What are you doing, Celestron??

[emadmoussa]

There's almost a majority opinion that the CG-5 mount Celestron supplies with their C11 XLT telescope is not enough to support this scope. I have this mount and it's still packed away. I don't really have the heart to use it with the C11 even though I'm sorely tempted. I am almost certain it'll wobble. But again, at first look, this mount even though looking similar to the Skywatcher EQ5 it has a 2" tripod and more support, which in principle should handle the C11.

I looked around the web, it seems a lot of people are happy with the combination: C11 and CG-5. I didn't see much complain about the telescope being under-mounted. You'd think...well, visually it might handle the C11, but when it comes to imaging look elsewhere. But I've seen posts praising this mount as an imaging rig. What's going on here?

If Celestron confidently supplies this mount with their C11, wouldn't they know better? Don't they have a valid evidence it works just fine?? Or, are we all just scared to take our chances with the CG5 and C11 package?!

[michael.h.f.wilkinson]

That image does look like somebody put the mount on a very different tripod (pillar more likely). Inside an observatory, wind does not shake the scope, so that also helps. Finally, people might put up with dropping lots of subs, simply because they cannot afford a better mount. Even a wobbly mount could be considered better than no mount at all.

I do feel the above set-up may require carefully trapping all mice in the area in case they sneeze and cause a sufficient vibration to ruin yet another sub.

[Grotemobile]

This is what i have done to my mount

to solve the wobbly problem.The main

problem is the saddle.It is not up to

it with, the C11.The C9.25,is about the

limit for this scope.

http://www.firstlightoptics.com/dovetail-bars.html

Steve.

[Zakalwe]

My C11 is wobbly on an EQ6. its fine for planetary and visual, bout I don't think I'll be trying DSO imaging anytime soon.

As to the picture in the OP...no focal reducer so the owner is imaging at f10 and 2800mm I hope he's imaging Lunar stuuf, otherwise I'd like to see the results!!!

[LeeB]

Its strange how high the weight rating is on the cq5, I use mine with a 120mm refractor and initially it was a little wobbly so stripped it , carefully set it up and its rock solid,. I have even used the 10" orion newt on it and its fine for visual if you can cope with a little flex.. The big tripod definately helps over the eq5. I am in the process of fitting a belt drive system to it as and using it as my grab and go.

[emadmoussa]

My C11 is wobbly on an EQ6. its fine for planetary and visual, bout I don't think I'll be trying DSO imaging anytime soon.

As to the picture in the OP...no focal reducer so the owner is imaging at f10 and 2800mm I hope he's imaging Lunar stuuf, otherwise I'd like to see the results!!!

My TS refractor is almost the same weight as the C11, but with the NEQ6 on pillar it barley wobbles...Haven't tried the C11 on NEQ6 yet as it's away for repairs

[michael.h.f.wilkinson]

My TS refractor is almost the same weight as the C11, but with the NEQ6 on pillar it barley wobbles...Haven't tried the C11 on NEQ6 yet as it's away for repairs

It is not just weight that matters. Focal length is another issue.

[emadmoussa]

It is not just weight that matters. Focal length is another issue.

I would think the mount will wobble more with a longer telescope...?

[emadmoussa]

Oh, since we're on it...

I'm quite impressed by the build quality of the Celestron C11...However, the diagonal is quite sucky and looks cheap. I'm thinking about removing it and attach a 2" diagonal. Thoughts?

[Pig]

I did see the C11 on a couple of different mounts at the astromomy show and they all wobbled when I applied a slight flick to the counter weights

Im not sure what effect strong wind would have !!!!!

I did not see an EQ6 with any larger scope than 8" SCT and, as expected, this didnt move when I flicked it

However, the fork mounted 11 & 925 SCT's were rock solid as expected, they even stood firm during that unexpected earthquake ( forgive the smugness )

[emadmoussa]

I see your point, Shaun. However, I've got a fluctuating number of telescopes and usually don't like to have more than one mount. If a fork mount, then I'm stuck with it and wont' work for other types of scopes. NEQ6 will work with all I guess...if it ever comes back

[Pig]

Oh, since we're on it...

I'm quite impressed by the build quality of the Celestron C11...However, the diagonal is quite sucky and looks cheap. I'm thinking about removing it and attach a 2" diagonal. Thoughts?

Its all the 2" eyepieces you need to buy to go with it that put me off a tad

[michael.h.f.wilkinson]

I would think the mount will wobble more with a longer telescope...?

The long focal length means vibrations are magnified more. By contrast, the compact build of the C11 helps a lot. The CG5 mount would certainly collapse with a 2.8 m long OTA

[michael.h.f.wilkinson]

Oh, since we're on it...

I'm quite impressed by the build quality of the Celestron C11...However, the diagonal is quite sucky and looks cheap. I'm thinking about removing it and attach a 2" diagonal. Thoughts?

I used a William Optics Carbon Fibre Dielectric 2" Diagonal, and that worked very well (I used a push-fit one, because I already had a 2" visual back). Even with 1.25" EPs the increase in quality was evident (most severe errors in the figure of a mirror are at the edges, so bigger surface meant larger flat centre area). I now have a Denkmeier Filter-Switch Diagonal, which is ideal.

[emadmoussa]

The long focal length means vibrations are magnified more. By contrast, the compact build of the C11 helps a lot. The CG5 mount would certainly collapse with a 2.8 m long OTA

Can you imagine 2.8 m long OTA in the living room...

[Zakalwe]

Oh, since we're on it...

I'm quite impressed by the build quality of the Celestron C11...However, the diagonal is quite sucky and looks cheap. I'm thinking about removing it and attach a 2" diagonal. Thoughts?

