Self-centring adapter advice please

[Jules Tohpipi]

I’ve been thinking of buying a self-centring adapter for my telescope, but after a lot of reading I’m rather confused.  I wonder if anyone can advise for my particular circumstances please?

Gear

• Skywatcher 10” FlexTube Dob used for visual only
• EPs are all 1.25” and it’s highly likely to stay that way
• Dob has the dual-speed Skywatcher Crayford focuser

My main aim is to achieve a set-up that allows for accurate, consistent, and repeatable collimation for better visual IQ across my EPs.  The other benefits of an SCA would be a bonus but non-essential.

Now, if I’m understanding correctly then:

• I require a 2” to 1.25” SCA?
• The SCA would be inserted into my 2” Skywatcher EP holder?
• I then insert the EP into the SCA and tighten? 

My concerns are:

• Is this a worthwhile upgrade for visual-only observing?
• Is the Skywatcher dual-speed Crayford of good enough quality to see the benefits of the SCA?
• Do things go out of alignment anyway, from session to session, because the Skywatcher 2” EP holder has to be secured with thumbscrews?

Open to suggestions on a suitable SCA, but I like the look and concept of the Howie Glatter Parallizer (and indeed his collimators but would be using a Cheshire in the shorter-term). 

Any opinions gratefully received...

[sbooder]

I use the Orion SCA for both my collimation and for visual when using 1.25" EPs and I would not be without it.  Apart from anything else it keeps your EPs in better nic than thumbscrews.

I was trying to get an adapter made that would screw directly to my focuser tube (as the 2" thumbscrew bit comes off) and the other end would have a thread to match the 2" thread of the bottom part of the Orion SCA, doing away with thumbscrews altogether.

[wookie1965]

I found that collimation with a Cheshire is a lot more accurate now because the SCA centres it better, my eyepieces dont have any marks on them now either from the thumb screw.

[rwilkey]

I have the Orion SCA too and it's a great bit of kit, so I always have the 2" adaptor attached to the scope and use the SCA to use with my 1.25" ep's.  I recommend this bit of kit.

[RikM]

I have the same Orion SCA and it works well. Though I bought mainly to avoid fiddling with thumbscrews in the cold rather than to help with collimation.

[russ]

Superb bit of kit. We have an Antares (identical to the Orion) on our C6.

My only word of caution would be the Revelation version. I bought one for a second scope, went for the Revelation because it was 50% cheaper than the Antares/Orion, and regretted it straight away. Just didn't work anywhere near as well.

[rory]

Superb bit of kit. We have an Antares (identical to the Orion) on our C6.

My only word of caution would be the Revelation version. I bought one for a second scope, went for the Revelation because it was 50% cheaper than the Antares/Orion, and regretted it straight away. Just didn't work anywhere near as well.

I agree with Russ ,I had a revelation twist lock and it was ok but not as smooth as the Orion version. I absolutely loved mine , far less faffing in the dark with little thumb screws. I will certainly get another when I get a suitable set up.

[JED-E3]

I’ve been thinking of buying a self-centring adapter for my telescope, but after a lot of reading I’m rather confused.  I wonder if anyone can advise for my particular circumstances please?

Gear

• Skywatcher 10” FlexTube Dob used for visual only
• EPs are all 1.25” and it’s highly likely to stay that way
• Dob has the dual-speed Skywatcher Crayford focuser

My main aim is to achieve a set-up that allows for accurate, consistent, and repeatable collimation for better visual IQ across my EPs.  The other benefits of an SCA would be a bonus but non-essential.

Now, if I’m understanding correctly then:

• I require a 2” to 1.25” SCA?
• The SCA would be inserted into my 2” Skywatcher EP holder?
• I then insert the EP into the SCA and tighten? 

My concerns are:

• Is this a worthwhile upgrade for visual-only observing?
• Is the Skywatcher dual-speed Crayford of good enough quality to see the benefits of the SCA?
• Do things go out of alignment anyway, from session to session, because the Skywatcher 2” EP holder has to be secured with thumbscrews?

Open to suggestions on a suitable SCA, but I like the look and concept of the Howie Glatter Parallizer (and indeed his collimators but would be using a Cheshire in the shorter-term). 

Any opinions gratefully received...

Does your current 2" to 1.25" adapter sit flush or has it got an extension? I know on some the 1.25" eyepiece sits about 45mm higher.

