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Celestron CG4 mount.

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#1 Binojunky

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Posted 11 October 2011 - 08:50 AM

Hi, would anyone out there know what these mounts can handle weight wise?, many thanks Dave.PS it has the tubular steel tripod. :help:

#2 terry59

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Posted 11 October 2011 - 08:56 AM

They are touted for 20 lbs. I've been imaging with mine carrying 10.6 lbs and had no issues

#3 BarrySimon615

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Posted 11 October 2011 - 09:25 AM

Look at my "Little White Bull" thread about the CG4. I agree that it is very capable. As said it is specified that it will handle up to 20 lbs. The loads that I have had on it probably max out at 10 lbs. (Wegat/Meade modified ETX 125 with "Ken Dauzat) tube ring and mounting dovetail with 2" diagonal and heavy 2" eyepiece.) That tube is short so moment arm effect is minimal. It seems to be about perfect for this mount.

The mount head is not crippled by an inferior and shakey tripod, the steel tripod complements the head. Still and all I would not feel that a telescope with a long moment arm (6" f/8 achromat as an example) and a payload approaching 20 lbs would be optimally mounted. A C8 tube might be ok, an ED 100 or SP C102 tube assembly would be fine.

I have in past years used my 6"f/5 Jaegers refractor on my Super Polaris mount and even done some photography with it with decent guided exposures, but in light or no wind only and with the 9x60 finder removed (dovetail attachment). That 23 lb. payload was somewhat beyond the specified limit of the SP, but it worked, but it was not optimal. Personally I think the SP has more payload capacity than the CG4, so my personal payload capacity for the CG4 would be about 15 to 16 lbs. photographically and about the stated 20 lbs. visually as long as tube length is relatively short as you approach these weights (less than about 3 feet).

The CG4 does come as a package with the Celestron XLT Omni scopes and the longest of these, the 120mm refractor is 40 inches long, but the weight is about 12 lbs. Heavier telescopes of this length, say approaching, but still under 20 lbs, would be undermounted. So as you approach a 20 lb. payload, tube length has to come down to avoid problems.

Barry Simon

#4 Binojunky

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Posted 11 October 2011 - 09:40 AM

Thanks gentlemen, I had it in mind to plonk a 4" f11 refractor on it, weight about 12lbs, however one has to take into account the tube length and leverage effect, also to get the eyepiece at a convenient height it would have to be used with the legs extended pretty well to their max?, Dave.

#5 BarrySimon615

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Posted 11 October 2011 - 09:57 AM

Thanks gentlemen, I had it in mind to plonk a 4" f11 refractor on it, weight about 12lbs, however one has to take into account the tube length and leverage effect, also to get the eyepiece at a convenient height it would have to be used with the legs extended pretty well to their max?, Dave.


A 4" f/11 at 12 lbs would be ok. While it does have longish moment arm effect, the moderate weight would help offset the tube length. A lot really depends upon where the weight is concentrated, an overbuilt objective cell and a heavy focuser contributes greatly to the moment arm effect.

Regarding the tripod height with a long tube - the tripod does not extend too much and I found it to be fine fully extended. With my 3" f/18.4 refractor on the mount (tube length from the end of the diagonal at focused position to the end of the dew shield is a rather long 62 inches) and the focuser end does sit lower than I would like. I have considered getting a half pier for the mount, however I do have other mounting options for this tube assembly and the CG4 is a good height for other scopes that I will be using with it - Wegat/Meade ETX, Stellarvue 80/9D, University 80 f/6.25 with Coronado H-Alpha SolarMax 60 filters.

The other night the long refractor focuser placement worked out very well with me either on my knees or in a chair, so I think in your case the 4" f/11 may work out very well even without a half pier.

Barry Simon

#6 Binojunky

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Posted 12 October 2011 - 12:01 AM

Thanks Barry, thinking of getting the 4"f11 refractor sold by Canadian telescopes also sold by Hands On Optics, sheesh I need another 4" like a hole in the head,it reminds me of a Edmund I had many years ago, we will see, Dave.

#7 Talstarone

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Posted 12 October 2011 - 01:31 PM

I have owned two different CG-4 EQ mounts.For the price I was very well pleased with the performance.

I believe you will make a very good price to performance choice with this mount(also there are many aftermarket parts for this mount that it can keep up with the times).

