Guider Scope- Modified Orion/ Celestron 50mm finder scope
Modified guide scope is firmly clamped to the underside of the AP dovetail base......min. flexure issues!
Guide Scope- Modification Steps
I used a 50mm finder scope from Orion (same type as Celestron). Unscrewed rear eyepiece and used a piece of frosted plastic to accurately, visually determine the focal point (~178mm) dimension.
I used my small bench-top lathe to removed the excess length of the tube
I then machined a 1-1/4 to 2" adapter to be shrunk-fit inside the ID of the 50mm tube.
Since my focal length dimension was fairly accurate, when I mounted the 1-1/4 nosepiece of the auto-guide camera, the objective lens only required a small focal adjustment. Note: all dimensions needed to add up to the FL (depth to chip surface+ adapter space+ tube length.
Machined a custom clamp for mounting the scope
With the entire assembly clamp mounted, it was easy to adjust the objective lens and lock-it with the threaded lock-ring that these scopes use.
I have never touched it after running the focus routine in MaximDl and locking the setting down.
FIELD OF VIEW USING ORION SSAG: 2.1deg x 1.7deg