James. 

[ChrisLX200]

On a related tack, I don't know why they only offer a single screw for holding eyepieces and accessories into adapters, I usually drill and tap through for an extra one at 120deg around the circumference, holds stuff much more securely. I noticed last night after slotting in the Lodestar that it could move a bit no matter how tight the single screw that held it, then realised the adapter only had that one screw so put another in. Very secure now.

ChrisH

[Jules Tohpipi]

Thanks for all the replies. Definitely seems like a good bet then.

James: no the Skywatcher adapter does not sit flush; it's a one-piece item with an integral extension tube.

[JED-E3]

.....................no the Skywatcher adapter does not sit flush; it's a one-piece item with an integral extension tube.

If you have to use a separate extension tube you might loose some of the benefit of your self centring adapter.

[Jules Tohpipi]

Thanks for the heads up.

Earlier today I ordered a Howie Glatter Parallizer from FLO who seem confident that I won't encounter any focusing problems or need extension tubes on the 250px. I mainly ordered it because of the outstanding praise from users on the other side of the pond.

The Parallelizer should arrive early next week, so I'll report back with the results for the benefit of the knowledge pool.

[rory]

Good lord that's a hell if a name

A howie glatter paralleliser ?

Is that a doctor who weapon ?

[RikM]

Thanks for the heads up.

Earlier today I ordered a Howie Glatter Parallizer from FLO who seem confident that I won't encounter any focusing problems or need extension tubes on the 250px. I mainly ordered it because of the outstanding praise from users on the other side of the pond.

The Parallelizer should arrive early next week, so I'll report back with the results for the benefit of the knowledge pool.

I guess it depends on your eyepieces but I always assumed you'd still need the 35mm 2" eyepiece adaptor in the draw tube to reach focus. That's what I have with the Orion adaptor and I think the Parallizer adds about the same distance. I would be very keen if you could confirm that you can reach focus and with which eyepieces

[Solar_observer]

I have just bought the revelation sca,how do the Orion and the Altair versions better this one? Have I made a mistake in buying the revelation one?

Clear skies to you all :-)

[Solar_observer]

Sorry ment the antares.....NOT Altair

Clear skies to you all :-)

[rory]

No not mistake, but I found it slightly stiffer and had a rougher feel when rotating. But it works on the same principle so I wouldn't worry.

The Orion/Antares had a feel that it had been slightly better engineered , smoother .

[Solar_observer]

Ah that's a relief,thanks Rory. Can't wait to assemble it all on Monday when my 200p arrives :-)

Clear skies to you all :-)

[Jules Tohpipi]

Good lord that's a hell if a name

A howie glatter paralleliser ?

Is that a doctor who weapon ?

Ha, ha! That's exactly what I thought! But I'm finding it rolls off the tongue in quite a cool kind of way now. Lol. And 'Parallizer' has a clever double-meaning. Ooo, and it sounds like something from Hitchhiker's Guide to the Galaxy. He seems to be an interesting guy and regularly pops up on forums to advise and clarify things about his products. So, count me in for for giving some of his stuff a try!

I guess it depends on your eyepieces but I always assumed you'd still need the 35mm 2" eyepiece adaptor in the draw tube to reach focus. That's what I have with the Orion adaptor and I think the Parallizer adds about the same distance. I would be very keen if you could confirm that you can reach focus and with which eyepieces

Yes, this is one of several things I'm still in the dark about. If I'm understanding the principle correctly, then it should work better if inserted directly into the draw tube - rather than into the SW 2" EP adapter. Unfortunately, I forgot to ask FLO this in my email. But I will try it both ways and report back when it arrives.

Breaking news.... it has just arrived while typing this! Only ordered late yesterday morning, and here it is less than 24 hours later -- on a Saturday morning. Yet more brilliant service from FLO.

[wookie1965]

I wasn't sure at first and presumed there was something wrong with my scope when I first put my SCA in I couldn't reach focus it was like RikM said had to put the 2" adapter in to reach focus.

[Jules Tohpipi]

Well, it was a beautiful day here. That is until 5pm when I watched the clouds roll in. So I've been having a play with the Parallizer indoors instead.

Now, I temporarily have two telescopes in the house - for which the results have been rather different.

