GSO 2" Barlow problem and Eyepiece Query

[knightrider]

Hi Guys,

2 questions today or opinions.

Has anyone else had a problem with their GSO 2" ED Barlow not having enough inward travel on their skywatcher scope?

Skywatcher provides a 2" adapter for the 2" focuser. When using the 30mm superview with it, it works fine. But inserting the Barlow into adapter it bottoms out and still has an inch to go, thus requiring more inwards travel to achieve focus...

I can remove the 2" adapter and insert the barlow directly into the focuser, but not all the way because that doesn't reach focus either. Rather I have to manually pull it back about 2" before I can start to achieve focus.

It's proving to be more an annoyance than a convenience.
Is there anything I can do to make life easier?
Maybe taking the adapter into machining shop and have them turnout the bottom lip to allow the barlow to insert fully??


Second Q.
I have a GSO 2" 30mm Superview, is there any advantage to me owning this eyepiece than a 1.25" variant of similar specs and quality?

It works quite well, I was wondering for convenience sake if I would be reaping the same results with a 1.25" 30mm wide angle eyepiece.
Primarily because my filters I own are also 1.25" and it saves swapping adapters in the dark to change eyepieces....

Thanks guys

[malclocke (Malc)]

I am putting together a dob at the moment with what I believe is a skywatcher focuser and noticed the same problem today when I was loading up as many accessories as possible to check balance, see attached photo.

In my case the barlow fits through the 2" adapter, but the The barrel of the focuser seems to be slightly under the 2" barrel size of the barlow. The barlows fits fine in the GSO focuser on my GSO dob.

I don't have any advice to offer I'm afraid, just to say that you're not alone!

Malc

[knightrider]

Hi Malc,

Yes your focuser looks like the one on my dob. And I can see yours is doing the same thing. I had another look at the 2" adapter today, it wouldn't be possible to machine out the bottom lip as it houses a thread and is part of the flange that locks into the focuser.... :/

[janoskiss (Steve H)]

I used to have this same focuser on my Saxon (Synta / i.e. SW) 10" Dob. The adapters are badly designed on these. I ditched the focuser for a GSO 10:1 Crayford style one. It is not a straightforward swap-over solution but if you have some basic tools (a drill and sharp drill bit of the right size being the most important) and rudimentary "handyman" skills, and take your time to think about what you're doing (e.g., no metal filings on the mirrors), it's so worth doing!

Initially I used a band-aid solution of a motorised focusser for a couple of years. Once I installed the GSO Crayford, I never looked back and wish I'd done it sooner!

[knightrider]

I was hoping to keep the focuser and scope intact as much as possible.
A 10:1 would be an upgrade, but the current one still serves it's purpose.

Bad design hey, seems to be the case. There's certainly nothing wrong with the barlow. I did buy the 2" barlow for the photography side of things also, so a little bit more unwilling to ditch for a 1.25" version than I am with the 2" eyepiece.

[knightrider]

I think I may have a solution. I've ordered a 2" parfocal ring to permanently leave on the barlow. If I use the barlow without the skywatcher adapter and just insert it straight into the focuser with the right set distance with the parfocal ring I can use it as I would normally...just without the adapter.

[astro_nutt]

When I brought my Saxon 10 inch dob some years ago it came with a 2 inch extension tube for use with 2 inch eyepieces to allow that extra travel..

[knightrider]

Well here it is, it arrived today.

I've fitted it to the barlow to hold it out of the focuser at the same distance as what it would be if it inserted fully into the 2" adapter.

It's been overcast here so I'll have to test it out later.
Hopefully this will makeshift a solution for me.
It only cost around $12 delivered from the UK.

[knightrider]

Just to update, The parfocal ring worked well. Was able to reach focus with everything including the camera. It's a bit of a makeshift solution though.

[knightrider]

Well I've had more success with the GSO barlow. I've removed the barlow element from the bottom and am using the rest of the unit as my adapter instead of the SkyWatcher adapters (both of them, 1.25" & 2").

Seeing as it is now essentially an extension tube that is exactly the height it needs to be to match the height of the skywatcher adapters, except it has inbuilt the 1.25" removable adapter in it also! Which is making swapping out my 1.25" eyepieces with the 2" ones a quick and easy breeze and vice versa, rather than having to physically change the complete adapter every time I want to swap eyepiece sizes.

And all I nee to do is screw in the barlow element on the bottom if i need to barlow, which is rare anyway. It's been one of my handiest buys now.

So, if you have one of these and a skywatcher scope with pesky adapters, this is a great way to make stepping up and down eyepieces easy.