CG-5 Computerized Mount

First, let me say that it saddens me to write a negative product review. Up to this point, I've never had any issues with any telescope product from any company. However, I feel Celestron has some serious issues they need to work out. I received this mount in mid January. Right out of the box, the RA board would not communicate with the hand controller. After some searching around, this appears to be a common problem. I contacted Celestron customer support. That day, the motor drive, hand controller, and DEC cable were sent out under warranty for repair and/or replacement. After three weeks, I received a replacement. However, Celestron failed to return the hand controller and DEC cable. Celestron claims an email was sent to their repair department to send me those parts. However, they do not provide a confirmation email or tracking number. I'm terrified to think it could be another three weeks before I receive them, if I receive them at all. Even then, there is the possibility that the communication problem will exist in this RA board as well and I'll have to go through the whole process again.I have owned this mount for a month now. I have yet to be able to use it. The purpose of this review is to inform buyers that there is a potential hassle factor to consider with this mount and its tech support.UPDATE: I did finally receive the hand control and DEC cable. This time everything worked great. If you don't have the polar axis finder, the mount has a built in "polar align" feature which works nice. I'm pleased with the function of the mount but I chose three stars to reflect dissatisfaction with the whole support experience.

The CG-5 GT is a Chinese made mount rebadged by Celestron, and fitted with Celestron's Nexstar computer control system. It looks like a clone of Vixen's Japanese made, Great Polaris mount. That mount had a reputation of being well made, and operating smoothly. The CG-5 in it's earlier incarnations had a reputation of being rough around the edges, and was packed with a hard, waxy grease that stalled the mount when it got cold. Go on-line, and you will see reviews praising the mount once you disassemble it, smooth the bearings and gears, and repack everything with better grease.The mount I received seemed pretty smooth. If possible, it moves even more smoothly than my old Great Polaris mount, and there is no play in the axes. Since I live in the tropics, I'm not likely to test the consistency of the mount's grease job. After a few weeks of operation here is what I have found:The sucker is rock stable, practically bomb proof. A 19 pound, 6", f6 tube assembly damps in less than half a second. This compares to about 4 seconds with the Great Polaris. Where the Japanese mount needs vibration suppression pads; the CG-5 GT doesn't. I credit the massive tripod that Celestron bundles with it. From the 2" wide legs to the massive bolts that attach them to the massive mounting platform, everything screams solidity. The actual mount head looks puny in comparison. Sure the combination looks funny; yes, the tripod adds weight, but the mount accomplishes its prime objective: It holds the telescope steady.As delivered, the CG-5 operates from latitude 30-60 degrees, i.e. most of the continental United States, Canada and Europe. To reach lower (I live at 21 degrees north), you need to remove one of the latitude adjusting screws, along with the base plate that holds it. It's hard to see the pointer for the mount's latitude scale. This being a German style equatorial, the unit comes with an 11 pound counterweight. I need 15 pounds to balance my scope (yes, Great Polaris weights work, so do their dovetail scope mounting brackets).It lacks a sighting scope for the star Polaris. Instead, you eyeball the star through the hollow right ascension axis. For visual work, this is fine. Given the computerized drive system, you probably don't even need to do that. For better alignment, you can buy the optional alignment scope, use the computerized polar alignment routine (which is actually pretty nifty), or use the tried and true drift method.Speaking of the computer, the mount comes with the Nexstar hand controller. The controller and the software have been around for a while, and it shows. The main alignment routine is the "Two Star Alignment." You should stretch that out to four stars. If you take the trouble to do that, you can do what I did: I slewed from the deep western part of the sky, to the far east, and got a slightly off center view of the target object at 135x. Very impressive.The Nexstar hand controller also has a phone jack that allows it to talk to your laptop, or other computer. You don't need to connect another computer; the Nexstar controller is more than adequate, but amateur astronomers will insist on playing with their toys. ;) Celestron sells a far too short RS-232 to phone jack cable for too much money to make the connection. Most laptops lack an RS-232 port, so you will also need to spring for a serial to USB connector.Then there is the software side. I use Cartes du Ciel for Linux, plus additional communications software called INDI (Windows users tend to use ASCOM). You also need to know port addresses, the name of your USB connection, computer geek stuff like that. Then comes the moment when you launch the Cartes du Ciel's control panel, and click "Connect." It is magical when the mount reports back that it is transmitting its position to the software. Sure enough, there is a new reticle on the map, showing where the scope is pointing (or would be pointing, as I have only tested this in my living room). I right click a different object, select "Telescope," click on "Slew," and hear the rather loud mount lumber into action. The reticle shifts to its new location. Geek heaven! ;)Some concluding thoughts.The CG-5 GT's nearest competitor is the Orion Sirius EQ-G, made by the Chinese company, Synta. It differs from the Celestron in having a slightly heavier duty mount head, periodic error correction, a polar alignment scope, and $500 higher price tag. What it lacks is Celestron's rock solid tripod, or Celestron's more advanced electronics. Now that Synta has purchased Celestron, I will be interested to see what happens to Synta's or Celestron's mount line-ups. For now, there is no other mount that delivers so much for so little.Update (3013-02-11): I have repeatedly run into a problem with the power cord to the mount working loose. The mount loses power, and you either have to try to recover your alignment, or go through another two star alignment process. The power chord is supposed to screw onto the mount itself, but is blocked from doing so by a plastic flange that intrudes too close to the plug-in socket. I disassembled the plastic covering for the RA motor and electronics, and ground down part of the flange next to the power socket. I then reassembled.I have given the new arrangement one night of heavy use, and I never lost power. This is a basic design flaw on Celestron's part, and warrants a one star reduction in rating.I notice that there are few, if any comments about this mount as an astrophotography platform. I am no astrophotographer, but here are my comments. The mount comes with an autoguider port. In theory, that means you should be able to plug in your autoguider device, and go. Two items may give trouble:First, this is a cheap mount (I view that as a good thing). Cheap mounts often don't show the care required to smooth the gears. Such care reduces both the amplitude of the mount's periodic tracking error, and eliminates any sudden tracking error movements. Computerized periodic error correction is a somewhat cheaper way of accomplishing the same thing, but the CG5-GT doesn't have it.Second, the mount uses cheap motors. Cheap motors often suffer from a phenomenon called "cogging." This is the tendency for the motor to resist a command to advance small distances (and I mean very small ones), such as the corrections given by an autoguider. Reading the comment threads at various astronomy sites shows that this problem affects both this mount and the heavier duty Celestron CGEM. The issue usually shows up as erratic drift in declination.Certain people offer "Hypertuning" services (for another $300, or more). Hypertuning would address problem one. You can reduce problem two by doing a scrupulous polar alignment before doing astrophotography (i.e. using the drift method). The alternative is to spend "real money" for a higher quality mount.Update April 2019: I see the mount is still available used, so what the heck, here's an update. Two of the three tripod leg clamps have broken off. I replaced them with straight brackets. I have had to shim the tripod feed to keep them from sliding off. That, too, was pretty easy. In the mean time, the mount has worked steadily and reliably. It currently carries a 7" Maksutov without complaint.btw. I see the used price for the mount is $1000. That is extremely overpriced for a mount this age.Update September 2020: The mount still works and is getting a workout on Jupiter, Saturn, and Mars. With the help of a second, smaller counterweight, it is currently carrying a 180mm Maksutov.

