Baader Diamond Steeltrack NT Extension tube

[jpro747]

Hi,

I'm looking for a solution for my Baader Diamond Steeltrack NT focuser. The focuser drawtube has 40mm of travel, however my dobsonian telescope has a lot of back focus, and therefore needs around 80mm travel. So i'm essentially looking for a drawtube extension of around 40mm. The drawtube has an S58 dovetail receptor as well as an M55 female thread. I've looked everywhere  on the net for extension tubes to fit but to no avail. Perhaps someone knows if it's possible to have extension tubes made to your own specification? I'm not very keen on the idea of 2" extension tubes as they are known to cause vignetting, and that would be a last resort solution. 

 

Thanks,

James

[DRT]

Hi James,

I had a similar problem with my Orion Optics VX12 and solved it by buying two of these risers to add 38mm of height to the focuser...

These solve the problem very well and are much more stable that a long extension hanging from the focuser.

Derek

 

[YKSE]

Do you have Baader 2" clamp with SC thread? (It's in baader wedge, prism diagonal or for SC scopes)? put it together with a Baader's 2" nosepiece (in baader's 2" diagonals or 2" eyepieces), so that you can check if there's visible vignetting with this 2" extension. Clicklock on eyepiece side works more smoothly than 3 thumb screws.

[jpro747]

3 hours ago, DRT said:

Hi James,

I had a similar problem with my Orion Optics VX12 and solved it by buying two of these risers to add 38mm of height to the focuser...

These solve the problem very well and are much more stable that a long extension hanging from the focuser.

Derek

 

I have the same scope as you - VX12 (f/4). Your's looks like the old baader steeltrack, but I have the new diamond steeltrack and unfortunately the risers won't fit on it.  Though perhaps finding some kind of base plates to rise up the focuser might be a better way to go. 


 

 

2 hours ago, YKSE said:

Do you have Baader 2" clamp with SC thread? (It's in baader wedge, prism diagonal or for SC scopes)? put it together with a Baader's 2" nosepiece (in baader's 2" diagonals or 2" eyepieces), so that you can check if there's visible vignetting with this 2" extension. Clicklock on eyepiece side works more smoothly than 3 thumb screws.

Sorry, I'm not sure what you mean by SC thread. I've got the Newtonian variant focuser, sounds like your talking about a focuser for SCT telescopes? I've thought about the clicklock however it only gives a rise of 20mm and I need 40mm.

[DRT]

2 minutes ago, jpro747 said:

I have the same scope as you - VX12 (f/4). Your's looks like the old baader steeltrack, but I have the new diamond steeltrack and unfortunately the risers won't fit on it.  Though perhaps finding some kind of base plates to rise up the focuser might be a better way to go. 

Are you sure they are different?

FLO list these same risers as being accessories to the diamond steeltrack, albeit that they are currently out of stock.

[YKSE]

29 minutes ago, jpro747 said:

I have the same scope as you - VX12 (f/4). Your's looks like the old baader steeltrack, but I have the new diamond steeltrack and unfortunately the risers won't fit on it.  Though perhaps finding some kind of base plates to rise up the focuser might be a better way to go. 


 

 

Sorry, I'm not sure what you mean by SC thread. I've got the Newtonian variant focuser, sounds like your talking about a focuser for SCT telescopes? I've thought about the clicklock however it only gives a rise of 20mm and I need 40mm.

I'm talking about 2" extention

This is Baader's 2" extension,

http://www.teleskop-express.de/shop/product_info.php/info/p2433_Baader-2--extension---47mm-length---ClickLock.html

It comprises of a 2" clickclamp with SC thread, the same as this one

http://www.teleskop-express.de/shop/product_info.php/info/p2427_Baader-2--Click-Lock-eyepiece-and-Adapter-holder-for-2inch-SC-thread.html

and a 2" nosepiece, which is exactly the same as the nosepiece in their 2" eyepieces, or 2" diagonals.

What I meant was, if you have those parts, you can make this 47mm extension by yourself.

[jpro747]

30 minutes ago, DRT said:

Are you sure they are different?

FLO list these same risers as being accessories to the diamond steeltrack, albeit that they are currently out of stock.

100%, I ordered 3 of them from TS in Germany to try... they are now on their way back lol

 

 

4 minutes ago, YKSE said:

I'm talking about 2" extention

This is Baader's 2" extension,

http://www.teleskop-express.de/shop/product_info.php/info/p2433_Baader-2--extension---47mm-length---ClickLock.html

It comprises of a 2" clickclamp with SC thread, the same as this one

http://www.teleskop-express.de/shop/product_info.php/info/p2427_Baader-2--Click-Lock-eyepiece-and-Adapter-holder-for-2inch-SC-thread.html

and a 2" nosepiece, which is exactly the same as the nosepiece in their 2" eyepieces, or 2" diagonals.

What I meant was, if you have those parts, you can make this 47mm extension by yourself.

Ah right, thanks for the explanation. Wouldn't it be the same as using one of the 2" extension tubes and thus cause vignetting? http://www.teleskop-express.de/shop/product_info.php/language/en/info/p163_TS-Optics-2--extension--50-mm-long.html
I'd rather use a compression ring than the clicklock as I'm constantly rotating the equipment inserted into the drawtube to get the right framing. 
 

[YKSE]

Yes, it should be the same as using that 2" extension.

As to vignetting, if we're talking only about visual, since I know nothing about astrophotography, it's not necessary the extension tube is the cause, the 2" extension has 48mm inner thread (for 2" filters), and the largest field stop for a 2" EP is 46mm (41mm Panoptic , 42mm LVW, and 40mm SW Aero (TS Paragon etc), All UWA and XWA has much smaller field stop (e.g. 42mm for 31 Nagler, 38mm for 21 Ethos).

There're other sources can cause vignetting, like too small secondary in Newt, some EPs have vignetting by themselves.

As to compression ring vs clicklock, I find baader clicklock is far eaiser than 2 thumbscrews when I need rotating diagonal, trying filters, or changing EP, especially in the winter when the gloves are on.

[jpro747]

I'm going to try out the clicklock w/ 2" nosepiece and hope the vignetting won't be visible. It's a shame that Baader doesn't make anything any extension tubes . The Diamond Steeltrack is a relatively new focuser, so I hope either Baader or a third party will make an extension tube in the future. 

[YKSE]

You can run Mel Bartel's calculation to see if your secondary size and focus plane give good enough none-vignetted view.

http://www2.arnes.si/~gljsentvid10/diagonal.htm