#8 terry59

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Posted 12 October 2011 - 04:15 PM

I have owned two different CG-4 EQ mounts.For the price I was very well pleased with the performance.

I believe you will make a very good price to performance choice with this mount(also there are many aftermarket
parts for this mount that it can keep up with the times).


Can you provide a place/places please?

#9 o1d_dude

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Posted 12 October 2011 - 11:09 PM

Thanks Barry, thinking of getting the 4"f11 refractor sold by Canadian telescopes also sold by Hands On Optics, sheesh I need another 4" like a hole in the head,it reminds me of a Edmund I had many years ago, we will see, Dave.


I have one of four StellarVue prototypes of the Hands On scope and I have a modified Celestron CG-4. By modified, I mean the CG-4 has the much sturdier CG-5 tripod and the Orion tall pier. The combined weight of the tripod and pier work wonders in providing stability.

I have no complaints with the CG-4 EQ head other than it being a "dumb" mount as opposed to computer-controllable.

#10 beatlejuice

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Posted 14 October 2011 - 12:45 AM

Ditto on the stability with the Orion pier and the legs retracted.

Eric

#11 t.r.

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Posted 14 October 2011 - 07:13 AM

What was the sale price of these awhile back...$150?

#12 94bamf

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Posted 14 October 2011 - 07:55 AM

I guess it depends on your tolerance for shakes, but personally owing both the Astro telescopes 4" F/11 refractor and a newer white CG4 mount, I do not think they work well together at all. I ride mine on a Sky View Pro GEM now, which seems about the smallest mount that will handle a scope that long without excessive shaking while trying to focus. I do run the Orion extension on the SVP. I thought the CG4 did well for shorter scopes, it worked ok for my C102HD F/10 refractor which is much lighter than the AT 102 F/11, but was about at my limit even with that scope.. YMMV..

Ken

#13 Binojunky

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Posted 14 October 2011 - 09:22 AM

Thanks Ken, thats what I had planned to put on it, no point if its going to jiggle , I will revise my plans to use a lighter shorter scope ,possibly my 5" Mak, Dave.

#14 Talstarone

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Posted 15 October 2011 - 02:22 PM

JMI makes wonderful products for this mount,as well as most mounts and scopes on the market.
www.jmitelescopes.com

Also Orion and companies like Astronomics carry motor drives,vibration pads,and many other useful accessories for a CG-4(or Astroview)

#15 CrazyPanda

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Posted 21 July 2014 - 11:22 PM

Just want to throw my two cents in. I know this is an older thread, but info is info for those who are seeking it!

The CG4 does come as a package with the Celestron XLT Omni scopes and the longest of these, the 120mm refractor is 40 inches long, but the weight is about 12 lbs. Heavier telescopes of this length, say approaching, but still under 20 lbs, would be undermounted. So as you approach a 20 lb. payload, tube length has to come down to avoid problems.

Barry Simon


I own the 120mm Omni XLT and it is attrocious. The scope is perfectly capable, but even with the heavily cleaned and smoothed focuser modifications I did, merely touching the focuser sends the telescope into uncontrolled vibrations, and that's with a simple 19mm Panoptic AND without the tripod legs extended.

The CG4 looks and feels MUCH, MUCH more sturdy than it actually is. I would estimate its true weight capacity at closer to 5-6 pounds, and even then you better have a feather touch or motorized focuser and an eyepiece with huge eye relief.

Also, the tension locks that keep the mount locked in place wear out very quickly, even when the scope is properly balanced on all axes.

Overall I'm quite disappointed with the performance of the CG4. Would not recommend the OmniXLT series to anyone because of it.

#16 beatlejuice

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Posted 22 July 2014 - 03:08 AM

Just want to throw my two cents in. I know this is an older thread, but info is info for those who are seeking it!

The CG4 does come as a package with the Celestron XLT Omni scopes and the longest of these, the 120mm refractor is 40 inches long, but the weight is about 12 lbs. Heavier telescopes of this length, say approaching, but still under 20 lbs, would be undermounted. So as you approach a 20 lb. payload, tube length has to come down to avoid problems.

Barry Simon


I own the 120mm Omni XLT and it is attrocious. The scope is perfectly capable, but even with the heavily cleaned and smoothed focuser modifications I did, merely touching the focuser sends the telescope into uncontrolled vibrations, and that's with a simple 19mm Panoptic AND without the tripod legs extended.

