This app is centering alignment calculator of shaft coupling between driver and driven machine that can get calculation result exactly and immediately!! First of all.You will input three data that distance between adjust side machines set bolt and from adjust side machines front set bolt to measurement plane of dial gauge and rotation diameter of dial gauge.then you will input up and down direction shaft coupling eccentricity numeric present value.You can know the required shim liner thickness of shaft alignment center.Finally you have to decide the shim liner in you have.