CGE Pro Review
By Jim Welisek
I was thinking about purchasing a CGE Pro for my observatory, but an early morning lightning strike made the decision for me. Besides some stuff around the house, the old CGE was dead. Off it went to Celestron for repairs and the CGE Pro was ordered from OPT.
The CGE Pro in the observatory. An important consideration for those using the older CGE is that the CGE Pro is 8 inches taller than the old CGE. For some reason the saddle plate knobs are also on the other side of the Pro when compared to the CGE. The Pro mount also comes with only one 22 lb weight.
When the CGE Pro arrived, the first thing you notice compared to the CGE is that it is massive. The mount is about twice as tall, 1.5 times the weight and larger in diameter by two inches. If you are replacing a CGE in an observatory you’ll have to do some measuring and possibly pier adjusting because it is 8 inches taller. I built my pier with a spacer and was able to cut it down the eight inches to keep the C14 at the same height inside the dome.
I was planning on using the CGE Pro mainly in the observatory and had heard it really doesn’t lend itself to being real portable. Once I unpacked the mount and tried to move it I realized it is about as “portable” as an outboard boat motor. The mount is heavy and tall and with all the pencil-like RA and Dec knobs sticking out, if it fell over it would certainly do damage to itself and whatever it fell on. In short, the CGE Pro is more of an observatory/fixed mount and does not lend itself to portability.
Portable is a relative term. At about 45 lbs I consider the regular CGE at the upper end of “reasonably portable”, the Pro is definitely beyond that. The mount can break down into two pieces, but it is a 60 lb piece and a 15 lb piece. I have never broken the mount down but I’m sure it would still be considered heavy lifting by most. Before I had the observatory I used to lug my 70 pound 10” SCT out every time and just got used to it, perhaps one would get used to lugging the Pro out but it would be formidable.
Another portability issue is the RA and DEC knobs. They are long and pencil-like and stick out all over the place like a porcupine. Unlike the regular CGE that had small levers that folded away, these RA and Declination knobs would have to be removed for transport if you want to lay the mount down or box it. It’s not a huge issue, but one more thing to deal with if going portable with the mount. If the mount could be strapped in a car seat it probably could be transported assembled, but boxed, you are definitely going to need disassembly and a truck bed or very large car trunk.
The mount and tripod arrive in two very large boxes. Naturally the first thing I did was set it up in the garage to play with it. Within 5 minutes I was scratching my head. The counterweight bar would not thread into the lower mounting plate more than a couple turns. It was clear that the threads were binding and something was definitely wrong. I could tell if I tried to force the bar in it would most likely weld in place. I have a friend with a fully equipped machine shop and ran the bar and the mounting plate over to him. After a few measurements he determined that the metric threads on the lower mounting plate were not cut properly and were too shallow. He was able to chase the threads on a CNC machine and “took quite a bit of metal out”. Evidently the parts were never quality checked for proper tolerance or fit and just packed in the box. This concerns me as this is Celestron’s flagship product. Had I not had a friend that could do the repairs it would have meant a trip back to Celestron right out of the box.
The mount went out into the observatory and the C14 was mounted up. The first night was spent drift correcting. The second night was spent trying to figure out why the RTC (Remote Time Clock) would not remember the time. After getting it all drift corrected I had to pull the mount to try and figure out why the RTC wouldn’t work. With help from OPT I inspected the cables and connectors inside the electronics pier and replaced the battery. Nothing helped and it turned out the RTC board itself was bad. Once again, this concerns me about the flagship product of a company.
On this one I had no choice but to send the electronics pier in for repairs. OPT offered to swap out the electronics pier with a new unit so I could avoid dealing with the Celestron repair staff and department, (Much thanks and kudos to OPT for that one). So after receiving the mount there was a two week delay before I could really use it.
After a couple of weeks I was finally in business with a functioning mount. The first thing you’ll notice about the mount is the ‘stylish’ lines, curves and holes. It definitely looks good if you like sculpture. The second thing you will notice about it is all the knobs. Put the two together and the mount looks like someone made modern art out of a turn of the century steam engine.
If you prefer functionality over fine art, there are some issues with all the knobs. Between the eight pencil knobs on the RA and Dec clutches there are also eleven round knobs for altitude and azimuth adjustment and three more pencil knobs on the saddle plate. A total of 22 knobs! Some knobs are long and pencil-like on the RA, Dec and saddle plate knobs. The rest are small rosette type knobs for altitude and azimuth adjustment.
Knobs are great for field setup, (instead of using allen wrenches like with the old CGE). For a mount that I am basically using in an observatory all these knobs are simply cable snags waiting to happen. One CGE Pro owner told me that he has replaced all the knobs with allen screws. It seems a backwards step but for an observatory mount it may make sense.
