steerroger

18 hours ago, John said:

Just bear in mind that you need a cutaway in the focuser drawtube to accommodate the set screw of that adapter.

 

Damn!  I thought it was a grub screw with a key.  I have a JMI one on an old 10" dob. It too needs a cutaway. I wonder it the grub screw method might work on that. 

Thanks everyone!  The Baader 1mm optical length might solve the problem that I mentioned on another thread.

I've just spent a frustrating afternoon, lashing up various combinations for an Explore 102mm f7, for use with a binoviewer. The ES has a focussing travel of 45mm.  To compensate, they supply it with spacer tubes.  These tubes are both about 37mm.  The result is that if the point of focus is fully racked-out without a tube, it is nearly fully racked-in with a tube.  Would it have been too much trouble to have made one of the tubes about 22mm, which would move it from racked-out, to the centre of travel?  Have others found this problem and solved it?

I've just spent a frustrating afternoon, lashing up various combinations for an Explore 102mm f7.  There will be more in another post about this.  Along the way, I examined my collection - 4, I think, 1.25" to 2" adaptors.  Every one has a loose locking screw.  I am not sure if it is the accuracy of the tap used, the die used on the screw, or the poor quality of either piece of metal - This is my guess.  probably the adaptor, as it doesn't get better when a stainless steel socket screw is used.  Why are they all so poor, and does anyone make decent ones?  I know that twist-lock/self centering ones are better, but if you want several, they cost a lot!