Revelation / Skywatcher Focuser Measurement Needed

[John]

I wonder if some kind person can provide me with a measurment from a Revelation / Skywatcher dual speed crayford focuser ?. This is the standard one rather than the low profile model. I need to know the diameter of the focuser flange/barrel that fits into the mounting plate that goes on the scope. Below is a scope-side view of the focuser with some dimensions already marked. I've added (rather crudely !) a purple arrow with a ? and thats the dimension I'm looking for.

Any help would be much appreciated

[Steve Ward]

Can you not scale it off the photograph given that you already know some key dimensions ... ?

[spaceboy]

Someone has retro fitted one to an original sw base if that's why you wanted to know John ?? It was a thread on SGL some time ago which I can no longer find but this is the guy who did it http://www.scopeyard.com/articles/revelation-crayford-focuser-on-skywatcher-250p

[John]

Thanks for the replies. It's actually an Orion Optics base that I want to fit it into and it's an old one which I believe was an early GSO unit.

I've tried scaling it from the photo and I've got 78mm-79mm but an actual physical measurement would be reassuring   

[spaceboy]

I just checked and the hole is 8cm across on my Revelation focuser John so you weren't far off with 79mm.

Hope this helps.

[John]

Thanks very much spaceboy

So thats an 80mm aperture in the mounting plate which would tally with a 79mm-ish flange to be inserted into it. Very useful