I am using a Pegasus Astro Focus Cube 2 on a Takahashi Epsilon 160ED stock focuser. When focusing OUT (focus tube is extending and since the camera is mounted on top of the OTA it is generally moving against gravity - opposite of a refractor) and the backlash parameter is set to my current best estimate (31 steps) the focus motor moves beyond the requested number of steps and then returns to the requested value. This happens for every requested move OUT - not just after reversing direction from moving IN. When focusing IN (focus tube in retracting - assisted by gravity) the focus motor just moves the focus tube directly to the value requested (there is no overshoot and then return to the requested value). This is true for all focus algorithms.

Is this the way the backlash compensation is designed to work?

I have setup a sensitive dial gauge to monitor absolute motion of the camera and focus tube. I am making measurements by manually entering numbers in the “Desired absolute focuser position” box of the Ekos “Focus” window and executing the “Go to absolute focus position” button to the right of the entry box. I watch the reading of the “Current absolute focuser position” window and the corresponding dial indicator reading to monitor the motion of the focuser. I realize this is not necessarily what happens during the execution of an Auto Focus algorithm when doing an actual Auto Focus using a real star.

The problem is if the focuser reverses direction from focusing OUT to focusing IN, backlash is not implemented. And if the focuser continues to move IN, backlash is never implemented. It seems like the overshoot and return to requested position should work every time the direction is reversed -no matter whether it is moving IN or OUT? What am I not understanding about backlash compensation?

Thanks for any guidance and explanation of what I may be doing wrong.

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