Sky Watcher Focuser Adaptors

[Greg Shaw]

Hi Everyone

I was wondering if someone could shed some light on the minefield that is of focus tube adaptors.

Before getting my scope (150PDS) I did not consider how important these were to achieving focus. I thought they just made the size of the opening larger or smaller to accommodate different size eye pieces.

It wasn't until I had my scope and trying different combinations that I realised I needed them to easily achieve focus.

The trouble is the stock ones that have come with the scope only use the grub screw fitting and I have wondered how accurate they are especially when using my Cheshire when collimating.

I was planning to replace the standard scope fittings (the main grub screw fitting and the two adaptors 2” and 1.25” with grub screws) with fittings that have compression fittings so that they hold better and ensure a central fitting. I was going to get the Baader click lock but was told that this would then mess up the focusing as I need to stick to the same adaptor lengths that come with the scope. 

I've measured my fittings as follows

The 2" adaptor is 4.7cm

 

The 1.25" adaptor is 3cm

 

The main fitting on the focuser is 1.1cm

 

I spoke to Rother Valley and they said a compatible clicklock would be the M54. This attaches directly to the drawtube. 

https://www.rothervalleyoptics.co.uk/baader-2-clicklock-clamp-m54.html

Has anyone tried this and have they also changed from their stock 2" & 1.25" adaptors with the Sky Watcher scopes?

I am also looking to get the Explore Scientific Coma Corrector which has a long 2” nosepiece and a helical focuser so I have been told I can achieve focus without the focus tube going into the light path of the primary mirror.

Hope you can help

Thanks

 

Edited August 27, 2020 by Greg Shaw

[Rob_UK_SE]

When I have previously had Sky Watcher dobs I have made this change too. The solution was the following:

1.  M54 adapter for the focuser. This replaces the one shown in your final picture and benefits from two securing points and a brass compression ring. This is currently available from FLO https://www.firstlightoptics.com/adapters/astro-essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

2.  I found that I needed a 2” replacement tube with a 35mm optical path. When using a non-flush mounting 1.25” reducer adapter this worked well and fit correctly. If you use a 50mm one you may struggle to achieve focus with some 1.25” eyepieces. Omegon were the only company I could find offering an 35mm extension tube. Below is a link to Astroshop who have them in stock. It also has a brass compression ring. https://www.astroshop.eu/extension-tubes/omegon-2l-extension-tube-35mm-optical-path/p,54437

3.  2” to 1.25” reducer adapter from FLO. https://www.firstlightoptics.com/adapters/baader-2-to-125-reducer-adapter.html

The other focuser upgrade available for Sky Watcher scopes is the Lacerta 1:10 microfocus unit: https://www.365astronomy.com/Lacerta-Dual-Speed-1-10-Microfocus-Upgrade-Kit-for-Skywatcher-Crayford-Focusers.html

... when you add everything up you are looking at quite an investment, but it does protect your lovely eyepieces from barrel marks.

Edited August 27, 2020 by Rob_UK_SE

[pregulla]

I use 40mm long 2" extension tube + low profile 2" to 1.25" adapter, about 10mm tall. All my 2" and 1.25" come to focus, 35mm would work too, 50mm is too much.

BTW brass compression ring doesn't help to center the eyepiece, it just prevents the screw from leaving marks on the barrel, it even may hold some eyepieces with undercuts worse than just a screw

[Greg Shaw]

Thanks for the replys so far.

I have been told that this adaptor is not very good essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

Are there any click lock style adaptors and or extension tubes that would work with the focuser on this scope?

Has anyone tried this one? essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

I guess the only time I want to be properly accurate is when using the cheshire for collimation. I want to make sure its central when making the adjustments.

 

 

 

Edited September 2, 2020 by Greg Shaw

[Rob_UK_SE]

1 hour ago, Greg Shaw said:

Thanks for the replys so far.

I have been told that this adaptor is not very good essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

Are there any click lock style adaptors and or extension tubes that would work with the focuser on this scope?

Has anyone tried this one? essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

I guess the only time I want to be properly accurate is when using the cheshire for collimation. I want to make sure its central when making the adjustments.

 

 

 

Your alternative one is the same one I shared before... which is positively reviewed on FLO (so should be ok?).

The Baader one is a click lock type, but is also much taller and more expensive. The additional height may impact your ability to find the focus position of certain eyepieces. Both of these would still require an extension tube (different -shorter- length for the Baader) in order for your eyepieces to reach focus and any locking mechanism is not securing the eyepiece, just the extension tube.

https://www.firstlightoptics.com/adapters/baader-2-clicklock-m54-clamp.html

It’s also worth considering whether, with all the additional focuser parts, at what stage would it Be worth just upgrading to a different/better focuser? I have recently upgraded a focuser for a fellow astronomer and can confirm that it is fairly straightforward. Please see below: 

 

Edited September 2, 2020 by Rob_UK_SE

[wookie1965]

I have a 2" to 1.25" adapter  that fits in your 2" focuser tube it has a compression ring you can have. 

[Greg Shaw]

19 hours ago, Rob_UK_SE said:

 

It’s also worth considering whether, with all the additional focuser parts, at what stage would it Be worth just upgrading to a different/better focuser? I have recently upgraded a focuser for a fellow astronomer and can confirm that it is fairly straightforward. Please see below: 

 

Because I have the 150DPS I have the dual speed focuser which has a 1:10 reduction ratio. So I wasn't looking to upgrade the focuser. I just thought that there might be better adaptors as I have seen some people use the twist locks in their videos and wondered if I could do the same with the Skywatcher.

