It was established an expediency of adjusting of the stroke of the slider 7 only within such limits, taking into account the permissible values of transmission angles. Further increase of the angle will lead to jamming of the mechanism links. As a result of the study, it was established that the stroke of the needle guide 7 can be adjusted in the range from 18 to 23 mm. The conducted computer modeling and corresponding kinematic analysis in SOLIDWORKS Motion confirmed the correctness of the analytical calculations and the operability of the proposed mechanisms.