Celestron CGE Mount 1 Long Term Review

Celestron CGE Mount & Tripod Review, (updated 2008)
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I have been using the CGE complete with C11 scope for 4 years now. After the 1 year I wrote an
initial review so I think it’s about time I followed with an update to include more long term aspects
of owning and using this mount.
This is review of the CGE mount & tripod only; I have not
included the telescope because there are already many
excellent reviews of the scope available on the internet and
in magazines but there is a distinct lack of meaningful
reviews to prospective owners on the CGE mount.
I say meaningful, because the only reviews I could find prior
to purchasing the mount were by magazines, who IMHO
tend to be a little biased towards suppliers/manufacturers to
whom they are selling advertising space. Magazine reviews
also tend to be based on short term tests.
So here it is; a warts and all long term review of the
Celestron CGE Mount.
On Opening the Boxes
This mount is BIG and heavy!
For mounts with scopes up to 11” the mount comes in 3
cardboard boxes containing the following:
1 off 25lb Counterweight, (C11), (C8s have 11lb weight, C14s have 2 x 25lb weights)
1 off Tripod, including spreader.
1 off Mount, including Head, Electronics Column, Cables, Hand box, Screws & Manual.
Unpacking and first set up with any mount is a joy and the CGE is no exception, when
assembling this you get a feel of quality and stability.
Then you step back and look at it and realize this mount is in no way a grab and go mount, you
need a good 15 – 20 minutes just to set it all up and that’s without switching on and aligning. To
me this was not a problem because I intended to house it in a permanent observatory but for
those looking for portability and quick set up, I would advise you hone your handling and set up
skills and start body building now. My record set up time from planting the tripod to viewing was
15 minutes and that’s with hauling the mount and scope out of a car boot so it can be done.
Weights:
Tripod
Electronics Column
Head
Counterweight
Dec Shaft
38lb
3lb ish
42lb
25lb
5lb
As you can see, setting up will give you a good workout and with an all up weight of 113lb, (8
stone), without scope, you had better make sure it sits on firm ground because it WILL sink into
your prized back lawn.
Mount
The mount bears a passing resemblance to the Losmandy G11 and the Ci700, but Celestron
have taken the G11/Ci700 concept and made it their own with the CGE.
The first thing to notice is that there are no motors sticking out at all angles, all motors/gears are
totally enclosed with just 2 cables connecting the motor housings to the electronics column. The
DEC motor housing does interfere with the RA motor housing when at the meridian, meaning
this mount cannot track across the meridian; if the object you are viewing passes over the
meridian the scope will stop and perform a meridian flip. Please note, the CGE is not alone in
this, most goto mounts will not track far past the meridian before performing a flip. This has never
been a problem to me because I am aware of it and if I am imaging I make sure my target is few
degrees either side of the meridian before proceeding.
The motor cables are short, do not tangle and are fitted with RJ45 quick release connectors for
ease of set up / take down. Easy that is until nights with sub zero temperatures when fingers are
cold and plug shrouds are solid, making release difficult and fiddly. Again not a problem on
permanent set ups. Just one point on the RJ45 connectors, they are delicate and can cause
problems with the mount if they are damaged, I had an intermittent fault on the RA lead which
was down to a faulty shield connection. New leads are cheap and easy to come by, just Google
for screened RJ45 patch leads to find replacements, (Note! unscreened lea ds will not work).
Secondly, and to some more importantly, there are no setting circles or manual slow motion
controls at all. In fact the mount is devoid of scales and graduations of any kind except for a small
RA shaft altitude scale for polar alignment. This mount is a computerized mount only and it
shows.
The counterweight shaft screws into the end of the mount dec’ shaft and takes the 1 or 2
Celestron weights for whichever scope you fit. The shaft is a hefty 1 1/4” diameter with a butch
look and feel to it. No bendy ¾” shafts here to wobble about.
Finish on the mount is matt black type crackle paint on motor housings and black anodizing with
bronzed gold highlights in other areas, this colour scheme makes for a very striking effect and
looks a treat with the colour coordinated scope perched on top. The crackle finish has proven to
be a little fragile and will chip easily, a can of Halfords Matt Black paint comes in handy for
touching up the inevitable chips.
