Control DataTable to CSV toString() formatting
What's the point of dataTable = newMyDataTable;? Why not simply work with newMyDataTable directly? Note that newMyDataTable is a bad variable name anyway.



Ditto fileId: this is only used to pass to PathMaker, so why then not simply use newMyDataTable.TableName?



Ditto dataLine: why not work with dr.ItemArray directly?



writtingLock has a spelling error.



What is dc? Ditto dr? Use descriptive names; using abbreviations isn't making your code faster.



Why assign dateTime and otherData when you could easily make this one line? Even better: why not move this code -- including the string.Join -- to separate methods?

Example:

string.Join(",", dr.ItemArray
     .Where(o =&gt; o.GetType() == typeof(DateTime))
     .Select(x =&gt; ((DateTime)x).ToString(dateTimeFormat)));




Why assign lineToWrite when you could simply write swr.WriteLine(dateTimeToWrite + "," + otherDataToWrite);?



filePath is a property, so it should be PascalCase.