If you're interested I have an Opticstar 2" SCT diagonal sitting in a drawer doing nothing. It's never been taken out of the box!

http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_212

[emadmoussa]

If you're interested I have an Opticstar 2" SCT diagonal sitting in a drawer doing nothing. It's never been taken out of the box!

http://www.opticstar.com/Run/Astronomy/Astro-Accessories-Telescopes-Opticstar.asp?p=0_10_5_1_8_212

Thanks! But I have a couple..

[Vince1963]

My C11 is wobbly on an EQ6. its fine for planetary and visual, bout I don't think I'll be trying DSO imaging anytime soon.

As to the picture in the OP...no focal reducer so the owner is imaging at f10 and 2800mm I hope he's imaging Lunar stuuf, otherwise I'd like to see the results!!!

I have the CG-5 & C11 combo... and after hearing all the negative stuff was considering the EQ6.. Not so sure now which way to go with it, Maybe best sticking to what i've got. Or is the NEQ6 much better?

[ollypenrice]

Celestron also sell the C14 on the CGE Pro mount. Do we really need to comment on this?

http://www.celestron.com/astronomy/celestron-cge-pro-1400-fastar.html

Olly

[davew]

Although I'm not too sure about the seriousness of this thread The images of the guy who has the Scope and mount in the picture don't look too bad to me.

Named Don Golka and living in Canada I think,

Dave.

[Live_Steam_Mad]

I use the CG-5 ASGT with stock 2" legs tripod and my C11 SCT (non-Edge), the only "modification" has been that I added a ScopeStuff 6" counterweight extension bar (screws into my original counterweight bar with M12 thread). Pictures ;-

https://plus.google.com/photos/101932667412801910198/albums/6051993476024595153?banner=pwa

Mine is a very late model Celestron CG-5 ASGT. It works great with the C11 SCT, mine is on a Losmandy D series dovetail (my C11 is an ex-CG11) with a Vixen style dovetail bolted to it by the previous owner. Vibrations seem to damp in about the same time as they did before when I was using the same weights (plus a heavy bike cable lock wrapped around the black weight to almost balance properly but not quite) except that now I can properly balance the C11 and heavy 2" diagonal and heavy 2" eyepieces and 9x50mm finder easily with room to spare at the end of the counterweight extension shaft, even though I am using only three weights, of 5Kg, 3.4Kg, and 1.8Kg. I do NOT need the 3 (or 4) x 5Kg weights that others need when using the original counterweight shaft. So now there is less weight to carry for me and the mount.

Tracking with this combination of CG-5 and C11 is superb at 700x magnification, no vibrations, and it has same tracking noise and volume as my friend's LX90 8". When it comes to using my C11 I am using pure visual, no imaging. I only dabble with imaging with my Meade 7" Mak with 0.5x reducer on the same mount, I never tried imaging anything with the C11 yet, and have no plans to. Vibrations take just a little while to damp with this CG5 / C11 combo, but not as long as I expected, at around 2 seconds after hand focussing at 700x. Still not bad at all, and can even be used in a breeze (if I remove my long cardboard dew shield that I normally use on the C11). Note the 11" Dew-Not brand heater strip in the photo, which is very efficient (18Watts i.e. 1.5A at 12V, being all it consumes) and works great. Even when I have left the 'scope outside for an hour to cool the primary mirror down (necessary in Autumn in NW England, it is cool outside at night at roughly 7 Celcius) to negate the thermal plume that I see from the primary at high magnifications, with cover off the corrector whilst forgetting to power the dew heater, and come out to the 'scope only to find it dewed over quite heavily, I find that when I put on the long cardboard dew shield and then power the dew heater at full power, it only takes a mere 10 minutes or so for the corrector to become clear. I'm very pleased with it. I power it via a separate PSU from the 'scope (to prevent odd operation of the CG5 due to switching spikes etc) of 12V 7A which cost me 22 GBP, and has 12.3V output (I use an identical PSU for my CG5).

The dew controller I use is a BCF / AstroEngineering 4 output single channel unit with 0-Vcc PWM variable output, and with 0-10V fan power variable output also (can be used with my 7" Mak's fan but I really need a Lymax type fan for the C11. I like the red light on the controller that shows the PWM duty cycle amount (flashes on for part of the power cycle by a variable amount). Works great and the dew controller does not get hot. The red tape on the counterweight shaft is for the fast, repeatable positioning of my counterweights. I only need to balance it once, then add tape, then next time I only have to position the weights against the tape and it's all ready to use. I have drawn 3 black circles with a bullet tip felt pen around the bottoms of the legs on the paving slabs of the patio for the same reason (accurate repositioning of tripod). Tripod only has to be levelled on the 1st night. ASPA gets me polar aligned on the 1st night and then I'm all set for future use with a minimum of hassle (I am already balanced in both axes - since I also added a piece of tape to the dovetail so that it acts as a marker to ensure I am always balanced - and polar aligned, and tripod levelled) so all I have to do is assemble it which is a 15 to 20 minute task at a leisurely pace. I am in a limiting magnitude 4.3 sky so not very good conditions. So I need as much aperture as I can get.

Yes the reason I use the CG-5 is because it was the most mount I could afford. I didn't really expect it to be able to cope with my C11 so well, I rather thought I would only get to use the 7" Mak on it. BTW I removed the cast iron 3.5Kg weight out of my 7" Mak so it's about 8.5Kg now with tube rings.

Best Regards,

Alistair G.

[michael.h.f.wilkinson]

As said many times before, a mount like the CG5, EQ5, or even the venerable Vixen GP will not collapse under the weight of the C11, but wobble will increase. Some still find it acceptible, others get seriously annoyed. One thing to watch with an undermounted scope is to use EPs with sufficient eye relief. If eye relief is a tad short, you keep nudging the rear of the EP with your brow/glasses, and the wobble never damps out.