From a functionality standpoint, the size and placement of the knobs is also an issue. There are four round knobs around the base of the mount to lock down azimuth adjustment. The knobs are difficult to grab hold of because of their size and closeness to the vertical sides of the mount. One is buried by the altitude adjustment knob and is especially difficult to tighten. The pencil knobs on the clutches and saddle plate are so skinny that they are difficult to tighten with fingers and have to be palmed. One of the pencil declination knobs is directly under one of the pencil saddle plate knobs making it difficult to tighten either one. The close proximity of these two knobs also makes it easy to accidentally loosen the saddle plate knob when trying to loosen the clutch knob, especially in the dark. The worst offender is the altitude adjustment knob on the south side of the mount. It stands out like a unicorn’s horn waiting to grab any cables that swing past in a mount flip. Basically I found there is virtually no way to run any cabling safely off the south end of the telescope without risking cable snags on all these knobs. It can be done, but all these knobs will happily grab camera cables, dew heater cables, anything that passes them. At least running the cables off the front of the mount minimizes the cable risk.
The altitude adjustment knob is on a bridge between the two sides of the mount. There are two positions for the bridge depending on the user’s latitude. If north of about 30 degrees, two allen screws need to be removed and the bridge moved to the lower setting. I don’t believe this was in the documentation but is pretty intuitive when you see it. The altitude knob pushes on the bottom of the altitude shaft which rocks it in the mount cradle to adjust altitude. This is the most offending cable snag knob. Once the mount would be aligned and if securely locked, the knob could be removed from the mount. I’ve left it on since I’ve found ways to route the cables safely and to ensure that the weight of the mount in altitude is supported.
One last “knob issue” is the RA knobs swing over the RA motor housing. One of my video cables got trapped between the motor housing and RA clutch knob and if I hadn’t noticed and stopped the mount it could have seriously damaged the cable or broken it.
The mount also slices and dices at no extra charge! Note the RA clutch knob extending out just to the right of the RA motor housing. At one point I almost cut a camera cable in half that got between that RA knob and the RA housing during a slew. The RA knobs travel right over the motor housing and can hang up a cable and then try to slice it off on the RA housing. Outside of that, the photo above shows some of the 22 knobs that are on the mount and their potential as cable snags. The photo above is early on where I had some of the cables run off the back of the mount. The safest way to run cabling is off the front to avoid all the knobs as much as possible.
On the positive side of all the knobs, they do make alignment much easier and movement is smoother than the CGE. If you are planning to use the CGE Pro in the field, this will be a plus.
There are three saddle plate locks as opposed to the two on the CGE. This adds some additional rigidity. If you are familiar with the CGE, for some reason the saddle plate lock knobs are on the opposite side for the CGE Pro. Although I haven’t tried it with the C14, it looks like the dovetail plate opens wide enough to “rock in” a dove bar rather than having to line it up and slide it all the way down.
From a mount cable standpoint Celestron eliminated out of the CGE’s major shortcomings. Instead of RJ45 plugs, the RA and declination cables have metal screw-in collars. This has eliminated the “run-away” problems the CGE was plagued with. As a little touch, Celestron includes threaded rubber caps hanging on chains to plug the cable holes when the mount is in transport. The rubber is so soft they really don’t thread but more “press on”. When the mount is in operation these little caps on a chain dangle like earrings. I don’t know that these are all that important but I guess add a nice touch.
The metal collared, screw-in cables are a huge improvement over the RJ45 jacks the old CGE had. This is the kind of improvement I was hoping for with the Pro. Note the little rubber cap (the gray thing) beneath the cable connector. These rubber caps are cute and chained to the mount so they don’t get lost. There are four of them and they hang and dangle. This one I have the chain flipped over the cable to kind of get it out of the way.
Just like the CGE, Celestron does something I just can’t fathom. The cheap cigarette lighter power plug has a cable long enough to wrap around the observatory three times. It is literally 20 feet long! Unless you’re powering the mount from your car parked 20 feet away, the extra cable length and bends from folding it up is just creating additional electrical resistance. I can’t imagine anyone having a battery power source located more than 6 feet from the mount. It would not be a bad idea to replace the power cord with one that is shorter and more heavy duty. The Pro draws about 3 amps with both motors running. One positive on the power cord is that it has a threaded collar that screws into a mount fitting on the pier. This is finally a good approach to keeping the power cord from falling out. All Celestron mounts that I have owned have had an issue with easily bumping out the power cord. Typically the connector Celestron uses is a split pin design and occasionally the individual blades of the pin need to be carefully opened to keep the cord from falling out. The Pro with this collar on the power cord eliminates this issue. It also makes it a little more difficult to replace the power cord with a shorter, heavy duty one unless you want butt-splice the original “M” connector and collar on it.
