the inclination of the guideway 41 in the present invention may be controlled by an electromechanical feed actuator indicated generally at 28 the electromechanical feed actuator 28 is connected to a link 46 pivoted at 47 to a rock arm 48 which is secured on a rock shaft 49 to which the guideway 41 is affixed the electromechanical actuators 27 and 28 may be constructed alike and may take the form of construction disclosed in detail in the u s patent application ser no 431 649 filed jan 8 1974 of philip minalga which is incorporated herein by reference for an understanding of the present invention the following brief description of the electromechanical actuator 28 should suffice the actuator 28 includes a u shaped magnetically permeable yoke 113 which may be secured to the sewing machine frame by any suitable means secured to each of the two inner faces of the yoke is a permanent magnet 114 these magnets are magnetized across the small dimension so as to present the same polarity to the opposed inner faces thereof a single center leg 115 of magnetically permeable material positioned centrally between the magnets provides both a flux return path and a guide on which is slidably mounted a bobbin 118 carrying a winding the bobbin is made of light weight insulating molded plastic and.