Looks like I will be making extensive edits to my Turntable Calculations page very soon. I learned this week that the stepper motor I had chosen for my turntable project is not guaranteed to meet the specifications listed on the web page from which I had ordered it. Specifically, the quoted number of steps per revolution can vary wildly from motor to motor from what the web site had originally stated as 513 steps/revolution. They now put it at 516, but comments on their user forum say users have received those motors with a variety of gear ratios. So I can’t rely on the motor I originally chose. More details coming soon.