Great new 13" Binocular Newt in the Netherlands

[erick (Eric)]

Originally Posted by erick

...... Adjustable IPD is too difficult, but I guess I could try regular focussers plus diagonals plus 2" helical focussers above that and push the primaries well up the tubes - but that's getting a bit over the top with equipment, then, at the focusser! .....

Moving ahead. Here is the prototype IPD and focus adjustment. The focusser to provide IPD adjustment (tweaking both sides the same amount) and the Borg helical focusser for individual eyepiece focus. I've retreated to a 1.25" only eyepiece train. Now to work out how far to move the primary mirror up the tube. At the moment I can focus on objects about 20m from the scope

[Satchmo]

Hi Eric, with this set up I doubt you'll see more than 2/3 your aperture at the focal plane of the telescope- thats at a guess. have you done any scale drawing of this section to see how much of the F6 cone you can get through from the point of the secondary mirror ?

If you can give me the diameter of your secondary , the distance from the secondary to the tertiary mirror , the diameter of the aperture at the exit of the `tertiary mirror' star diagonal and the distance from the centre of the `tertiary' diagonal to the focal plane, I can run it through Binewt designer and we can start to get an idea of what is happening there.

Are those the lowest profile GSO Crayfords or the stock ones that came on the tubes?

Maybe start a new thread for your build ?

PS If you are going the route of non rotating tubes - make sure you bolt the two tubes as close as you can together . Don't allow a space for your head between them etc - it will make the frame to join the two tubes together , massive and so will the mount...