Hi Martha, you might want to read my posts on page 3 of this post:

indilib.org/forum/ekos/11668-new-focus-a....html?start=24#82726

Basically, you shouldn't need to guess the step size, it should ideally be calculated from your CFZ size, EAF/focuser drawtube travel, and a couple of user selectable parameters. See the formula for New CFZ as defined in the post above. Then you'll want to know (or measure) your focuser travel per revolution and match this up to the EAF counts/rev. Set your step size to be somewhere between 1/2 and 1 CFZ. You don't want to jump over the CFZ, and if you set it too small, you'll just waste time during focus jumping within the same CFZ. As for how the EAF is mounted, If I remember correctly from the user manual, you should not mount on the 10:1. The counts/revs is already plenty high enough to do fine focus work as is. Expect backlash on the order of 85 counts (That's about where mine was when I tested, and it was confirmed by others in the forum with EAF).... Good luck & CS, Doug S

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