To contact the author by email.
Bewildered? See if the tutorial helps.
Results of your calculation:
Basically, fill in the gear-related values you want, leave blank the value you wish to have calculated.
Ranges of values can be indicated by e.g. "500-10000x500", which might be used for rpm from 500 to 10000 by steps of 500. Or sets of values can be used; in particular you can list many gears, e.g. "3.3,2.4,1.8,1.4,1.0".
the request when it's complete, or and start over.
Reorder calculation elements: (definitely you usually want to leave this blank)
the request when it's complete.