I bought this mount in February of 2012.This mount has a learning curve and the manual is not quite up to par, but then I am a slow learner. For instance, it took me over a month before I realized that the telescope has a feature called the "Meridian stop". This means that the mount will not track your object from east to west when it crosses that magic line called your meridian. You must manually reset the mount to the other side of the meridian. This is a feature of all German equatorial mounts.Next it takes a while to learn how to do polar alignment. For visual observing of bright objects the quick alignment feature is adequate. If you want to find faint objects, you must get serious with polar alignment. You should, that is, must buy the polar alignment scope which looks like an eyepiece that slips into the declination axis and allows you to sight the north star.Then my trouble started. Over the course of several months the mount would suddenly stop when it was moving to find an object. Given the unusually cloudy weather we have had in southern California, I had little opportunity to take the scope out and figure out what I did wrong. However over time I tested it enough and was able to reproduce the error sufficiently that I now know with 100% certainty it is not my lack of knowledge about the mount, but the mount is faulty.I have called Celestron 4 times over the last 3 days. (You cannot return to the vendor if it is over 30 days from purchase). Each time I was on music hold for at least 1.5 hour to 2 hours when the system just disconnects me. I went to their web site and submitted an RMA request for repair and I have received no response other than an automated email which show no status.I have heard Celestron was a good company (better than Meade) but I if they don't support their products you may have a worthless investment like I have now.If they ever get around to answering me and repairing it under the 2 year warranty, I will update this review.11 Jan 2012- Latest update. First, I got the mount replaced and the replacement runs beautifully even with just "OK" polar alighnment, that is, without using a polar scope. After 2 alignment stars and one calibration star, the mount was nailing objects within the field of view of my 27 mm Panoptic eyepiece. After adding 3 calibration stars, it nailed objects within my 9mm Nagler eyepiece. It even "talks" to Software Bisque's THeSkyX perfectly through the hand controller without a hitch. So I clearly waited tooo long - always thinking I was doing something wrong.So, I eventually got OPT to take back and replace the mount. The very next day I finally got a call back from Celestron.Bottom line I love the mount - now - but like another reviewer here, Celestron probably has some quality control problems with their electronics. If you have any problem with your mount, take it back as quickly as possible for a replacement.

You can't tell how big this thing is from the picture. It's a brute of a tripod. I upgraded from the base on an 130 SLT. It made a huge difference.