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)
Mitch Hamilton
journeyman


Reged: 01/25/14

Need advice before buying Celestron CG5 AS-GT.
      #6360680 - 02/06/14 09:06 PM

So I'm looking at an ad for a used Celestron CG-5 AS-GT computerized mount and the price is VERY good, but I'm just concerned that it's for a problem that will put me down a tough road. The ad indicates that the price is so low due to:

"an error code that says the hand controller has lost communication with one of the drives on the mount. I think it is the declination axis, because the mount slews non-stop in declination when I try to do a polar alignment."

My question is will this mount be a money pit? I am tech savvy and I have a fair grasp of electronics but are these mounts generally serviceable by an individual or am I going to end up having to send it in to Celestron at my expense?

Realistically speaking I don't have a budget for a new mount but if I don't go with this mount I'll probably save up money for another year and get the Celestron Advanced VX mount.

What should I do?

Thanks so much,

Mitch


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

Reged: 04/30/03

Loc: NE Ohio
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: Mitch Hamilton]
      #6360714 - 02/06/14 09:25 PM

That's usually caused by a bad encoder, which is part of the motor assembly. That wasn't too bad in the past (the motor assy used to sell for $29) but I think the current price is more like $150. If it isn't the encoder it's probably the motor control board which costs at least that much. Or you could hit the lottery and it's just a bad connection between the board and the motor and you can fix it for free. I believe that's the least common situation.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Stelios
Carpal Tunnel
*****

Reged: 10/04/03

Loc: West Hills, CA
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: Mitch Hamilton]
      #6360794 - 02/06/14 10:02 PM

Don't borrow trouble. If you were buying it as a potential extra mount and a fun project that would be one thing, but if you're buying because you are short of money, wait and get the AVX.

1) The AVX is a superior mount.

2) Even if you can fix the problem of the CG-5, you have no guarantee that that's the *only* problem with that CG-5. You could get into a chain of problems, and be spending money to fix every one.

3) And if you fix everything, you have a used mount that, realistically, will not live forever (I'm not down on CG-5's at all--I own one, love it, it's my only mount, and it's been working fine for 11 years. But I wouldn't spend more than $325 or so to buy my mount today--and mine *works*).


Post Extras: Print Post   Remind Me!   Notify Moderator  
RTLR 12
Post Laureate
*****

Reged: 12/04/08

Loc: The Great Pacific NorthWest
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: jrcrilly]
      #6360796 - 02/06/14 10:03 PM

The error code means there is no communication between the hand controller and the DEC motor. Remove the lower plastic motor cover and look at the 4 connectors on the MC board. The 2 connectors marked "ALT" and "AZM" are for the motors. Swap the 2 connectors and re-test the mount. If the DEC motor continues to run non stop, then you have a bad MC board, but if the RA motor now runs on and on, then you have a bad motor encoder.

The MC board ruins $107 and a new motor runs $132.

Stan


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mitch Hamilton
journeyman


Reged: 01/25/14

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: RTLR 12]
      #6360824 - 02/06/14 10:19 PM

To give financial context the asking price for the mount is $150. I'm still considering it for a "project" but all of your advice has made me quite weary.

Post Extras: Print Post   Remind Me!   Notify Moderator  
dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: Mitch Hamilton]
      #6360858 - 02/06/14 10:35 PM

Listen to Stan, he has 5 of them , Kasey

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

Reged: 04/30/03

Loc: NE Ohio
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: RTLR 12]
      #6360873 - 02/06/14 10:40 PM

Quote:

Swap the 2 connectors and re-test the mount. If the DEC motor continues to run non stop, then you have a bad MC board, but if the RA motor now runs on and on, then you have a bad motor encoder.




If he buys it, that's how to diagnose it - but I believe you have the symptoms backwards. If the dec motor continues to run away when connected to the RA output the dec motor is bad. If the RA motor runs away when connected to the dec output then the MC is bad.


Post Extras: Print Post   Remind Me!   Notify Moderator  
dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: jrcrilly]
      #6360883 - 02/06/14 10:47 PM

Also check the handset if its Nextstar+, I believe the ASGT should come with that model, Kasey

Post Extras: Print Post   Remind Me!   Notify Moderator  
RTLR 12
Post Laureate
*****

Reged: 12/04/08

Loc: The Great Pacific NorthWest
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: jrcrilly]
      #6360888 - 02/06/14 10:48 PM

John,

You're right. I was in a hurry when typing and misspoke. Thanks for the correction.

