Focuser thread question

[cuivenion]

Hi. The Skywatcher 130PDS focuser comes with a 2 to 1.25" adapter. The 1.25" barrel unscrews giving you a male M42 thread on the section that fits into the 2" focuser. In addition to this there is also a female thread inside that the 1.25" barrel screws into. does anyone know what this thread is?

[cuivenion]

Here we go. M42 on the outside. Mystery thread on the inside.

[vlaiv]

To screw in 1.25" eyepiece holder?

[cuivenion]

5 hours ago, vlaiv said:

To screw in 1.25" eyepiece holder?

Yeah that's the one.

[vlaiv]

Well, I've not checked the actual diameter and thread pitch, but you might be able to use it as 1.25" filter thread maybe (although that would mean that it is slightly narrower than 1.25" body, and I doubt that 1.25" eyepiece holder would use such thread for attachment to 2".

[cuivenion]

Ah, if its not a common thread thats a shame. I was planning to get an adapter to attach a coma corrector.