [Re: xcy]
      #3867827 - 06/16/10 07:56 AM

Quote:



Is the first calibration star supposed to be out of the field of view of the finder and so far away?






It MAY be. For best results, I usually keep adding cal stars until a cal star is in the eyepiece field of the main scope, or at least centered in the finder, which usually happens on the third star.

If, however, you are pleased with the results you are getting with just one cal star, there's no need to worry further. Sounds like your battery is workin' jus' fine.


Post Extras: Print Post   Remind Me!   Notify Moderator  
k1uhf
member


Reged: 03/11/10

Loc: PA
Re: Can't accurately star align CG5-GT new [Re: magnus]
      #4437917 - 03/09/11 04:33 PM

I have a CG5-GT with a 9.25 on it. Ever since I purchased it used it has not pointed accurately. Basically it almost never puts the object in a 40mm eyepiece and sometimes not in the finder. Also it will not go back to a calibration star after slewing to another part of the sky.

I have had this problem through two firmware upgrades. I am leveling accurately, and polar aligning with a polar scope. The power is with a fully charged lawn tractor battery and short low resistance lead.

The thing that has me going on this again is that I got a Nextar 60 GoTo for $40 on Craigslist and it works great, puts every object that can be seen in a 25 mm eyepiece consistantly.

There is much less slop in the gears on the CG5 than the little Nexstar too.

I wonder if there is something I am missing with the intial setup after a firmware update or if my mount has some encoder error problem. I don't want to send it back to Celestron, they will probably want to charge more than I paid for it.

Any ideas?


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Can't accurately star align CG5-GT new [Re: k1uhf]
      #4438170 - 03/09/11 06:35 PM

Quote:

I have a CG5-GT with a 9.25 on it. Ever since I purchased it used it has not pointed accurately. Basically it almost never puts the object in a 40mm eyepiece and sometimes not in the finder. Also it will not go back to a calibration star after slewing to another part of the sky.

I have had this problem through two firmware upgrades. I am leveling accurately, and polar aligning with a polar scope. The power is with a fully charged lawn tractor battery and short low resistance lead.

The thing that has me going on this again is that I got a Nextar 60 GoTo for $40 on Craigslist and it works great, puts every object that can be seen in a 25 mm eyepiece consistantly.

There is much less slop in the gears on the CG5 than the little Nexstar too.

I wonder if there is something I am missing with the intial setup after a firmware update or if my mount has some encoder error problem. I don't want to send it back to Celestron, they will probably want to charge more than I paid for it.

Any ideas?




Neither leveling nor polar aligning nor firware updating will have a signicant effect on go-to accuracy. What will?

--Always do final centering of alignment stars using up and right only.

--Be sure you are centering the correct star.

--Always start out with a fully charged battery.

--If you haven't done so, try a factory reset, too.


Post Extras: Print Post   Remind Me!   Notify Moderator  
k1uhf
member


Reged: 03/11/10

Loc: PA
Re: Can't accurately star align CG5-GT new [Re: rmollise]
      #4439393 - 03/10/11 09:11 AM

Yes thanks, Doing all of that. I might mention that I must use stars that are more than 30 deg above the horizon due to trees.

I just wonder why the little Nextar is so much better and why the big one will not go back and forth between the last two calibration stars and even put them in the finder?

The inability for it to go back and forth between the last two calibration stars, onese that are either side of the meridian, seems to indicate some problem. Maybe I have huge mirror flop, encoder mis-reading. Just seems like it should be able to point better than the low end model I also have.

Thanks
Del


Post Extras: Print Post   Remind Me!   Notify Moderator  
skywolf856
sage


Reged: 01/25/08

Loc: SE Michigan
Re: Can't accurately star align CG5-GT new [Re: k1uhf]
      #4440832 - 03/10/11 07:24 PM

Also pay attention to your time entry either standard or daylight savings.
I caught myself entering this one wrong once and my alignment stars were way off in left field.

Magnus,
My 8" f7 newt works great on this mount, just don't bump it.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rmollise
Postmaster
*****

Reged: 07/06/07

Re: Can't accurately star align CG5-GT new [Re: k1uhf]
      #4441724 - 03/11/11 06:25 AM

Quote:

Yes thanks, Doing all of that. I might mention that I must use stars that are more than 30 deg above the horizon due to trees.

I just wonder why the little Nextar is so much better and why the big one will not go back and forth between the last two calibration stars and even put them in the finder?




It's not. My CG5 and those of my friends are better accuracy wise than the little NexStars, comparable to the CPC/GPS scopes. If you have a problem it's because there's something wrong with your particular mount or your setup technique. I'd check with your local club and see if there's someone there with a CG5 who can give you some hands on help.


Post Extras: Print Post   Remind Me!   Notify Moderator  
HowardK
Pooh-Bah
*****

Reged: 10/20/10

Re: Can't accurately star align CG5-GT new [Re: rmollise]
      #4441916 - 03/11/11 09:36 AM

does anyone here know if the up and right button presses when finishing the centering of alignment stars also applies to the CGE PRO?

Howard


Post Extras: Print Post   Remind Me!   Notify Moderator  
mclewis1
Thread Killer
*****

Reged: 02/25/06

Loc: New Brunswick, Canada
Re: Can't accurately star align CG5-GT new [Re: HowardK]
      #4442341 - 03/11/11 01:20 PM

The HC code for all the Celestron gems (CG-5, CGEM, CGE, CGEPro) is the same so yes, if the HC code version is the same then a function on the CG-5 works the same as on the CGEPro.

Post Extras: Print Post   Remind Me!   Notify Moderator  
HowardK
Pooh-Bah
*****

Reged: 10/20/10

Re: Can't accurately star align CG5-GT new [Re: mclewis1]
      #4442531 - 03/11/11 03:02 PM

Thanks......there is no mention of this in the manual that came with the CGE PRO

Post Extras: Print Post   Remind Me!   Notify Moderator  
jrcrillyAdministrator
Refractor wienie no more
*****

Reged: 04/30/03

Loc: NE Ohio
Re: Can't accurately star align CG5-GT new [Re: HowardK]
      #4442668 - 03/11/11 04:16 PM

The up and right thing is essential on the single-arm forkmounts (no worm drives). It was on those that this fix was discovered. It helps on the CG5-GT (inexpensive worm drives). I've never seen it to matter on the better drives of the CGE and wouldn't expect it to matter on the Pro, either.

Post Extras: Print Post   Remind Me!   Notify Moderator  
HowardK
Pooh-Bah
*****

Reged: 10/20/10

Re: Can't accurately star align CG5-GT new [Re: jrcrilly]
      #4442849 - 03/11/11 06:01 PM

Oh.......so who is right?........does the up and right press matter for the CGE PRO?.......anyone tested this for sure?.......how will i know if it has any benefits next time out?

Post Extras: Print Post   Remind Me!   Notify Moderator  
mclewis1
Thread Killer
*****

Reged: 02/25/06

Loc: New Brunswick, Canada
Re: Can't accurately star align CG5-GT new [Re: HowardK]
      #4442890 - 03/11/11 06:28 PM

There's no right or wrong ... the function is there. The less slop or backlash present the less valuable the function is.

Is it useful on a CGEPro? ... try it and see if your alignments are any more accurate.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
27 registered and 42 anonymous users are browsing this forum.

Moderator:  Dave M, richard7, bilgebay 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 3812

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics