pjphilli
29-06-2011, 03:54 PM
Hi
I have a Ritchey Chretien 200mm f8 GSO scope fitted with GSO Crayford
focuser. This has a 10:1 vernier knob. I am using a Canon 400D camera which is fairly heavy so when the scope is in the near vertical position
the Crayford focus adjustment has to be able to move the camera "up hill". Hence, the firmness that the adjustment shaft needs to be increased by the adjustment screw so that the camera does not cause the focus to slide back and that firm upward and downward adjustment may be maintained using the main knobs. However, I notice that the 10:1 vernier adjustment seems to have only a weak affect on the focusing movement, ie in the above circumstance the vernier will move the camera down but there is not enough torque to move the camera up.
Is there any way that I can improve the torque applied to the movement shaft by the vernier knob? I hope this all makes sense!
Cheers Peter
I have a Ritchey Chretien 200mm f8 GSO scope fitted with GSO Crayford
focuser. This has a 10:1 vernier knob. I am using a Canon 400D camera which is fairly heavy so when the scope is in the near vertical position
the Crayford focus adjustment has to be able to move the camera "up hill". Hence, the firmness that the adjustment shaft needs to be increased by the adjustment screw so that the camera does not cause the focus to slide back and that firm upward and downward adjustment may be maintained using the main knobs. However, I notice that the 10:1 vernier adjustment seems to have only a weak affect on the focusing movement, ie in the above circumstance the vernier will move the camera down but there is not enough torque to move the camera up.
Is there any way that I can improve the torque applied to the movement shaft by the vernier knob? I hope this all makes sense!
Cheers Peter