Posted 05 March 2013 - 11:35 AM
Posted 05 March 2013 - 11:44 AM
I'm currently only using the mount for planetary and the planets are some of the few objects I can find even if the go to is messed so I'm just dealing with it.
Posted 05 March 2013 - 07:49 PM
2) RA/DEC cabling issues - try different cables but also plan to do the Gary Bennett upgrade.
3) Limit switches need adjustment - these will cause all sorts of strange issues. They are quite easy to adjust, the best guidance for this is on the Yahoo CGE_uncensored group.
4) Internal connector issues - It can be useful to just carefully go over all the internal connectors. Remove and replace each one in turn, and check for poor connections with each wire.
Posted 14 March 2013 - 11:26 AM
Posted 14 March 2013 - 08:10 PM
Posted 15 March 2013 - 10:19 AM
Posted 15 March 2013 - 03:43 PM
Replacing the cables is not really cost effective and usually not necessary.
This is my opinion and my opinion only.
All of the Celstron mounts and the Meade LXD mounts I have owned have all mis-behaved over the years.
I replaced the cables on the CGE, and it did not really truly "Fix" the problem.
You can spend a lot of time and money on an upgraded cable system, but there is no need two.
The first thing that I have found will resolve the problem is to clean the sockets that the cables plug in to.
I believe that these contacts get either oxidation (they are supposed to be gold plated, to prevent this, but I doubt that anyone does this anymore, or loose tension.
Use DeoxIT and spray the contacts liberally.
These plugs are "Self Wiping" which means that as you plug and unplug them, the friction of one against the other is supposed to clean them, but if you don't remove and replace them regularly, I think the simply oxidize out.
About once every year, my mount will start over-driving in Dec. This is the main symptom I get that the software has corrupted. I have to do a hard reset to fix it, but if I don't clean the contacts, it will just come back.
Cleaning the contacts and in runs fine for another year (I never remove the cables when I take the head in or out, so no wiping takes place).
Once (after many years of ownership) cleaing the cables did not work. I removed the plate in top of the semi Pier and reseated every cable multiple times to wipe them. I put a new battery in at the same time. Mount worked fine after that but it has been about a year ago, so contact cleaning is almost due.
My mount will sit outdoors under a plastic cover for weeks at a time, so I am sure the exposure quickens the oxidation.
Replacing the cables can be a "Temporary" fix, because just replacing the cable will give the contact one "Wipe" and this may clean it well enough to buy you some time.
Someone said that the problem was grounding. I bonded the shells of the cables to the plugs and this did noting to resolve the problem, so I don't think that it is at all related to the failures people experience.
So, swapping the cables may "appear" to fix the problem, but it kept coming back for me.
But now, when it happens, I shoot some DeoxIT into the sockets and on to the ends of the cables and plug-unplug a half dozen times to wipe them, and away I go.
For about another year anyway.
So for me, the cables were not really a fix at all. Cleaning the cable sockets on the mount always gets me back into operation.
I had an LXD thought that kept failing. No amount of cleaing would fix it.
For this mount, I had to use a tiny spring hook and dig under the contacts on the plug on the mount that the HC plugged in to. I used this tiny spring hook (actually a tiny little crochet hook I believe) to re-arch the contacts in the plug. Fixed it.
Good luck with whatever path you take but if you clean the contacts and re-set the HC, my bet is that it will hum along fine for another year or two.
Posted 15 March 2013 - 05:24 PM
Replacing the cables is not really cost effective and usually not necessary.
That's right! It makes no sense. There is a very simple and very effective method to fix CGE cable problems. I am just amazed to see so many CGE owners who bought those super expensive replacement cables. It is just mind boggling to spend 25% to 30% of the mount value on cables!
Posted 15 March 2013 - 07:12 PM
Posted 30 May 2013 - 03:06 PM
Thanks for sharing
Looks like Gary Bennett made other TPI - Telescope Performance Improvements: http://www.bendun.net/
Posted 02 June 2013 - 09:36 AM
Edit: truly important: try to avoid cables pushing against eachother; in my setup, this happened whith the OTA at the western side of the mount, just before meredian flip. I installed a 90 degrees connector at the RA cable and modified cable length to eliminate this.
Posted 02 June 2013 - 10:17 AM
The secret is to get those stiff, stock cables, especially the Dec. cable, and replace them with Marty cables.
