Part identification

[Spidy]

https://flic.kr/p/2jvxfvs
https://flic.kr/p/2jvBKo3
https://flic.kr/p/2jvABBH
https://flic.kr/p/2jvxfzR


Can someone please identify this part? It came with the Celestron 9.25 Edge HD. What is it and where is it used?

[Atmos]

It looks a bit like a 2" extension tube, possibly something you'd thread onto a diagonal to get more back focus?

[bojan]

I think it is Universal 2" to M42*0.75 Thread Telescope Eyepiece Mount Adapter (https://www.ebay.com.au/itm/Lovoski-Universal-2-to-T2-M42-0-75-Thread-Telescope-Eyepiece-Mount-Adapter/183357420624?ssPageName=STRK%3AMEBI DX%3AIT&_trksid=p2060353.m2749.l2649)

[Gary47]

Could not be 2" to M42 as the thread could mot be less than M50, possibly M52.
Somewhere an eyepiece is missing its mounting tube.

[bojan]

It is the item but description is wrong... ( I bought it last year, now it waits to be used somewhere), should be "M50x0.75"
It is used with this (https://www.ebay.com.au/itm/SV159-2-SCT-Mount-Adapter-Ring-for-Schmidt-Cassegrain-Telescopes-Aluminum-Alloy/303612982268?hash=item46b0be73fc:g: qBYAAOSwmHBeHWI5&frcectupt=true), as camera adapter for SCT

[Spidy]

Thanks for the responses guys. When I saw it I was quite excited as it looked like it could solve my back focus issues. However, even though one end screws nicely into the COAG, the other end where it's meant to screw into the Adapter plate, didn't quite have the diameter.

[Merlin66]

It looks identical to my Orion prime focus adaptor.
A 2" male with a male 2" x 24tpi SCT thread at the end.

[Spidy]

Ken, can I hassle you for a photo while it's deployed so I can see end to end connections?

[Merlin66]

Phil,
certainly, I'll post an image first thing tomorrow.

[Merlin66]

The Orion prime focus adaptor splits into two parts.
The chrome nosepiece - a 2" male to 2" x 24tpi (SCT) male thread.
The black portion is a 2" x 24tpi (SCT) female thread and a male T thread (42mm x 0.75)
I use it to mount SCT accessories on my ED80. The image shows a reducer fitted to the adaptor.

[Spidy]

Thanks Ken.


This is why I got excited when I saw it. I needed to connect my image train to the Celestron Edge HD 9.25 and the only thing missing was a piece very similar to this. So, I tried to connect it to the back of the adapter plate (some refer to this part as the rear collar. I'm not sure which is correct), but it wouldn't fit.


It was very slightly too small to fit around the threads of the adapter plate. So I was forced to buy a part that others in the US are using.



I'm also confused as to the threading types. Can someone explain, or give a link to a webpage that explains all the different threads type AND where they attach to on a telescope. I thought the 24tpi (SCT) threads are the ones off the back of the adapter plate.


Lets not even start with T, T2, 42, 48 etc.etc.


Edit: Also, if someone could explain how to add image thumbnails to a post as opposed to the web links I used, that would be much appreciated.

[Merlin66]

Spidy,
First things first...
To attach an image to a message...
At the bottom of the screen you'll see a section marked "Additional Options", the second box "Attach files" click the "Manage attachments" and a Pop up menu will allow you to upload image images. Note the image size limits.


OK.. the original image you linked was an adaptor with a male external thread? This thread looks like the SCT rear port thread?
All SCT's Celestron, Meade etc have the same basic male thread at the rear cell.
(There's a 3.25" thread hidden underneath the rear cell thread of the Meade. Used by things like Peterson's Eye Opener attachment https://optcorp.com/products/peterson-eyeopener-for-10-14-meade-lx-acf-telescopes)
Obviously the 2" nosepiece wouldn't fit the rear cell male SCT thread.....
It sounds like your COAG has a female SCT thread(?) why not directly attach that to the rear cell? I assume it's one of these, do you have all the attachments?? https://www.bintel.com.au/product/celestron-off-axis-guider/?v=322b26af01d5



You may be looking at the front of the nosepiece...this has a 48mm filter thread, for 2" astronomical filters.

[38degsouth]

Try this:

https://agenaastro.com/articles/guides/miscellaneous/astronomy-threads-explained.html

Regards, Dean

[Spidy]

Thanks for that.





The male thread fits the COAG female thread, but the female thread of the adapter does not fit over the Adapter plate's male thread.





Yep, agreed. That's where the .7 reducer or the adapter plate thread to. From the reducer, you connect the adapter plate as those threads are the same. However, from the adapter plate onwards, the threads are smaller, but no quite 48mm.




Yep, I think you hit the nail on the head. This is a piece to use with 2"screw in filters before your eyepieces. At least that's how I see it.

[Spidy]

Excellent resource. Thank you Dean. I've already bookmarked it for future reference!:thumbsup:

[Spidy]

Finally figured it out ;)