RA Altitude adjustment is via a socket headed screwed rod through the base of mount which can
be adjusted from the North and South end. Once polar alignment is achieved the altitude can be
locked with 2 socket head grub screws, this is important because if not tightened there can be a
noticeable shift in the alignment with scope position.
RA Azimuth adjustment can be achieved by slackening 2 plastic headed hand knobs and rotating
the head, a small socket headed adjusting screw is provided for this purpose but so far I have
never needed to use the screw, it being easier to push the head around by hand for alignment, (1
less tool to use).
There is no integral polar alignment scope included with the mount, instead you have to sight
along the top of the RA axis to rough align. Then once you have switched on and performed an
initial 2 star alignment, a Polar Align routine can be performed which points the scope to where IT
thinks Polaris is, then you adjust the mount to bring Polaris into the eyepiece. This routine is quick
and easy and is good for visual and web cam planetary imaging but you really need to drift align
the mount to get an accurate polar alignment. An optional bolt-on polar alignment scope can be
purchased separately to get a good rough alignment but you will still need to run the Polar
Alignment and drift align routine for accurate alignment.
Each axis has 2 large anodized aluminium lock knobs/clutch levers, (latest models have 4 per
axis). Both knobs on each axis need to be tightened fully during set up, to ensure the axis is
clamped securely. The knobs are big and easily manageable to the gloved hand. Once these
knobs are tightened on set up you don’t touch them again until take down.
The scope dovetail on the Dec axis is in-keeping with the rest of the mount in that it is BIG. The
dovetail takes the large Losmandy/Celestron dovetail and firmly clamps this with 2 very large
anodized and knurled lock screws, again easily operated with gloved hands. Please note! The
CGE dovetail bar is 3” and is slightly narrower than the Losmandy bar, not a problem on the CGE
clamp as it will take this difference but beware on other mounts.
Electronics Column
The mount fits on to a black crackle finish aluminium electronics
column or Pier as Celestron call it, I prefer to call it a column as
pier brings to mind a tripod free scope and the mount definitely has
a tripod.
This Column houses most of the electronics for the scope, it also
acts as a large junction box for the Hand Box, mount cables,
power cable, guider and PC connections. The column internals
proved to be a little fragile and can cause problems. The rear of the sockets for the external
connections are connected to the main circuit board using multi pin connectors and flying leads.
These connectors are not of the highest quality and can come loose with normal handling. The
same connectors are used in the shaft motor housings and can cause problems there also.
The Column fits snuggly onto the tripod with 3 off 3/8” UNC socket head screws and the mount
head in turn fits onto the top of the Column in a similar manner.
Using the power lead supplied you can either connect the column to your car battery via the cigar
lighter or run it from a power pack. This mount is not too power hungry but still requires a good 12
volt DC 1.5 amp supply. Do not use a regulated 13.8V power supply, this will void your guarantee
with Celestron.
The Hand Box is basically Nexstar loaded with the CGE Firmware. The buttons are big and do
not need 2 or 3 presses like other manufacturers and the big LCD display is clear and easy to
read with a red adjustable backlight and contrast. My first hand box display died permanently on
the first day but was quickly replaced by the dealer, This is not too uncommon a fault with these
hand boxes and is not just a CGE problem. Just a note here, in very cold conditions the display
may fade and sometimes disappear altogether, don’t worry, stick the hand box in your jacket to
warm it up a little and the display will soon return.
Not a lot more can be said of the column for the moment, it does its job and that’s all but please
note you WILL need tools to put this mount together, 2 Imperial AF Allen Keys are supplied and
these are sufficient for basic set up and take down, (all screw threads on this mount are imperial
UNC). ADM in the states can supply a range of hand knobs which replace the 3/8” allen head
screws and makes set up virtually tool free.
Tripod
What a beast! Again in-keeping with the look and feel of the mount the tripod is big. At minimum
extension the tripod top sits at 34”, add to that the height of the column and mount and you only
need to extend the legs by a few inches to have the scope at a manageable height, which makes
for a very steady platform.
The stability of the tripod is further enhanced with a heavy duty plastic Spreader which tightens
up on a screwed rod to firmly hold the tripod legs and stop torque twist of the head and mount. A
smaller hinged spreader bar at the base of the top legs is fitted as a stay to prevent the legs from
being spread too far.
A nice touch to the tripod is a captive strap around the base of the legs which can be used to tie
the legs together when transporting.