Where Celestron gets generous on the power cable they go cheap on the hand controller cable. It’s the same hand controller as the CGE and the coiled, hardwired telephone cord is all of two feet long. More than once I’ve had the hand controller snap out of my hand like it was on a rubber band. One of the first modifications I did when I got the original CGE was to crimp up some ribbon cable and make a three foot extension cable for the hand controller. I just can’t figure how Celestron can give you 20 feet of power cable where you don’t want it and only two feet of hand controller cable where you do.
The mount comes with one 22 lb counterweight, but I actually have to use three or four almost to the end of the counterweight bar with all the gear I have hanging off the C14, guidescope, cameras etc. The CGE Pro is rock steady compared to the CGE. The CGE wasn’t bad, but if I bumped into the CGE the image would wiggle some like you would expect. The CGE Pro is like bumping into a rock.
The hand controller is identical to the one on the regular CGE. If one is familiar with running a regular CGE or any of the other Celestron models there is no learning curve. If you have not worked with a Celestron hand controller, they are pretty similar to everything that is out there. Goto’s on anything you’d want to see, precision goto’s etc. Just like any other LED controller I’ve ever had they cold weather performance is poor, the display slows down and dims. Normally for winter operations I rubberband a heat pack to the back of the controller but there are also heated pouches etc for sale. If you do computer control, connecting to the mount is the same RJ11 “phone cord” plug in the bottom of the hand controller.
The pointing accuracy is pretty good, maybe a little better than the CGE but not “spot on” like some mounts I’ve used. Much depends on the accuracy of the alignment stars, calibration stars, if you are “synched” to an object, done a mount flip or have flexture in the optical/imaging train. The pointing is acceptable but occasionally misses the mark because of these other factors. The mount is moving a lot of weight and gear but seems to handle it easily without straining. Typically I’m running the C14, 100mm guidescope, Hyperstar, imager, guide head, heaters and cables and roughly 80lbs of counterweights. The mount never seems strained. The advertisements rate it at 90lbs and as a rule of thumb I never try to load a mount up much beyond 2/3rds of the weight the vendor claims. The CGE was rated at 60 lbs and did ok with the C14 and gear, but I never ran a guidescope because of the extra weight. The CGE Pro seems to handle the whole load including the guidescope without flinching.
The mount’s actual performance at tracking does pretty well. I have noticed some occasional annoying “jumps” in RA while guiding, but haven’t determined if it is an issue with the guider or the scope. I’m assuming it to be an issue with the guider which is getting fairly old. For the most part, I’ve been able to take images up to 3 minutes unguided with reasonable stars. I’ve run some informal tests with my STV after drift correcting. Celestron advertises the accuracy as plus or minus nine arc seconds out of the box. I didn’t do extensive testing in all areas of the sky, but found the mount to perform within that 18 arc second window. This is beyond a doubt head and shoulders above the CGE. I never checked the error on that mount because if I ever wanted to do long exposures it meant using the guider. With just a PEC train with the STV (I haven’t done any refining with PemPro yet) I was averaging about 4 to 6 arc seconds of error. I’m sure there is room for improvement that I haven’t made yet. The image below is a 3 minute unguided Mallincam Xtreme shot at f1.9 with the Hyperstar.
This is a three minute unguided image of the Horsehead. Most of my imaging these days are Mallincam broadcasting on NightSkiesNetwork.com. I’ve found that I rarely need the autoguider with exposures of a few minutes. Occasionally I will get some RA shift but for the most part the tracking appears to be within the advertised +-9 arc seconds. Early tests that I ran were showing an total error of about 16 arc seconds over a worm cycle.
Am I happy with the mount? Basically yes. The mount does its job. It holds the OTA, goes to where I want it to go and tracks the object. That’s pretty much it. I think the mount could have been better designed and thought out with regards to all the knobs, their size and their placement. Celestron fixed some things with the Pro that the CGE lacked, tried to fix others and missed the boat, but they did come up with a midrange priced mount that does perform well.
Bottom line, as they always seem to ask in online reviews “Would I recommend the product to a friend?”
At this point I would have to reluctantly say no, for a couple of reasons. The first issue is with the obvious lack of quality control that went into a five thousand dollar “flagship” product. Granted my CGE Pro may be “the only one that slipped by” when the QA folks were snoozing, but I can only go by what I have experienced. If the mount had come out of the box in good working order, I probably would have recommended it. So then the real question comes down to what the real open box failure rate on the mount is. When spending $5,000 dollars, the failure rate should be zero.
The second issues is not directly related to the CGE Pro but to the CGE sent in for repairs. Apparently Celestron is so backlogged with warrantee work, that non-warrantee work regularly goes well beyond the “repair time estimate” (even though the repairs have to be paid for in advance). It leaves me very concerned with what kind of service to expect when the Pro needs out of warrantee service. Hopefully by the time the CGE Pro needs service the Celestron backlog and turnaround time will be better.
Although the CGE Pro has some shortcomings with its design it is a good performer.