· Question proving they know the difference between S- and Z-twist in thread and how that relates to proper threading of the machine. Attach the diagram, or insert a link to the diagram. (Because if they use thread with the wrong twist for the needle, the machine will jam up.) | · Question proving they know the difference between S- and Z-twist in thread and how that relates to proper threading of the machine. Attach the diagram, or insert a link to the diagram. (Because if they use thread with the wrong twist for the needle, the machine will jam up.) |