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Old C90 needs a kick

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#1 boyd

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Posted 26 March 2020 - 10:15 AM

I’m studying the back on my c90. It seems there is a screw in spacer that either holds the scope together or stops down the exit to .965. Can this piece be removed and replaced with something that accepts 1.25”?

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#2 Jeff Lee

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Posted 26 March 2020 - 10:49 AM

Yes, It's called a Large Accessory Ring. The one that fits the ETX (I think) also fits the C90. On Amazon: https://www.amazon.c...d/dp/B000EINJRO



#3 G-Tower

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Posted 26 March 2020 - 10:53 AM

I’m studying the back on my c90. It seems there is a screw in spacer that either holds the scope together or stops down the exit to .965. Can this piece be removed and replaced with something that accepts 1.25”?

I've tried removing one before to no avail....



#4 MCJ2087

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Posted 26 March 2020 - 11:19 AM

I’m studying the back on my c90. It seems there is a screw in spacer that either holds the scope together or stops down the exit to .965. Can this piece be removed and replaced with something that accepts 1.25”?

You may be referring to the backcell connection?  Try looking at this link:

 

https://www.cloudyni...nge-c90/page-14

 

That whole thread was interesting reading.


Edited by MCJ2087, 26 March 2020 - 01:35 PM.


#5 houndsbourgh

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Posted 26 March 2020 - 12:53 PM

I’m studying the back on my c90. It seems there is a screw in spacer that either holds the scope together or stops down the exit to .965. Can this piece be removed and replaced with something that accepts 1.25”?

 

No. The eyepiece holder helps support the reflector assembly in the back of the OTA. They were threaded into place and set with epoxy.Very hard to get out. Best bet as mentioned above is a Large Accessory Ring (LAR) and visual back. Here is the Celestron, 3D printed ABS and Meade ETX rings with the Celestron93653-A visual back. Also available is a direct .965 to 1.25" eyepiece adapter. Very simple to use but I takes away a lot of your back focus.

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Edited by houndsbourgh, 26 March 2020 - 12:58 PM.


#6 houndsbourgh

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Posted 26 March 2020 - 01:08 PM

Oh forgot to mention the .965 to 1.25" eyepiece adapter also constricts the view over the LAR and visual back combo. Some users have run into problems on wider field 1.25" eyepieces.




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