Posted 02 June 2013 - 01:26 PM
Posted 02 June 2013 - 01:54 PM
Posted 02 June 2013 - 04:53 PM
OK, but the cables Gary Bennet uses is also too stiff, in cold weather.
True, however, the modification eliminates the cable/socket combination and goes from that weak point to a soldered connection.
Posted 02 June 2013 - 06:59 PM
enter last night, i'm out at a dark site for my club doing outreach, got my mount all set up go to power it on and out of nowhere it goes and slews in RA for no reason. i'm like *BLEEP* what did i mess up when i put it back together. so after consulting with others there that have owned CG-5's and they are dumbfounded by it i go well it does stop slewing after a short while and it appears to slew to alignment stars correctly so i guess when it gets dark enough i'll just try to align it and see what happens right?
well needless to say it slewed to the first star very well as it should but then i go to center said star and every time i pressed the down arrow rather than turning in dec like it should all of a sudden it turns in RA at a rapid pace and then stars studdering and then stops. i'm like great somethings up big time here.
next i tried a factory rest. nope nothing still does it. then i tried reloading the HC firmware after finding that if i started it into programming mode it did not slew on power up like it was doing with normal power ups. nope another 10 min wasted.
finally i decided i should crack it open before it gets too dark and investigate. what do i discover? yep the RA motor ribbon cable was not seated fully into the MC board so i pushed it all the way in and powered it up while holding the electronics off the mount so it won't short and voila problem solved.
bad connections to the motors can clearly cause celestron mounts (and likely most all other brand mounts) to do all kinds of crazy things probably because they are not getting the proper signal back from the encoder in the motors is my guess.
Posted 09 June 2013 - 11:57 AM
Posted 10 June 2013 - 10:31 AM
I presently use Marty cables but most of my observing is done in moderate to warm weather. I use a different mount on very cold nights. Thus far, they have worked for me. But I do have the Bennett kit on the shelf for if and when the Marty solution no longer works for me. I'm also considering either picking up a low mileage "donor" CGE or a full set of replacement components from Celestron, or both. I do like the mount, and it's a shame that Synta cheaped out on the QC improvement cycles over the life of the design. It has brilliantly decent quality components, with a few pieces of junky compnents/casting and a couple of glaringly poor engineering design bits. This could have been a glorious mount that would have rendered Losmandy irrelevant prevented the slew of flaky Synta/Celestron mounts that followed, and provided users with a truly made in USA option with up to date, non buggy (*cough* Gemini II *cough*) electronics and software. But no. Penny wise and pound foolish won the day. The bronze gears in the CGE alone are worth more than all of the pot meal used in the CGE Pro combined.
I picked up a good condition AP900 QMD last week that I am cleaning and restoring. It will be revamped tested for a few weeks and then...go on the shelf for the day when my CGE can no longer be easily massaged back into working shape (or I get an observatory property, whichever comes first).
The key to any successful mission is redundancy of essential systems.
Posted 10 June 2013 - 12:56 PM
I'm with you on the general comments ... but I don't think there's much of any cold weather issues with Gary's cable upgrade. My CGE has been bullet proof over two winters since I did Gary's drill less cable upgrade (mount is in a POD). It was also pretty darn good using the Marty cables over the previous winters, one here in Canada and two more in Colorado (always stored in unheated garages). I upgraded to the Marty cables shortly after getting the mount ... even before I had any issues.
I don't think I've heard of any cold weather specific issues with Gary's upgrade from anyone else either. I guess it's possible, but with the connectors being threaded together and the lack of pulling on the boards most of the potential issues have been addressed. It would be cool if Gary B used a high silicone content cable to keep it more flexible in the serious cold ... but I don't know what the cost/benefit trade off might be for that type of change.
I'm not sure how many CGEs are operational here in the great white north but I don't hear about many folks complaining about cold weather issues with the few I know about (all have Gary's cable upgrade).
Posted 10 June 2013 - 01:08 PM
It has had no modifications. It has carried a variety of scopes and performed well. It has also endured hot and cold conditions including this one. After the snow and ice melted, it worked, and still does work fine.
I recently sold an A-P 900QMD (not to Jim) due to lack of use.
Posted 10 June 2013 - 06:41 PM
Posted 11 June 2013 - 09:58 AM