Hello, I have been trying to set up a free body diagram for a power screw in a horizontal application. Every example I find they are using a power screw to lift or lower a load not move it left to right. I have attached the example from the text book, along with my work so far. Looking at the text book example why do they break the Normal force in to components when summing forces? In most physics text books the Normal force is left intact and other forces, such at weight, are broken down. Second, on the work2.pdf when I am summing forces for the left traverse condition, I get the Force of friction in the x equal to the negative x component of the normal force. Is this right? Third, should there be a thrust force causing the nut to move horizontally?