Stan


Post Extras: Print Post   Remind Me!   Notify Moderator  
Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: dragonslayer1]
      #6360895 - 02/06/14 10:55 PM

Well I am thinking if you have worst case of $132 for a motor added to $150 for the mount itself you have a CG5 for less then $300. Given it may be just a cable you may be able to get away with a CG5 for as little as $175 or so total.

At $300 a good working CG5 is a good deal, at $175 it would be amazing.

So if, and only if, the prospect of it being a bit of a work-to-be-done project is fine with you then it sounds like a reasonable deal to me! If the prospect of work/gamble give you an even slight hesitation though the AVX is indeed a slightly better mount and includes no "if" factor.

The one thing that would give me pause is if it is an early CG5 with the version 3.x handset instead of a version 4.x handset. The 4.x models can have their firmware updated, the 3.x ones can not, the 4.x ones have the All Star Polar Alignment feature, the 3.x ones do not.


Post Extras: Print Post   Remind Me!   Notify Moderator  
dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: Falcon-]
      #6360910 - 02/06/14 11:06 PM

I have a CG-5 ASGT and its really a good mount, Kasey

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

Reged: 04/30/03

Loc: NE Ohio
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: dragonslayer1]
      #6360918 - 02/06/14 11:09 PM

Quote:

I have a CG-5 ASGT and its really a good mount, Kasey




I've owned a couple. They are a very good value. Had to replace a motor in one, and had to bypass the power switch on the other. Such failures don't appear to be all that common; I wouldn't be afraid to buy another one.


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

Reged: 07/06/07

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: jrcrilly]
      #6361662 - 02/07/14 10:56 AM

Quote:

That's usually caused by a bad encoder, which is part of the motor assembly. That wasn't too bad in the past (the motor assy used to sell for $29) but I think the current price is more like $150. If it isn't the encoder it's probably the motor control board which costs at least that much. Or you could hit the lottery and it's just a bad connection between the board and the motor and you can fix it for free. I believe that's the least common situation.




OR...it could simply be a bad declination cable. However, unless you are willing to deal with it, don't buy a mount with known problems. OTOH, while the mounts can have encoder and other problems, most of the problems are pretty simple and relate to poor and dirty connections and poor power.


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

Reged: 07/06/07

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: dragonslayer1]
      #6361665 - 02/07/14 10:57 AM

Quote:

Also check the handset if its Nextstar+, I believe the ASGT should come with that model, Kasey




Only, perhaps, if it were one of the last ones sold.


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

Reged: 04/30/03

Loc: NE Ohio
Re: Need advice before buying Celestron CG5 AS-GT. new [Re: rmollise]
      #6361675 - 02/07/14 11:06 AM

Quote:

OR...it could simply be a bad declination cable. )




That would count as a bad connection between the MC and motor as mentioned above. I haven't seen one, though. Just a bad motor.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mitch Hamilton
journeyman


Reged: 01/25/14

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: jrcrilly]
      #6362159 - 02/07/14 03:02 PM Attachment (11 downloads)

This is the hand controller he has on the ad.

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


Reged: 03/11/08

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: Mitch Hamilton]
      #6362245 - 02/07/14 03:44 PM Attachment (4 downloads)

I'm in the UK, I broke my encoder a week ago and picked up a new Celestron motor & encoder from a dealer for £43 inc postage & 20% tax ($60) - came with wire connections and the mounting bracket as well

PS - If you are in the US, couldn't you just buy a new encoder from US Digital, I thought about it but paying delivery and import duty and tax it wasn't worth it for me

I stripped my old motor down so I can give you the shaft dimensions if you need them



Edited by steveor (02/07/14 03:49 PM)


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

Reged: 07/06/07

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: steveor]
      #6362255 - 02/07/14 03:47 PM

That is the standard (not plus) HC.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mitch Hamilton
journeyman


Reged: 01/25/14

Re: Need advice before buying Celestron CG5 AS-GT. new [Re: rmollise]
      #6362260 - 02/07/14 03:51 PM

I'm in Canada

Post Extras: Print Post   Remind Me!   Notify Moderator  
RTLR 12
Post Laureate
*****

Reged: 12/04/08

Loc: The Great Pacific NorthWest
Re: Need advice before buying Celestron CG5 AS-GT. [Re: Mitch Hamilton]
      #6362290 - 02/07/14 04:03 PM

Mitch,

That is an earlier series 3.XX non programmable hand controller...

Stan


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


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

Moderator:  Dave M, richard7, bilgebay, iceblaze 

Print Thread

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


Thread views: 574

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics