15 replies to this topic

[danhoffmann42]

Hello, I have what seems to be a pre-2007 xt8 dob skywatcher. I bought the Orion crayford focuser to replace the stock, but the new base plate is too large for the old hole. Does anyone know if there is an adapter/different plate that would work(the plate is a separate part from the rest of the focuser and tube), or any other solution that doesn't require drilling a new hole? The screw holes don't line up either. Thank you in advance.

[bgoody]

 I have the same question.  After many years of good service, my old pre-2007 focuser has finally gotten a bit wonky.  It's skews diagonally as it's extended which makes collimation mostly guesswork.  

[Jon Isaacs]

Hello, I have what seems to be a pre-2007 xt8 dob skywatcher. I bought the Orion crayford focuser to replace the stock, but the new base plate is too large for the old hole. Does anyone know if there is an adapter/different plate that would work(the plate is a separate part from the rest of the focuser and tube), or any other solution that doesn't require drilling a new hole? The screw holes don't line up either. Thank you in advance.

 

It's possible/likely that your scope was made by GSO. If you can post a photo, I can tell.. 

 

Jon

[Jon Isaacs]

 I have the same question.  After many years of good service, my old pre-2007 focuser has finally gotten a bit wonky.  It's skews diagonally as it's extended which makes collimation mostly guesswork.  

 

If you could post a photo of the focuser, I can probably identify it and offer some suggestions.

 

Jon

[danhoffmann42]

I can't upload a picture, but my new focuser plate hole is too big for the existing hole in my scope. The new focuser is an Orion 2" crayford. I guess the pre 2007 Orion xt8 focusers had a smaller hole. Thank you. Please let me know if you have any solutions.

[Jon Isaacs]

I can't upload a picture, but my new focuser plate hole is too big for the existing hole in my scope. The new focuser is an Orion 2" crayford. I guess the pre 2007 Orion xt8 focusers had a smaller hole. Thank you. Please let me know if you have any solutions.

 

Orion XT-8s were made mostly by Synta but some were made by GSO. The GSO focusers were better and had a smaller mounting pattern.

 

If your focuser looks like this, it's a GSO.

 

https://agenaastro.c...eed-bundle.html

 

Jon

[Bill Weir]

I have a 6” Orion dob I bought way back in 1999. After more than a few years I decided I wanted to put a 2” focuser on it so ordered one of the early Moonlight crayfords. I fully expected to have to carve out a larger hole but was pleasantly surprised to see a hole perfectly capable of accepting the draw tube. All I had to do was drill 4 new holes for the mounting screws. I didn’t even take the secondary out.

 

How much bigger does the hole in the scope need to be?

 

Bill 

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[Jon Isaacs]

I have a 6” Orion dob I bought way back in 1999. After more than a few years I decided I wanted to put a 2” focuser on it so ordered one of the early Moonlight crayfords. I fully expected to have to carve out a larger hole but was pleasantly surprised to see a hole perfectly capable of accepting the draw tube. All I had to do was drill 4 new holes for the mounting screws. I didn’t even take the secondary out.

 

How much bigger does the hole in the scope need to be?

 

Bill 

 

In 1999, Orion Dobs were manufactured by GSO rather than Synta.

 

Jon

[scotsman328i]

I have a 6” Orion dob I bought way back in 1999. After more than a few years I decided I wanted to put a 2” focuser on it so ordered one of the early Moonlight crayfords. I fully expected to have to carve out a larger hole but was pleasantly surprised to see a hole perfectly capable of accepting the draw tube. All I had to do was drill 4 new holes for the mounting screws. I didn’t even take the secondary out.

 

How much bigger does the hole in the scope need to be?

 

Bill 

Bill, I bought a MoonLite 2” CR focuser for my Orion XT8 Plus back in 2019. I was lucky when I bought mine. MoonLite already made their focuser to fit the Orion XT Line without any drilling necessary, and it came with a 1/2” and 1” spacer to ensure there was enough focuser back travel. It totally added a luxurious feel to viewing. They’re so nice! 
 

Edited by scotsman328i, 25 March 2025 - 07:29 AM.

[danhoffmann42]

The hole needs to be expanded by an 1/8 of an inch, I would guess.

[danhoffmann42]

Scotsman, do you think the moonlite would be a direct fit into a pre 2007 xt8?

[scotsman328i]

Scotsman, do you think the moonlite would be a direct fit into a pre 2007 xt8?

Dan, that I really don’t know. I’d either call Ron or send him a message. He can definitely answer that question for you and advise on purchase, installation and any troubleshooting. 
 

https://focuser.com/contact.php

[danhoffmann42]

Scotsman, do you think the moonlite would be a direct fit into a pre 2007 xt8?

[danhoffmann42]

Thank you.  I went to the link and it says that they only produce motorized focusers now.  I think a GSO may be my best chance.

[scotsman328i]

Thank you.  I went to the link and it says that they only produce motorized focusers now.  I think a GSO may be my best chance.

Oh no! Yeah, the GSO focuser is pretty good I’ve read. 

[Bill Weir]

The hole needs to be expanded by an 1/8 of an inch, I would guess.

Do you have access to a hole saw of the size needed? If so then remove the spider and clamp a short piece of 2X4 so it orientates under the focuser hole. Now you have something to centre the saw then drill away.

 

Bill