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CGE Mount not moving towards East in Declination

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#1 JPGriffin

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Posted 14 February 2011 - 09:36 PM

I have a new to me Celestron CGE Mount. I get stuck in the switch position portion of initializing the mount. The mount does not want to move eastward along the declination axis (mount is facing North). It moves westward fine and the RA motion seems normal.
I tried adjusting the declination switch but it doesn't make a difference.
I get the mount out of the switch position mode by loosening the clutches and manually triggering the declination switch. I can then proceed with a 2 star alignment. The mount slews towards the target star, but still will not move along that one direction in declination. It corresponds to the 'down' directional arrow on the hand controller.
I have, in addition to adjusting the declination switch, reseated all of the connections inside the declination motor housing and reseated the declination cable connections to the mount and motor.
Any advice or experience with this issue would be much appreciated. :question:

#2 zawijava

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Posted 14 February 2011 - 10:16 PM

I have a new to me Celestron CGE Mount. I get stuck in the switch position portion of initializing the mount. The mount does not want to move eastward along the declination axis (mount is facing North). It moves westward fine and the RA motion seems normal.
I tried adjusting the declination switch but it doesn't make a difference.
I get the mount out of the switch position mode by loosening the clutches and manually triggering the declination switch. I can then proceed with a 2 star alignment. The mount slews towards the target star, but still will not move along that one direction in declination. It corresponds to the 'down' directional arrow on the hand controller.
I have, in addition to adjusting the declination switch, reseated all of the connections inside the declination motor housing and reseated the declination cable connections to the mount and motor.
Any advice or experience with this issue would be much appreciated. :question:


Have you tried resetting to Factory Settings? Previous owner may have some Horizon Filter settings programed in. I'm far from being an expert on this mount, as I to recently purchased a pre owned CGE. But I've been using and studying....there's allot more to the Hand Control than meets the eye. Tried the CGE Users Group on Yahoo :question:

Tim

#3 David Pavlich

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Posted 14 February 2011 - 10:19 PM

Did you try switching the cables? You might also try a set of cables from Scopestuff. There's a better set we affectionately call Marty Cables, but for some reason, my shortcut doesn't work. These cables are a lot more flexible and will cause less stress on the Dec socket. I'm sure someone else will link to the cables.

It's either the cable, the socket or the switch, more than likely. Try sticking the RA cable in and see if that helps. Also, open up the RA motor cover and watch the switches when you move the mount in RA by hand to see when the switch should activate or stop. The adjustment is VERY sensitive.

Edit: The recommendation about resetting to the default settings is a good idea. Also, I found the Marty Cables. Scroll down to the second section and get yourself a couple of 3 footers.

David

#4 jrbarnett

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Posted 14 February 2011 - 11:15 PM

With the CGE, always suspect the RA and Dec cable connections when any unusual behavior occurs. Try and jiggle the RA and DEC cables gently in their sockets (where they enter the pier). If you haven't already done so, swap the stock cables for Marty cables. The numero uno failing of these mounts is the lousy, never-corrected and never-improved RA and Dec cable socket design.

There are aftermarket kits for correcting Celestron's socket design flaws.

http://bendun.net/cg...t_kits_Main.htm

Regards,

Jim

#5 Joe Cipriano

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Posted 15 February 2011 - 02:27 AM

I'll third that. The socket contacts are known to get cruddy/corroded, depending on conditions. You can clean the contacts in the sockets (standard RJ-45 jacks) with a pencil eraser, but you need to use almost no pressure, as the pins are easily bent. You can also try cleaning the cable contacts the same way. If you have access to cat5 SHIELDED cables, you can switch the mount's cables out for a known-good pair (unshielded cables will not work). If not, the company David provided the link to supplies them at a fair price.

Edit: The quickest way to find out if the cables are causing the problem is to exchange the Dec and RA cables. If the Dec starts working properly and the RA flakes out, the cable's the issue. If not, it's one of the Dec sockets (EQ head or pier) - or some connection/wire inside the mount itself.

