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Crayford focusser Orion Optics UK
I have received a few questions about the height of the Crayford focuser on my 300mm Orion Optics UK Dobson. Here are three images that show the Crayford in its different positions. On the first image you can see the height of the focuser when it's inside the tube, 6 centimeters. The second image shows the focuser when completely outside, 9 centimeters. So you only have 3 centimeters of travel. On the third image you see the focuser with an extension and completely outside. The total height is 14 centimeters. I have to use the extension on all my 1.25 eyepieces as well as on the Zeiss zoom-eyepiece. For my 32mm Televue plossl, the extension is just a few millimeters to short. I have to pull the eyepiece a little out to get it into focus.

Image 1

Image 2

Image 3

Posted by Math on 11/10 at 07:06 AM
Equipment • (1) CommentsPermalink

Thanks Math,
That is exactly what I needed to know.Looks like it will work perfectly for me.My stock focuser is just too tall for the prime focus adaptor to focus properly.Hope you don’t mind but,I have added your site to my blog roll?!.
Clear skies!!

Posted by Andrew  on  11/10  at  04:34 PM






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