Edited September 3, 2020 by Greg Shaw

[wookie1965]

https://www.rothervalleyoptics.co.uk/ovl-twist-lock-adaptor-2-125.html

Like this. 

[Pain in the Neck]

Hi @wookie1965

Is one of those 2” to 1.25” adaptors up for grabs / sale?

I have been looking at a way of protecting my Baader Hyperion EP’s from the dreaded grub-screw marks, and it looks like one of those adaptors might do the job.

Charles.

[wookie1965]

15 hours ago, Pain in the Neck said:

Hi @wookie1965

Is one of those 2” to 1.25” adaptors up for grabs / sale?

I have been looking at a way of protecting my Baader Hyperion EP’s from the dreaded grub-screw marks, and it looks like one of those adaptors might do the job.

Charles.

Sent you a pm

[amaury]

Sorry to revive this thread but I am about to do something very similar with the Baader Click-lock system.

I have a SW Skyliner 200p, same focuser fitting and adapters. (11mm and 47mm respectively of optical length)

That is an effective optical length of 58mm for any adapter. 

I am planning to change the fitting with the baader click-lock, the one below.

https://www.firstlightoptics.com/adapters/baader-2-clicklock-m54-clamp.html

That alone has a 30mm of optical length, I am guessing that is too short to the "stock" optical length. I'll be missing 27mm of back-travel in my 2" eyepieces. 

Baader also sells a 2" 37mm extension

https://www.firstlightoptics.com/adapters/baader-2-clicklock-clamp-37mm-extension.html

On 27/08/2020 at 18:10, Rob_UK_SE said:

I found that I needed a 2” replacement tube with a 35mm optical path

Somewhat close to this.

That brings the total optical length to 67mm for my 2" EPs, that means I'll be missing around 9mm of in-travel. Is this ok? or should I disregard the click-lock system completely?

I only do visual. 

Thanks in advance

[Barry-W-Fenner]

10 hours ago, amaury said:

Sorry to revive this thread but I am about to do something very similar with the Baader Click-lock system.

I have a SW Skyliner 200p, same focuser fitting and adapters. (11mm and 47mm respectively of optical length)

That is an effective optical length of 58mm for any adapter. 

I am planning to change the fitting with the baader click-lock, the one below.

https://www.firstlightoptics.com/adapters/baader-2-clicklock-m54-clamp.html

That alone has a 30mm of optical length, I am guessing that is too short to the "stock" optical length. I'll be missing 27mm of back-travel in my 2" eyepieces. 

Baader also sells a 2" 37mm extension

https://www.firstlightoptics.com/adapters/baader-2-clicklock-clamp-37mm-extension.html

Somewhat close to this.

That brings the total optical length to 67mm for my 2" EPs, that means I'll be missing around 9mm of in-travel. Is this ok? or should I disregard the click-lock system completely?

I only do visual. 

Thanks in advance

Hi Amaury

https://www.firstlightoptics.com/adapters/baader-2-inch-click-lock-cl-extension-47mm.html

I have just purchased one of these for my 300p. The overall length is identical to the standard 2" skywatcher extension. I have fitted this along with a 1.25 to 2" click lock adapter. It works very well.

[amaury]

13 hours ago, Barry-W-Fenner said:

Hi Amaury

https://www.firstlightoptics.com/adapters/baader-2-inch-click-lock-cl-extension-47mm.html

I have just purchased one of these for my 300p. The overall length is identical to the standard 2" skywatcher extension. I have fitted this along with a 1.25 to 2" click lock adapter. It works very well.

Hi Baz, 

It's good to hear from you.

The click-lock systems is lovely yes. The one you point at is the extension bit only.

I want to change the 2" focuser fitting/adapter as well (the M54 connection)

I might get this one plus the extender you mention. 

https://www.firstlightoptics.com/adapters/astro-essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

Going fully click-lock makes the fitting plus the 37mm extension 10mm too long, I am not sure if I'll need those 10mm of in-travel focus. 

[atkar83]

On 19/04/2021 at 00:39, amaury said:

Hi Baz, 

It's good to hear from you.

The click-lock systems is lovely yes. The one you point at is the extension bit only.

I want to change the 2" focuser fitting/adapter as well (the M54 connection)

I might get this one plus the extender you mention. 

https://www.firstlightoptics.com/adapters/astro-essentials-2-inch-compression-ring-adapter-for-sky-watcher-newtonians-and-72ed-refractor-m54.html

Going fully click-lock makes the fitting plus the 37mm extension 10mm too long, I am not sure if I'll need those 10mm of in-travel focus. 

 

Hey, sorry to bump an old thread, but I was wondering if this setup (Astro Essentials 2-inch Compression-Ring adapter replacing the OEM one that attaches to the focus tube and the "Baader 2inch ClickLock with 2inch CL Extension 47mm" replacing the OEM 2" extension tube) worked for you? I have a Classic 200p 8" dob also, and purchased a Baader Hyperion Zoom M4 with barlow for my high power viewing, and will be buying a low power wide field EP soon. Since the later will be 2", and the Zoom comes with a 2" skirt option, I thought a 2" twist lock will make it very easy to switch between the two EPs (and they're basically all I would purchase for the next few years). Would your setup let me achieve focus this way? I've read that if I add the barlow to the BHZ it can only be used in the 1.25mm format, but I do have a 2" to 1.25" adapter worst case scenario (hopefully that would attach to the Baader ClickLock, don't see why it wouldn't), and that should add a bit more height to make the barlow focus work, if I'm not mistaken. Thanks