A 3-module, 20° hob is used to cut a spur gear. The hob is right-handed with a lead angle of 2°40', a length of 75 mm, and an outside diameter of 75 mm Make a full-size sketch of the hub cutting a 48-tooth spur gear. The gear blank is 38 mm wide. Show the pitch cylinder of the hob on top of the gear blank with the pitch helix of the hob in correct relation to the pitch element of the gear tooth. Show three tooth elements on the gear and 1
turns of the thread on the hob; position these elements by means of the normal circular pitch. Label the axis of the hob and gear blank, the lead angle of hob, and the direction of rotation of the hob and gear blank.