rocco13
Carpal Tunnel
Reged: 07/29/06
Posts: 1535
Loc: Phoenix, Arizona
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I just picked up a Super C8, 1984 vintage (by my best educated guess). Optics are in great condition, and used it last night for a few hours and was very pleased with the views.
But in the daylight, there is a LOT of dust and other small flakes of who-knows-what on the primary and in the reflection of the secondary. I know I should probably leave it alone, but my question is how I would go about opening the tube up to clean up inside. Is it as simple as removing the corrector, or will I run into more issues later if I don't get it back on exactly as it came off? At first glance it looks simple enough...loosen the screws and make sure they go back in the same orientation when done, but is there an important step or procedure I'm overlooking?
Thanks in advance for any help on this.
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Rocco
Super C8 (1984 vintage)
Celestron 102 f/5
and a cheap pair of binoculars
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bdjeep
super member
Reged: 01/29/07
Posts: 178
Loc: Bolton, MA
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This should help.
It's relatively straightforward to remove the corrector. Just make sure you mark where everything goes back together.
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Arbacia
sage
Reged: 04/18/07
Posts: 382
Loc: Madrid, Spain
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mark the original position to place it as originally it was when done.
When the frontal ring that retain the Schmidt plate is removed, probably the schmidt plate stucks to the tube. Be careful, you can break the plate. Take your time. It will take some minutes (or half an hour in my C8 orange tube) to soften the attachment. Use a piece of cotton soaked in water or alcohol. Take your time. Grab the plate from the central secondary suport and twist carefully or use a toothpick to jack up the margin of the plate just enough to allow the watter or alcohol to run by capilarity into the stucked area. That is the worse part.
Keep the cork segments and place again if they are in goog condition (flexible). But if the small pieces are brittle replace them. I used small portions from the cork of a bottle of wine.
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LightBridge 12"
Celestron C8 (orange tube) on HEQ5
Set of Hyperion EPs; DMK 31AF03.AS
CN image gallery
http://www.asociacionhubble.org
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jonbosley
professor emeritus
Reged: 10/19/05
Posts: 540
Loc: Texas
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Another option is to send it to Celestron for a professional clean & alignment (there are other companies that do it but the ones I checked were twice as much). I got a used C11 and it was very dirty (white flakes on the inside) & a small scratch near the secondary, also I could not get a good star test. It looked like someone had removed the corrector at some point.I would not have thought it possible for a primary mirror to get that dusty in a closed system. I sent it to them (they take thier time)and just got it back its like a brand new scope, even the scratch was gone! Great star test and contrast, very pleased with the result.
Jon
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C11 XLT Celestron
Atlas Goto Mount on Concrete Pier
WO 66 SD Doublet APO Refractor
Philips SNC900NC Webcam
Faymax FC-1000m Webcam with cooling fan
Orion Star Shoot Deep-Space CCD
POD Observatory
www.whitedwarfobservatory.com
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Arbacia
sage
Reged: 04/18/07
Posts: 382
Loc: Madrid, Spain
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Jon
Just for curiosity, how much is that service in USA?
Patricio
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LightBridge 12"
Celestron C8 (orange tube) on HEQ5
Set of Hyperion EPs; DMK 31AF03.AS
CN image gallery
http://www.asociacionhubble.org
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jonbosley
professor emeritus
Reged: 10/19/05
Posts: 540
Loc: Texas
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Patricio,
For the C11 it was $250.
Jon
--------------------
C11 XLT Celestron
Atlas Goto Mount on Concrete Pier
WO 66 SD Doublet APO Refractor
Philips SNC900NC Webcam
Faymax FC-1000m Webcam with cooling fan
Orion Star Shoot Deep-Space CCD
POD Observatory
www.whitedwarfobservatory.com
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rocco13
Carpal Tunnel
Reged: 07/29/06
Posts: 1535
Loc: Phoenix, Arizona
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Thanks all for the responses.
I just emailed the nearest scope shop to me, down in Tucson, and he said they'll clean it, lube the focuser and baffle, star test and collimate, all for $150.
Knowing my mechanical shortcomings, (combined with my temper when things don't go right!), it seems well worth it. Now if I can just make time to drive down there again. (Wouldn't you know it...I was just down there last weekend!)
--------------------
Rocco
Super C8 (1984 vintage)
Celestron 102 f/5
and a cheap pair of binoculars
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jonbosley
professor emeritus
Reged: 10/19/05
Posts: 540
Loc: Texas
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I think that you made a wise choice Rocco. Good luck.
Jon
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C11 XLT Celestron
Atlas Goto Mount on Concrete Pier
WO 66 SD Doublet APO Refractor
Philips SNC900NC Webcam
Faymax FC-1000m Webcam with cooling fan
Orion Star Shoot Deep-Space CCD
POD Observatory
www.whitedwarfobservatory.com
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Al Canarelli
Carpal Tunnel
Reged: 12/06/07
Posts: 1531
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I've seen many good telescopes go down the tubes as a result of well intentioned owners who tried to clean them. If it ain't broke, don't fix it!
You just mentioned that you used it and wrote, "Optics are in great condition, and used it last night for a few hours and was very pleased with the views." Enjoy your new telescope!
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Arbacia
sage
Reged: 04/18/07
Posts: 382
Loc: Madrid, Spain
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Thanks, Jon. It was just to know.
--------------------
LightBridge 12"
Celestron C8 (orange tube) on HEQ5
Set of Hyperion EPs; DMK 31AF03.AS
CN image gallery
http://www.asociacionhubble.org
|
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