For reference, the diameter of the Parallizer is a hair's breadth under 2" according to my Vernier Caliper.

Skywatcher Skyliner 250px FlexTube Dob

This particular telescope has the Skywatcher Dual-Speed Crayford Focuser fitted (non low-profile version). The Parallizer will not fit in the draw tube because the diameter of the Parallizer is too big. Therefore, the Parallizer must be fitted to the 2" EP holder supplied with the telescope. Then I can insert my 1.25" EPs into the Parallizer to look at the underside of all the clouds.

Skywatcher Skyliner 200p Dob

This telescope is around one year old and unmodded. It has the single-speed focuser. The Parallizer fits perfectly directly into the draw tube. Now, this next section is a bit difficult to describe without diagrams but I'll give it a go. It's difficult to describe because the outside dimensions of the adapters don't quite tell the whole story. Anyhow, I'll stick to the overview for now. The supplied Skywatcher 2" to 1.25" adapter (which is intended to be fit directly to the draw tube) provides around 45mm of extension (46.5 mm according to my measurement on the calipers). If you insert the Parallizer directly to the draw tube then it provides no extension. (The Parallizer has a 9 mm tall knurled collar; however, it is chamfered on the inside so provides no extension). But the good news is that all is not necessarily lost if you need some extension to achieve focus. The length of the barrel on the Parallizer (as measured from below its collar) is around 35mm. So let's not insert the barrel all the way into the draw tube. Let's insert it only, say,10mm in to allow for clamping inside the draw tube (as does the SW adapter). Great, so now at least we have 25mm of extension compared to 45mm of the Skywatcher adapter. Still with me? Where am I going with this? Well, if I don't insert my EPs all the way in to their collars, then I was able to get effectively 45mm of extension using the Parallizer (I just clamped the EPs at the end of the barrel and did not rely on dropping the EPs all the way in until they hit their collars). Therefore, on the 200p, it might well be possible to achieve focus - even if inserting the Parallizer directly into the draw tube. Will have to wait for clear skies to find out one way or the other.

Build quality

I'll save a fuller review for later, but build quality of the Parallizer is every bit as good as I was lead to believe. Now I have it in my hands and can look at the design, it's apparent how it works and achieves its goals. It's a very simple and clever idea. That side of things *definitely* needs a diagram! Simple if you see it but difficult to explain in words.

Will update further when opportunity arise to point the scopes at the sky...

[wookie1965]

On the 200 this means you have to get the eyepiece in at just the right amount each time and in the dark changing eyepieces going to be a bit of a faff.

[Jules Tohpipi]

Possibly, but then the EPs might achieve focus pushed all the way in, or pushed anywhere in so long as in the range from 10%-70%. Just hoping for a break in the clouds to have a play.

[wookie1965]

I tried that with mine it didn't work may do on yours i have the 2" adapter in now and the SCA. At one spell i had the eyepiece right on the end got focus but as soon as i put higher power  one in it wouldn't focus again.

[Jules Tohpipi]

A quick update.

Had the 250px DOB out for a brief observing session tonight. Was able to achieve focus with all my EPs. That's the 6mm WO, 16 & 24mm MaxVisions. Just to recall the set-up: this scope has the SW dual-speed focuser fitted. I inserted the 2" EP holder into the draw tube, then the Parallizer (all the way in to the collar), and then my 1.25" EPs. (The Parallizer won't fit direct into the draw tube on this focuser).

Even with the dreadful seeing tonight, the results were very promising. I had carefully collimated the scope at the weekend with the Parallizer in place. Learnt a few things about it in the process, which I'll save for a later report. Once collimated, I removed and then reinserted the 2" EP holder, Parallizer and Cheshire multiple times over and every time the view down the Cheshire was identical. So that's a 10/10 for repeatability and consistency. The only thing I had to be careful about was ensuring the entire circumference of the collar of the 2" EP holder was butted up against the draw tube before securing its screws. Then I got consistent views down the Cheshire every time.

Regarding the 200p Dob, unfortunately I didn't get chance to try that out with the Parallizer tonight. The scope is in an upstairs bedroom and I didn't want to risk waking our little one (technically, I didn't want to risk my wife murdering me for waking our little one). The Parallizer will go straight into the draw tube on this, and although I'll be selling scope, I'm still curious to see if it can achieve focus without extension tubes.