Does SGPro focus in one direction without returning?


#1

In the New Year I’m hoping to make the Arduino stepper motor focuser ( https://sourceforge.net/projects/arduinofocuscontrollerpro/).
The pdf instructions raise the issue of backlash in an SCT focus knob. Two solutions are given, add a Crayford focuser or use FocusMax which only focuses in one direction. I’m set on using SGPro and I don’t really want to spend money on a Crayford.
Does SGPro work the same way as FocusMax (i.e. focus in one direction only)?

Actually I don’t understand how FocusMax works in one direction only. It seems to produce a V-curve to find the optimum focus point (as SGPro does) so presumably it will have to wind back to the best position after producing the curve, thus encountering backlash.
Thanks,
Robin


#2

Thanks for looking but I’ve found the answer here. It’s all to do with a backlash setting for the focuser. That gives me the confidence to start buying all the bits and pieces for making it.


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