an apparatus for selectively changing the distance of needle travel in a sewing machine in which the needle is carried by a needle clamp and reciprocated by a crank driven control lever along a pathway defined by a fixed guide bar . one end of the control lever has a lever pivotably connected thereto and the opposite end of this lever is pivotably connected to an eccentrically mounted and selectively positionable pin that protrudes from the machine &# 39 ; s housing . each of the available positions of the pin provide a means for effecting a change in the distance a needle travels during seaming for the purpose of accommodating workpieces of different thicknesses .