I have place the spreadsheet I created to model the periodic error of the mechanical worm/wheel system in the Mount Related file folder. There are 2 sheets, the first sheet model the worm and the second sheet models 200 minutes of the combined worm/wheel system. I had to limit the amount of time in the second sheet (12000 seconds) because the full 24 hours of the data was > 30 Mb and Yahoo did not allow a file that large to be uploaded. I have not provided any explanation of the equations, but there are column headers that describe the value.
You can set the mechanical error (inches) for offset and run-out and the period.
Give it a try.
Director Electrical Engineering
Explore Scientific, LLC.