skyliner dob 2" adaptor.

[rory]

i want to get a orion or antares pricision centralising adaptors. thing is my dob which was second hand has only the 1.25" attachment. i believe i need the 2" attachment for the centralising twistlock adaptor ?

can anyone suggest where i can obtain one of these 2" attachments/adaptor. having never used or seen these adaptors im clueless in finding one , more importantly the correct one for the skyliner . thanks for any advice.

this is what ive got at the moment.

[rory]

looking at it again, i think that the piece still attached to the focuser tube might actually be the 2" part ? i just thought it would protrude up further like the 1.25" does ? mmm.

[John]

I think there is a 2" adapter needed. Check out this video - the scope in it is using the arrangement you are aiming for I think:

[rory]

thanks john, yeah it would seem looking at the vid i need a 2" atachment wich would slip into the piece left on the focuser which is held in with the two screws.

when i look at astro sites the 2" stuff has things like "threaded " and more common "t adaptor" i take it thats not what i want ?

anyone out there point me toward a "regular run of the mill,come with the scope " type adaptor for two inch eyepiece's ?

thanks in advance .

[Damo636]

I think the first item on this listing is what you are looking for Rory... http://www.astrobuysell.com/uk/propview.php?view=56796

[rory]

I think the first item on this listing is what you are looking for Rory... http://www.astrobuysell.com/uk/propview.php?view=56796

i think you may well be right there damo. cheers.

[coulthamst]

I have been searching for what I think you are looking for. Correct me if I have misunderstood, but does the adaptor need to fit into the focuser tube at a measurement of 55mm diameter? If so, the item Moonshane has on offer measures 50mm and is a 2" -1.25mm adaptor. I contacted him myself in case he had what I wanted, but found it wasn't the part I needed.

The required item is described by Skywatcher (but not by anyone else!) as an "eyepiece holder, 2"", and I have one coming from Rother Valley Optics for £25 plus P&P.

[rory]

thanks for info coulthamst. ive bought the adapter from b&s now, from moonshane. if it turns out not the part i need ,i can always pop it back on the b&s site.

theres a plastic holder that screws into the the metal focuser tube,that holder has two large screws that holds the 1.25" you can see in my pic im holding the 1.25" and the threaded plastic holder is still on the tube. so i need the 2" equivelant of that ,that'll slot into that .

i'll check out r.v.o too. thanks,

[Moonshane]

it really depends on the diameter of the little dovetail that goes into the main focuser. the one I have is 50mm.

[rory]

it really depends on the diameter of the little dovetail that goes into the main focuser. the one I have is 50mm.

the measurement of the dovetail at its narrowest point is 50mm on my 1.25 ,tapers out to 56mm, so i think its fine. like i say ,if not i'll flog it on no probs.

i think ive found a pic of what i need .

here.

[coulthamst]

Hi Rory. Looking carefully at the pic you posted in your initial post and the one you posted at 10.28pm I think we are talking about the same components . I regret to have to say that my measurement of the dovetail OD/focuser ID was somewhat cursory, and on checking the dimension is 57mm. Best of luck with your search.

[coulthamst]

Quick update on my adaptor purchase:- arrived today recorded delivery from RVO. Ordered yesterday, P&P £2. Delighted with service.

[rory]

nice one coulthamst. are you getting some 2" eyepieces then ?

[coulthamst]

Hi Rory. 2" eyepieces are not the issue. My favourite eyepiece, the one that gets by far the most use, is a Speers-Waler Mk II 17mm. Its one drawback is that it needs an unusually large amount of in-travel of the focuser, more in fact than is available with my focuser/scope configuration.

So I have in fact obtained the adaptor to hack about half an inch off it so as to have (with a 2"-1" adaptor) the capability of handling any of my eyepieces with out so much faffing about as I have had to put up with since I got the scope!

I spent a pleasant afternoon today drilling and tapping new screw holes, followed by the aforesaid hacking, and finishing off by filing the result back to dead square so that the eyepieces won't be out of alignment.

I have retained the unmodded original adaptor against the need for it if I sell on the scope in the future. How's that for obsessive?

[rory]

unfortunatly the aquired adaptor was'nt quite the correct size .

so im in the hunt for one with 56mm dovetail. ive placed a wanted ad on astro B&S.

or if anyone knows where they can be obtained cheapishly (is that a word ?)

do tell, ta.