Switch On and Operation
When you first switch on, the mount needs to run to its home position with the scope pointing
North. Each axis is fitted with micro switches for this position, so after pressing “Enter” twice the
mount runs each axis until these switches operate.
Once the switch positions are found the scope knows where it’s pointing and you may enter the
time, time zone, date and grid co ordinates for your site which are all stored within memory and
do not have to be entered again unless you take the scope to another site. The internal clock is a
nice touch and means you do not have to enter the time and date every time you switch on.
The mount can now be aligned ready for the Goto function. A basic 2 star alignment using the
default alignment stars will give semi reasonable Goto accuracy but if you want to get the object
in the field of view every time a 2 star align on one side of the meridian with up to 4 calibration
stars the other side of the meridian is easy and improves the accuracy tremendously. Alignment
and calibration stars may be changed at anytime in the observing session to maintain the mounts
accuracy but personally I have never need this even on an all nighter.
If ordinary Goto is not accurate enough, say when you are using a CCD for imaging, the mount
has a Precision Goto routine which points to a star nearby the object you require. Centering the
star in the eyepiece and pressing Enter will then slew the scope to accurately place the object
bang on to the CCD chip. There is also a Sync function that can be used to improve pointing even
more, but you won’t need it J
There is a Solar System align routine which is useful for daytime observation of the planets.
It’s worth a mention here that before the advent of the new flash upgradeable hand boxes
pointing accuracy was a little hit and miss as alignment relied on a maximum of 3 stars. Some
mounts would place the object in the centre of the FOV of a 20mm eyepiece reliably every time
from the normal alignment routine whereas other mounts will require more care and attention
during alignment. I actually had 2 mounts, the first when it worked, was deadly accurate with a
basic 3 star alignment but during the course of trying to trace a fault, (faulty RA lead), the mount
got swapped and unfortunately the replacement required a bit more care when setting up, but
that’s no problem now because I have the flash upgradeable hand box.
As for what objects to point the mount at, well the Hand Box is loaded with them, the lists include:
Messier
NGC
IC
Caldwell
Solar System
Named Stars
SAO Catalogue
To further assist location these catalogues are broken down into the following easy access
menus:
Named Stars
Named Objects
Double Stars
Variable Stars
Asterisms
CCD Objects
IC Objects
Abel Objects
Constellations
The constellations selection is particularly useful, here the mount will guide you through the
interesting objects within a chosen constellation.
Information about any object the scope is pointed to is available at the press of a button and the
Tour of the nights best objects is always a worthwhile exercise.
The mount can be PEC Trained for more accurate unguided tracking and also connected direct to
an ST4 type auto guider. I have not used the PEC function because I autoguide but I understand
from others that it works and works well. I autoguide the mount and find it easy and a joy to use. I
normally guide through the PC port on the column using Guide Master software as described in
my Rough Guide to Autoguiding.
One final point, the mounts are usually shipped with a copy of Nexremote and a selection of PC
leads including a USB to Serial adapter. This allows you to run the mount direct off a laptop,
either through the handbox or without by connecting direct to the PC port. This is a powerful piece
of kit and enables the mount to be run direct from a PC using most planetarium software
packages. More importantly Nexremote allows the use of a wireless gamepad for basic mount
controls. Is that Cool or what?
Conclusion
As stated at the outset, this is a warts and all review but please do not misinterpret the warts as
dissatisfaction with this mount. Far from it, I am impressed with this mount and do not regret my
choice. Experience since the early teething problems have more than made up for its faults; faults
which I must add are mainly down to quality control issues which I hope Celestron have
addressed now their future appears to be a little more secure.
Due to its size it will take anything up to and possibly past a 14” SCT with ease and will take the
weight of all but the heaviest of accessories.
Tracking accuracy is second only to other high end mounts with a very low PE attributable to
accurately machined phosphor bronze worm and wheels.
If you are thinking of investing in a high end, heavy duty GEM mount then the CGE is well worth
considering, please do not let the warts mentioned in this review put you off. The warts are minor
points only and are soon sorted if you are unfortunate enough to experience them. There are
plenty of CGE owners out there who have never had a single problem with the mount but it is
always better to know of any possible problems with a piece of kit before taking the plunge and
investing your hard earned cash.
Thanks for looking and clear skies
Phil