Yet another adaptor question.

[michaelmorris]

I know, that pesky Michael Morris keeps asking questions about obscure adaptors. What is with him - is he obsessed with adaptors or something?

Well I suppose I am a bit at the moment. I'm starting down the DSO imaging route ("turn back before it's too late" I hear you cry) and I've realised that I have way too much 'flop' in my set up. I need to make it all much more rigid (double Entendre - treble entendre even).

The worst bit at the moment is the connection between my DSLR and the focusser on my 80ED. To achieve focus I have to put in a 2" extension and it flops around everywhere. The stock crayford focuser on the Orion 80ED has a 55mm wide thread on the end of the drawtube, to which is screwed in the 2" eyepiece holder. This is all standard kit that came with the scope.

At the moment the train goes:

Focus Drawtube > 2" eyepiece holder > 2" extension > 2" to T thread adaptor > T thread to EOS adaptor > camera. All the flop is in the sections highlighted in red.

If I could get an adaptor that threaded to the 55mm thread on the focuser drawtube at one end and a T thread at the other I could remove most of the flop in my system.

So two questions.

1) Does anyone know what the thread size is on the end of the draw tube?

2) Does anyone know if anyone makes an off-the-shelf adaptor to directly connect this thread ot a T thread?

No more adaptor questions for at least an hour - honest.

[Merlin66]

Michael,

The thread on the ED80 is a 55mm x 1mm pitch thread.

I don't have what you're looking for but I did make an adaptor for my SCT fittings ( flip mirror etc) to fit the ED80.

So it had 55mm female thread at one end and a SCT male at the other.

Something similar but with a T thread would be the go....then you could add T thread spacers etc etc.

Ken

[michaelmorris]

Michael,

The thread on the ED80 is a 55mm x 1mm pitch thread.

I don't have what you're looking for but I did make an adaptor for my SCT fittings ( flip mirror etc) to fit the ED80.

So it had 55mm female thread at one end and a SCT male at the other.

Something similar but with a T thread would be the go....then you could add T thread spacers etc etc.

Ken

Thanks for the reply Ken. I suppose a 55mm to SCT adaptor would do the job as I already have a SCT to T thread adaptor. However, I am a bit concerned that the restricted lumen of 75mm of T extensions rings might cause some vignetting.

In an Ideal world, I'd want a 55mm thread on one end, then a 8 or 9 cm long 2" diameter tube with a male T thread at the other end.

[wayne weedon]

I may have the wrong idea but if it's the same thread as I had to fit the Skywatcher focal reducers to it's M56 x 1.

Tis such a shame there are almost no standards in this industry.

Wayne....