English to Russian Tech/Engineering Ships, Sailing, Maritime Winch Installation Procedures / Welding

Extreme care should be taken to ensure the center of the winch drum exactly perpendicular to the cable running to the first sheave. This can be done by average sightings along the flat surface of the winch (sidewall, drum flanges) or with the help of a square to find the true perpendicular centerline. If it is not properly aligned, cable-laying problems may create difficulties and possibly damage the cable, winch and/or personnel.
Источник: http://www.ramwinch.com/pdf/K5UR_Series_Utility.pdf (стр. 26)
Насколько я понял, авторы документа предлагают определять отклонение троса от оси барабана визуально (на глаз). Так ли это?