The CG4 looks and feels MUCH, MUCH more sturdy than it actually is. I would estimate its true weight capacity at closer to 5-6 pounds, and even then you better have a feather touch or motorized focuser and an eyepiece with huge eye relief.

Also, the tension locks that keep the mount locked in place wear out very quickly, even when the scope is properly balanced on all axes.

Overall I'm quite disappointed with the performance of the CG4. Would not recommend the OmniXLT series to anyone because of it.


Sure glad I bought mine before I read this :grin:
Sorry about your bad experience.

Eric

#17 karstenkoch

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Posted 22 July 2014 - 04:39 AM

I recently took delivery of a CG-4. Have used it with 72mm and 80mm refractors so far. Not terribly taxing, I know, but with those refractors focusing and slo-mo slewing have both been rock solid. Mounted my 102mm on it, but haven't viewed with that setup yet. But, it still feels solid with the 102mm. Very happy with the CG-4 so far. Only time will tell in the long run...

#18 Geo.

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Posted 22 July 2014 - 07:42 AM

I've always wondered why this mount, the EQ-3M or the Orion AstroView have a place in the market with so many CG-5s and Vixen Polarii available for about $200. It helps to really snug up the leg to hub hinge bolts and to fit the tray.

#19 Sarkikos

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Posted 22 July 2014 - 08:22 AM

I have both mounts. The CG5 is appreciably heavier and more cumbersome than the CG4. I preferred my C4-R (C102GT) on the CG4 rather than the CG5. But I did replace the legs on the CG4 with wooden ones from Hands On.

Mike

#20 Rachal

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Posted 22 July 2014 - 12:25 PM

Mike, how much did the wooden tripod help with vibrations; I always thought the metal tripod that came with the CG-4 looked pretty substantial?

#21 Joe Bergeron

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Posted 22 July 2014 - 01:07 PM

I had a CG-4 for a while. My impression is that it's a tiny thing best suited to a short 3" refractor or smaller, or something like a C5. Its performance with the 6" f/5 reflector it came with was bearable but not impressive. It certainly was cute though.

#22 beatlejuice

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Posted 22 July 2014 - 01:22 PM

I must me missing something here. Or maybe I got a rare sample. Admittedly I added an Orion accufocus and mount extension, but it has always handled my 120 with ease.

Eric

#23 swix

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Posted 22 July 2014 - 03:30 PM

I have had the Omni 120 & CG4 mount ... sold the 120 and kept the CG4. I also had the Astrotelescopes 102 f/11 .. sold that also. I use the CG4 with a C6. Very acceptable performance and less vibration when focusing than the long refractors.. The mount is just not designed for a refractors length , IMO ..

#24 Sarkikos

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Posted 22 July 2014 - 04:01 PM

I don't like the tripods with rectangular aluminum legs, the ones that seem almost like extruded plastic. The wooden legs are better than those. If I could have taken all the tripods I had received over the years with those kind of aluminum legs and replaced them with sturdy wooden ones, I would have done it.

The thick tubular aluminum legs are also better than the rectangular ones, and the thick tubular steel are better than those.

It's kind of vague to say the "CG4" or the "CG5" because there have been several versions of each over the years, with different kinds of heads and different tripods.

Mike

#25 Sarkikos

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Posted 22 July 2014 - 04:33 PM

Thanks gentlemen, I had it in mind to plonk a 4" f11 refractor on it, weight about 12lbs, however one has to take into account the tube length and leverage effect, also to get the eyepiece at a convenient height it would have to be used with the legs extended pretty well to their max?, Dave.


My advice is to get a good chair and have a sit. Then you won't have to extend the legs as high. In general mounts tend to vibrate less if they are kept as low as possible.

On the other hand, long tube achromats like a 4" f/11 can have a big range in eyepiece elevation depending on whether the OTA is pointed near the horizon or zenith. The best compromise I've arrived at is to setup the mount so you can sit when the OTA is point near zenith.

But you'll probably have to stand when you look near the horizon. A chair that can accommodate both extremes for a long achro - without your having to stand sometime - might be heavy and awkward. At least they have been for me. A big heavy astro chair kind of defeats the purpose of these smaller apertures, which are best for grab-n-go.

Mike






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