the leading side of the line to move relative to the line guide and facilitate the conduction of heat generated in the line away from the line and away from the leading side wall bearing surface still focusing on the first line 14 and on structural and operational aspects associated therewith in detail the first line 14 is wound around a spool 32 in a lower cavity 34 of the spool and during rotation and cutting extends from the spool through a line port 36 through a lower cover 38 of the housing 12 between the leading and trailing side wall bearing surfaces 20 and 22 and above a floor surface 40 of the first line guide 24 see fig1 and 2 due to the centrifugal force on the line as it rapidly moves in its circular pattern the line will tend to contact and push against the leading side wall bearing surface 20 however due to the relative close proximity of an inner linear surface portion 42 of the trailing side wall bearing surface to a linear surface portion 44 of the leading side wall bearing surface the line is expected to regularly also push and bear against the trailing side wall surface even when the line is not whipping backwards as a result of e g encountering heavy vegetation or articles which it cannot cut during the just mentioned whipping backwards which essentially is a normal and expected occurrence the line 14 will generally move toward an outer linear.