S/W 200P 2" adaptor filter thread

[phw26]

Hi,

I have a recently purchased Skywatcher 200P which came with a 2”---1.25” adaptor. I have just purchased a 2” UHC filter, and have read in this forum that the filter would screw into the adaptor and I would be able to use it with my 1.25” eyepieces.

However the filter does not screw into the adapter. The adapter thread looks the same size as the filter but it will not screw in. The filter screws into the one 2” eyepiece I have so the thread is ok. Has anyone else had this problem or am I doing something wrong. Thanks in advance.

[rwilkey]

Hi Peter, this is an unusual problem, and I find my SW filters fit the adaptor snugly. It was possibly one of my threads that recommended this approach, it didn't cross my mind that one wouldn't fit as I use this method all the time very successfully. Could different makes make a difference? Though as you say, it fits the eyepiece OK. I am sorry if my thread may have misled you, I had no inkling that the filter would not fit in some cases.

[Merlin66]

I have various 2" to 1.25" adaptors, with 48mm filter threads.

Touch wood, all my 2" filters seem to fit any/ either adaptor...

Just double check the condition of the thread in the adaptor.

(BTW if and when you get it to fit, be VERY careful how you insert a 1.25" eyepiece...the nosepiece of the eyepiece may be longer than the available clearance distance and you could hit the filter...caution.)

[DOBBY]

I've tried skywatcher...orion..& baader filters this way & never had a prob in either of my 'scopes adapters... as Merlin said..check your thread

[Simms]

Hi Peter, could you post pictures of the items you are trying to pair - cant work out why it isnt working for you..

[phw26]

Thanks to everyone for there replies it is very much appreciated.

I have attached some photo's to help explain what my problem is.

These are the adapters that came with my scope.

Adapter "A" is the 2" adapter with the filter thread I am having problems with. I have measured the internal diameter of this thread and it is 46mm. The outside diameter of my filter thread is 47.6mm which explains why it wont screw in.

Adapter "A is screwed into "C" which makes up the eyepiece holder I use for using my 1.25 eyepieces. I would assume "C" would be threaded to take a 2" filter but as you can see from the picture it has no thread.

I therefor assumed I could join " A, B & C" together with the filter screwed into "A" , but as explained this is not possible.

My thoughts are; I need to replace "C" with one that has a filter thread. Am I right in thinking this or am I missing something obvious.

Many thanks again for all your help.

Best Regards

Peter

[Merlin66]

Hmm

Ok

Usually the FRONT of the 2" adaptor - closest to the telescope tube has the 48mm filter thread. I think your "A" is a "special" for the SW focuser.....

The normal 2" to 1.25" adaptor looks like this:

First Light Optics - 2" to 1.25" Eyepiece Adaptor

[phw26]

Hi Merlin66,

"A" is the 2" adapter that fits onto the focuser and then takes the 2" eyepiece. I don't use this as I am using 1.25 eyepieces with "B & C". Do you know if the adapter you suggest has a filter thread?

Thanks again for your help

Peter

[Merlin66]

yes,

the 2" to 1.25" has the 48mm filter thread up front.....