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Celestron selling the carbon fiber C11's anymore?

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#1 Jeff Smith

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Posted 26 March 2013 - 10:29 AM

I'm thinking about getting one if I can find one. Are they still making them anymore?

#2 jrbarnett

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Posted 26 March 2013 - 11:16 AM

Nope.

In fact, I think the regular C11's days are numbered. Celestron seems to be slowly winding down production of larger standard SCTs in favor of the Edge variants. Makes sense. The larger lower volume scopes are likely less price sensitive than the smaller high volume units.

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#3 JoeR

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Posted 27 March 2013 - 10:40 AM

If you're in Chicago area I'd advise against a CF OTA. It would take a ridiculously long time to cool down. Sometimes not at all. There is no noticeable difference in weight and the focus issue is also not apparent with the newer OTAs with their mirror locks.

#4 Footbag

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Posted 27 March 2013 - 11:11 AM

Nope.

In fact, I think the regular C11's days are numbered. Celestron seems to be slowly winding down production of larger standard SCTs in favor of the Edge variants. Makes sense. The larger lower volume scopes are likely less price sensitive than the smaller high volume units.

- Jim


I hadn't heard that, but as good as Edge HD 1100's look at $3300, it makes regular C11's that much more attractive for half the price. I may be wrong, but it seems like there would be a place for both OTA's. Then again, I don't have to make money off of this hobby.

#5 stevew

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Posted 27 March 2013 - 10:13 PM

It would take a ridiculously long time to cool down. Sometimes not at all.

I agree.
I had a C/F C9.25 and it would take hours, if it all.
Aluminum tube gives up it's heat much faster.

Steve

#6 Dan Finnerty

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Posted 27 March 2013 - 10:31 PM

I'm thinking about getting one if I can find one. Are they still making them anymore?


My experience with a carbon fiber ES 127ED is that it really dews up due the highly emissive black CF tube. I have noticed that anything black, such as nearby automobiles equally dew up first and most heavily. White/light colored vehicles produce substantialy less dew. So if dew is an issue where you observe, you will get a lot of moisture on a large C11 CF tube.

Also, you will likely want to add vent fans to the C11 even with the aluminum tube as it has a substantial thermal mass and you will get significant tube currents for two or more hours after setup depending on temperature differences and cooling rates. I just learned to leave the fans on for the entire observing session rather than fiddling with them. [I got the Deep Space Products TEMPEST fans, they installed easily, work well and look neat and clean].

The HD OTAs come with the vent holes, so adding fans is easy, just spend some $$$. I have heard that many of the non-edge OTAs are shipping with the vents now, but I have no personal experience.

#7 Jeff Smith

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Posted 28 March 2013 - 05:42 AM

I just wanted to confirm that they are not making them anymore. I ended up finding one used near me. I prefer the carbon fiber tubes...as long as they have a Temp-est system. Less cool down and more stable. I had one years ago with vents and loved it.

#8 PatHolland

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Posted 28 March 2013 - 05:50 AM

I like my C8 CF tube. I am able to image all night with drastic temperature shifts with no change in focus. (off axis guiding of course). It does tend to dew up (or frost - depending on temp) pretty good but I am fine with that. I have never been able to achieve this with non CF tubes with temp changes like that. I look forward to using my ES 127mm CF for the first time.

#9 mikertx

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Posted 29 March 2013 - 02:38 PM

I had the old CF Nexstar 11 then later when I moved to GEM mounts got a Al tube C11. I missed the stable focus and replaced my tube with a CF one from public missiles.

Mike

#10 EFT

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Posted 30 March 2013 - 02:30 PM

My understanding is that Celestron stopped making them due to a supply and cost issue. CF has become relatively expensive compared to aluminum. However, the focus stability for long-session AP was definitely a benefit. The slower cooling was problematic, but would be relieved by the new vented cell design of the EdgeHD. Perhaps the CF tubes will come back. Until then, you have to rely on modding the old CF OTAs or retrofitting the new ones with aftermarket tubes.

#11 Geo.

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Posted 30 March 2013 - 04:08 PM

I heard that Air Bus decided against composites for its new model as the anticipated drop in CF prices hasn't materialized.

#12 Billydee

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Posted 04 April 2013 - 03:43 PM

This company sells carbon fiber and I think they make a custom 11 inch.

http://www.astromart...ified_id=816367

Bill

#13 Jeff Smith

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Posted 04 April 2013 - 06:51 PM

They just sell the tube material. I found a gently used CF C11.






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