#6 Twilight

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Posted 15 February 2011 - 02:56 AM

Have you checked for bent pins in the connectors?

#7 JPGriffin

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Posted 15 February 2011 - 07:48 AM

Thank you to all who responded for your advice. I will try the cable switch later this morning to see if I can transfer the problem to the RA side of things.
I believe my mount already has the upgraded hardware that Jim (jrbarnett) pointed to in his web link. Instead of a standard RJ45 jack, I have the rounded 8 pin connectors with a screw in collar for both the RA and declination cables.
I will post follow up once I switch the cables from RA to declination.
Thanks again for the advice.

#8 David Pavlich

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Posted 15 February 2011 - 09:01 AM

Since you have the custom cables, forget the Marty cable reference. If the cable switch doesn't work, it comes back to the switch or the cable socket. I would check the wiring leading to the socket. It could be that one of the connections is bad.

David

#9 LLEEGE

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Posted 15 February 2011 - 09:19 AM

I'd check the microswitch with an ohm meter. (power off, of course)

#10 JPGriffin

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Posted 15 February 2011 - 03:12 PM

Well I got the mount working. Thank you all for your suggestions and taking your time to respond to my "call for help."
1. I tried switching the cables and I could not replicate the issue with the RA motor.
2. Checked that there were no bent pins and the connections were nice and tight.
3. I opened the Declination motor housing and checked all of the connections. Everything seemed tight and secure. I disconnected and reconnected everything. Nothing was loose and no wires seemed frayed.
4. I switched the QC1 and QC2 plugs - no declination movement at all.
5. I switched them back and EUREKA - declination was moving correctly and I was able to get through the 'switch position' portion of the mount initialization.
6. I replaced all of the boards into the housing and tightened everything down and BAM - the problem was back!
7. I loosened the screws that were holding down the motor board and everything was working perfectly again.
8. I tightened the board snug again and the problem returned. I loosened the board and the problem disappeared.
9. So, the motor board was too tight and must have been pinching a wire or stressing a connection.

I am so glad that I tried out the mount during each phase of reassembly or I wouldn't have found the problem.
Thanks again for all of the advice.

#11 Asimov

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Posted 15 February 2011 - 03:19 PM

Well that is indeed very interesting. Glad you got it sorted. Are you going to request another board from C or just go with how it is? I'd probably be happy just to get it working.

#12 Joe Cipriano

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Posted 15 February 2011 - 07:27 PM

6. I replaced all of the boards into the housing and tightened everything down and BAM - the problem was back!
7. I loosened the screws that were holding down the motor board and everything was working perfectly again.
8. I tightened the board snug again and the problem returned. I loosened the board and the problem disappeared.
9. So, the motor board was too tight and must have been pinching a wire or stressing a connection.


I'd consider replacing the board. IMHO you've either got a bad solder joint or a bad PCB trace (the "wires" on a printed circuit board). It sounds like the board is flexing slightly when you tighten it down, breaking the connection. When you release some of the pressure, the trace reconnects. You can probably use it as is for a while, but expect it to flake out with temperature changes, mount setup/break down, or pretty much whenever it feels like it.
Intermittant PCB problems are frustrating.

#13 David Pavlich

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Posted 15 February 2011 - 10:22 PM

I replaced the Dec board on a CGE that I had and I took pictures!! Here's the thread.

David

#14 faltered

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Posted 16 February 2011 - 02:55 PM

Before you do anything else - tripple check that your plugging in the RA to the RA and the Dec to Dec. If you have them mixed up, the mount will perform exactly like your describing. I fell for that one time, drove me crazy for 2 days, then FINALLY figured it out. I had the cables mixed up.

#15 orlyandico

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Posted 17 February 2011 - 12:56 AM

What Joe said.

The board probably has a cracked trace. OTOH you can eyeball the board (look for a warped section) maybe you could see the crack or break.

Scrape off the insulation over the cracked section and solder a piece of wire to bridge it. This would only work if the trace is wide and not right up next to a bunch of other traces.






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