Hi I was reading balancing of reciprocating masses and read about balancing of force along the line of stroke for a simple reciprocating piston. The force particlualry primary force along the line of stroke was mw^2r cosA. Now this is supposed to be a cosine component of a mass m attached at the e0nd of crank or connecting rod. So a mass B is attached opposite to crank such that it's centrifugal force counteacts the supposed mass's centrifugal force(such that m w^2 r1 cosA= B w^2 r2 cosA). Then it was written that by this method we get unbalanced force prependicular to the stroke because the new mass B attached also has sine component which is prependicular to the line stroke. Thus the above method just shifts the primary unbalanced force from parallel to prependicular line of stroke. Upto this it's ok. But then it was written that, So it is prefered to take m r1 = C B r2 where C<1 is the factor that introduces partial balancing along the line of stroke This is what i didn't understand. Why and how C is introduced?