Barry, from much painfull experience, and lots of experimentation, bolted hard down (clamped, no rings) and unadjustable is the only way (including the cam, unfocusable, adjustment not not needed once done 1st time). If your guide cam is wide field (say the ST80) you will always find a guide star.
The cost, grief, extra weight, fexure etc in any kind of adjustment is just not worth it.
Barry, from much painfull experience, and lots of experimentation, bolted hard down (clamped, no rings) and unadjustable is the only way (including the cam, unfocusable, adjustment not not needed once done 1st time). If your guide cam is wide field (say the ST80) you will always find a guide star.
The cost, grief, extra weight, fexure etc in any kind of adjustment is just not worth it.
I think Fred's hit the nail on the head. Today's guide cameras are good enough to find a guide star wherever you point the scope.
Geoff
I've replaced my adjustable rings for solid rings to use with the ST80.
I'm very happy I did, it eliminates any unnecessary flexure as stated and the guider's always found guide stars so far.
Better late than never.
I have a wonderful guide-scope, in equally wonderful guide-scope rings, but of late have opted for a slightly different approach.
A cobbled up 50mm finder, minus the eyepiece, but with a QHY5 stuffed in the eyepieces place.
Fitted in a set of finder rings which are adjustable, but which don't need to be adjustable.
Try it, it works for me, and imaging at 1800mm focal length as well.
Now this system transfers to whatever imaging scope (or camer lens) I am using.
Gary
I'm with Fred and Geoff here. Guide rings with delrin or PTFE-tipped adjuster scews are the devils work, and like any axially-adjustable device, introduce all sorts of potential flexure problems - not to mention tube scratches and indentations, accidental rotations, weight, etc, etc.
I opt for double clamshells or rings to hold the entire absolutely assembly rigid - and rely on the modern guide camera (QHY5 in my case) to be able to discern the faintest star to guide on. It's a rare thing that I can't find one anywhere I point it - and I run a 60mm guidescope!
Your system looks interesting though Barry - because you don't have adjuster screws but solidly-clamped rings. You have the ability to axially offset your guidescope still by adjustments in the base. I guess that as long as your threads and buffers soak up all possible flexure due to sloppiness then it looks great. How heavy is it?
