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FocusCube Zero step size in microns on RASA 8

Posted: Thu Jun 23, 2022 3:13 am
by haythrower
Anybody have any ideas what this number is or how to calculate it?

Re: FocusCube Zero step size in microns on RASA 8

Posted: Tue Sep 27, 2022 1:31 am
by AZJohnnyC
Hi. You can easily calculate the step size in microns by first measuring (in millimeters) the diameter of the RASA 8 focuser rod that you're connecting the FocusCube to. Next, multiply that by pi (3.1415) in order to arrive at the circumference of the focuser rod. Then divide the result by the Steps Per Cycle of the FocusCube. Finally, dividing this by 0.001 gets you the resolution in microns.

As an example, I've just connected my FocusCube 2 to my Williams Optics ZenithStar 61. The focuser rod on my telescope has a diameter of 6mm. Multiplying that by pi gives me a rod circumference of 18.849mm. Dividing this by the Steps Per Cycle of the FocusCube 2 (11,510) gives me 0.0016376. Finally, dividing this by 0.001 shows a resolution of 1.6 microns.

Hope this helps!

John