ME267 L7

• Feed is obtained by a transverse movement of the table at the end of each stroke.
• Shaping and planing are similar operations, both involving the use of a single-point cutting tool moved linearly relative to the workpart.
• In conventional shaping and planing, a straight, flat surface is created by this action.
• The difference between the two operations is illustrated in Figure 1.
• In shaping, the speed motion is accomplished by moving the cutting tool; while in planing, the speed motion is accomplished by moving the workpart.
• Shaping is performed on a machine tool called a shaper.
• The components of the shaper include a ram, which moves relative to a column to provide the cutting motion, and a worktable that holds the part and accomplishes the feed motion.
• The motion of the ram consists of a forward stroke to achieve the cut, and a return stroke during which the tool is lifted slightly to clear the work and then reset for the next pass.
• On completion of each return stroke, the worktable is advanced laterally relative to the ram motion in order to feed the part.
• Feed is specified in mm/stroke (in/stroke).
• The drive mechanism for the ram can be either hydraulic or mechanical.
• In surface grinding, the work is reciprocated (moved back and forth) under the grinding wheel, which is fed down to provide the desired depth of cut.
• The cutting speed, V, and feed per stroke fc are important parameters in shaping and planing.
• Broaching is performed using a multiple-teeth cutting tool by moving the tool linearly relative to the work in the direction of the tool axis, as in Figure 7.
• Parts of a planer machine include the worktable, which is the surface where the part is machined, and the single-point cutting tool, which is the tool that cuts the part.
• Cutting speed is achieved by a reciprocating worktable that moves the part past the single-point cutting tool.
• Surface grinding is used to produce a smooth finish on flat surfaces.
• The construction and motion capability of a planer permit much larger parts to be machined than on a shaper.
• The horizontal spindle surface grinder with a reciprocating table is probably the most common type of surface grinder used in the toolroom.
• It is a widely used abrasive machining process in which a spinning wheel covered in rough particles cuts chips of metallic or nonmetallic substance from a workpiece, making a face of it flat or smooth.
• The machine tool is called a broaching machine, and the cutting tool is called a broach.
• The cutting tool is held in a clapper box so the tool does not damage the workpiece on the return stroke.
• The machine tool for planing is a planer.