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C11 and sirius mount

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#1 Nick-Sydney

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Posted 18 March 2009 - 09:07 AM

Hi All,

Just wondering how you think a C11 will go on a sirius mount. The C11 plus accessories will weigh in around 16kg. The mount is rated at approx 18kg. Will this be ok for visual use? I don't want to find the mount isn't up to the task.

I'm not concerned about AP for now, and realise I would need an Atlas or better for decent AP performance.

Opinions or experience appreciated!

Thanks,
Nick.

#2 borix

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Posted 18 March 2009 - 09:08 AM

I thought the Atlas was rated at 18kg max. The Sirius about... well a few kg less anyway.

#3 Nick-Sydney

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Posted 18 March 2009 - 09:14 AM

Hmmm. I've seen a few different figures quoted, but I believe it is around the 18kg mark, but could be wrong. I believe the atlas is usually rated at 20-25kg.

#4 Trever

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Posted 18 March 2009 - 09:19 AM

I believe it would be fine since technically for visual use, the C11 can be used with a CG5 mount, which is rated less than a Sirius. It still may only be good for visual or webcam imaging though.

The Atlas I am sure would be well suited for it. My CGEM is rock solid for it and I think it is similar to the Atlas in some ways.

#5 Patrick

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Posted 18 March 2009 - 09:54 AM

Just wondering how you think a C11 will go on a sirius mount. The C11 plus accessories will weigh in around 16kg. The mount is rated at approx 18kg. Will this be ok for visual use? I don't want to find the mount isn't up to the task.




I believe it would be fine since technically for visual use, the C11 can be used with a CG5 mount, which is rated less than a Sirius.



The biggest thing about putting a load like a C11 on either the CG-5 or the Sirius mount will be dealing with the shakes when focusing. If you invest in an electronic focuser and anti-suppression pads then it probably won't bother you. Personally I wouldn't want more than a C9.25 on either mount.

For the record, the CG-5 weight rating is not less than the Sirius mount. Both are rated by Orion for 30 lbs. OPT rates the CG-5GT at 35 lbs and the Sirius mount at 30 lbs. I've owned both mounts and tend to think they are about equal.

Patrick

#6 jim molinari

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Posted 18 March 2009 - 10:43 AM

I am using my C11 on a Sirius mount and I find it quite adequate for visual work and use with a Mallincam. However, I have swapped the 1.75" tripod legs for 2" legs from my ASGT. I also use a six inch counter-weight bar extension allowing for balance with two 11 lb. counterweights. I always use vibration supression pads on concrete/asphalt and occasionally on other surfaces. The Sirius mount provides excellent tracking and GoTo capability ... I am very pleased with it. The mount seems to be of excellent quality and only adjustment required was minor/additional alignment of the polar scope. I have upgraded the firmware to V3.24.
Jim

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#7 Luigi

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Posted 18 March 2009 - 12:06 PM

2" legs, and keep em short rather than fully extended. Also, that long vixen style dovetail can add a lot of flex. Getting a stiffer one or backing it up will help quite a bit. :jump:

#8 bbasiaga

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Posted 18 March 2009 - 05:26 PM

C11 on my atlas is pretty darn solid. Do you already have the mount or OTA? Depending on how you look at it, the kit from Orion with the C11 on the Altas mount knocks a boatload of money off the cost of the OTA or mount.

=Brian

#9 Zebra24601

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Posted 18 March 2009 - 07:27 PM

My Sirius is sitting on the 2" CG5 tripod. Not sure about the official weight rating. The CG5 might even be rated higher.

However, the Sirius is definitely a heavier mount. It moves the C11 around quietly and efficiently.

I usually don't extend the legs fully for the simple reason that, if I did, the C11 would sit so high that the eyepiece (with diagonal) becomes difficult to use, and the right angle finder would sometimes be even higher than that. It's also easier for me to handle the C11 if it's being attached to a mount at about belly button height instead of shoulder height.

The counterweight extension idea would not necessarily be a bad one. The Sirius has an extremely short counterweight bar. Because of that, I need to use 40 pounds of counterweights to balance my 30 pounds of telescope and accessories. Still, as I said, the mount drives the C11 quietly, quickly and efficiently.

#10 Lane

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Posted 18 March 2009 - 11:21 PM

My experience is that the standard sirius mount is to shakey even with the C9.25 on board. Vibration pads help but don't solve the problem. I would not use anything bigger than the C8 on the standard sirius mount. Now if you change the legs to the 2" variety and replace the saddle and the counterweight bar, then you might be ok. But of course if you do all that you will spend more than just buying a cgem. So my suggestion is if you want to haul the heavy stuff, get the atlas or cgem and then you don't have to modify anything.

#11 Trever

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Posted 19 March 2009 - 12:09 AM

For the record, the CG-5 weight rating is not less than the Sirius mount. Both are rated by Orion for 30 lbs. OPT rates the CG-5GT at 35 lbs and the Sirius mount at 30 lbs. I've owned both mounts and tend to think they are about equal.


My mistake. I thought the Sirius, being a bit better than the SVP, would be a bit better than the CG5. Sorry about that.

#12 Nick-Sydney

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Posted 19 March 2009 - 09:04 AM

Thanks for all the replies. They are much appreciated. I am getting the C11 and will try it out on my HEQ5Pro. It sounds like the mount might do the trick!

It will have a losmandy saddle plate I believe, a moonlight with motofocuser, and I will keep the legs shortened as suggested. I may also get the vibration pads and CW bar extension too. It sounds like 2" legs will really do the trick, so I'll keep an eye out for some 2nd hand legs which occasionally pop up fairly cheap.

Thanks for that photo and comments Jim - that has really eased my concerns to actually see a C11 atop a HEQ5...
I'm getting excited now :-))

I have to wait for it to be shipped down from Brisbane. I bought it from AlexN. :jump:

#13 AlexN

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Posted 19 March 2009 - 11:37 PM

I sure hope you enjoy it as much as I have Nick!! It will be sad to see it go in a way.. As I really love the all out light sucking power of the C11.. Just that imaging has forced me yet again to spend more money! :D

#14 stevew

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Posted 20 March 2009 - 12:03 AM

I used to own a Sirius mount, and used it with a C9.25.
It worked very well. Quite solid for visual observations, however, I also upgraded to the two inch legs.

Steve

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