#1  
Old 24-08-2020, 02:08 PM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Celestron diagonal question

Can anyone tell me if the telescope side of the Celestron diagonal can be unscrewed (the bit that screws to the visual back and to the triangular diagonal)?
Reply With Quote
  #2  
Old 24-08-2020, 02:26 PM
Sunfish's Avatar
Sunfish (Ray)
Registered User

Sunfish is offline
 
Join Date: Mar 2018
Location: Wollongong
Posts: 1,164
My very old Celestron diagonal is one piece but my Baader comes apart . It is fairly clear I think. Maybe post an image.
Reply With Quote
  #3  
Old 24-08-2020, 02:49 PM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Quote:
Originally Posted by Sunfish View Post
My very old Celestron diagonal is one piece but my Baader comes apart . It is fairly clear I think. Maybe post an image.

There's a photo to the link in the message. There is a crisscross pattern on it. Makes me think it's removable.


Edit: Not sure what happened to the link. Here it is again:


https://www.opticscentral.com.au/cel...U#.X0NVNTURU-U
Reply With Quote
  #4  
Old 24-08-2020, 05:43 PM
Merlin66's Avatar
Merlin66 (Ken)
Spectroscopy Wizard

Merlin66 is offline
 
Join Date: Oct 2005
Location: St Leonards, Vic
Posts: 7,850
Phil,
The standard SCT diagonal will fit the rear thread of the SCT.
The knurled floating ring is not removable, just ther to fit the SCT thread.
Reply With Quote
  #5  
Old 24-08-2020, 06:05 PM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Quote:
Originally Posted by Merlin66 View Post
Phil,
The standard SCT diagonal will fit the rear thread of the SCT.
The knurled floating ring is not removable, just ther to fit the SCT thread.

Damn.


Thanks Ken. The reason I ask is because I want to use it with the Baader cliplock system.



Looks like I'll be buying something like this, or similar.
Reply With Quote
  #6  
Old 25-08-2020, 11:10 PM
Sunfish's Avatar
Sunfish (Ray)
Registered User

Sunfish is offline
 
Join Date: Mar 2018
Location: Wollongong
Posts: 1,164
Usually a separate Celestron visual back will accept an adapter for an eye piece clamp or any other type of adaptor. Perhaps you should use an SCT visual back or SCT adaptor which is separate from the diagonal.
Reply With Quote
  #7  
Old 26-08-2020, 08:40 AM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Quote:
Originally Posted by Sunfish View Post
Usually a separate Celestron visual back will accept an adapter for an eye piece clamp or any other type of adaptor. Perhaps you should use an SCT visual back or SCT adaptor which is separate from the diagonal.

I've already bought the Baader Clip-lock adapter, hence the question.



Apparently it comes with an adapter that can be used for my purposes.
Attached Thumbnails
Click for full-size image (898125-1.jpg)
73.8 KB20 views
Click for full-size image (898125-2.jpg)
70.4 KB17 views
Click for full-size image (898125-3.jpg)
71.8 KB17 views
Reply With Quote
  #8  
Old 28-08-2020, 06:36 AM
Don Pensack's Avatar
Don Pensack
Registered User

Don Pensack is offline
 
Join Date: Aug 2006
Location: Los Angeles
Posts: 404
LOL.
The chrome adapter is supposed to be threaded into the body of the diagonal in the place of the SCT-threaded one. It is not supposed to be threaded into the ring on the SCT attachment.
First, unscrew the SCT part with its ring, then thread the chome barrel into the diagonal body. By so doing, you convert an SCT threded diagonal to a refractor style and it yields a larger clear aperture through the diagonal.
Reply With Quote
  #9  
Old 28-08-2020, 08:13 AM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Quote:
Originally Posted by Don Pensack View Post
LOL.
The chrome adapter is supposed to be threaded into the body of the diagonal in the place of the SCT-threaded one. It is not supposed to be threaded into the ring on the SCT attachment.
First, unscrew the SCT part with its ring, then thread the chome barrel into the diagonal body. By so doing, you convert an SCT threded diagonal to a refractor style and it yields a larger clear aperture through the diagonal.

Thanks Don. That was my original question but no one could answer. The small crisscrossed grip is difficult to grab and the thing is on there tighter than a.....well, we all know the metaphor.



So you can confirm this part is actually removable?
Reply With Quote
  #10  
Old 28-08-2020, 08:31 AM
Don Pensack's Avatar
Don Pensack
Registered User

Don Pensack is offline
 
Join Date: Aug 2006
Location: Los Angeles
Posts: 404
It's removable or they wouldn't have packed the chrome barrel with the diagonal.
Look carefully at the inside around where the SCT barrel would thread. If you don't see setscrews, then it's just on there tight. After all, the body is not machined in one piece with the barrel, like TeleVue, so they threaded it in at some point. I don't recall any setscrews in that unit.
You might try a pair of rubber gloves to increase your hand strength or use a strap wrench. Either way, it'll unscrew. The thread in the body is the same 2" SCT thread as the ring on the SCT thread-on tube. That's why the chrome barrel threaded into the ring.
Reply With Quote
  #11  
Old 28-08-2020, 09:23 AM
Outcast's Avatar
Outcast (Carlton)
Always gonna be a NOOB...

Outcast is offline
 
Join Date: Oct 2008
Location: Cairns, Qld
Posts: 1,053
Hi Spidy,

My GSO 2" diagonal had a similar arrangement & it was tighter than tight...

I ended up having to use a set of grips & even with some padding, I managed to do some minor damage to the aesthetics of the knurled ring but, that was the only way it was coming off...

I didn't post earlier as I wasn't sure if the Celestron one would be removable but, after seeing Don's post, thought I would share my experience with the GSO one.

Cheers
Reply With Quote
  #12  
Old 28-08-2020, 10:20 AM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Thanks Don and Carlton, appreciate the responses.


Looks like I'll be using the strap wrench I used last night to remove the SCT adapter plate to install the .7 reducer.


I'll report back tomorrow.
Reply With Quote
  #13  
Old 31-08-2020, 08:52 AM
Spidy (Phil)
Registered User

Spidy is offline
 
Join Date: Apr 2020
Location: Melbourne, Australia
Posts: 78
Don and Carlton you are indeed correct, the piece does unscrew, with some persuasion.
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 01:43 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Advertisement
Limpet Controller
Advertisement
Testar
Advertisement
NexDome Observatories
Advertisement
Bintel
Advertisement
Astronomy and Electronics Centre
Advertisement